Multipolar neurons are neurons that have one axon and many dendrites. These dendrites or multi-processes give the neuron many connection points to other neurons. Multipolar neurons function as either...
atterns in a network, it was found that the weighted hidden neuron activations feeding the output neuron(s) displayed remarkably consistent patterns. Specifically, redundant hidden neurons exhibit weighted activation patterns that are highly correlated. Therefore, the paper proposes identifying hidden neurons with weighted activation patterns that are highly correlated and using one neuron to represent a group of correlated neurons. The paper proposes to automate this process in two steps: 1) Map the correlated weighted hidden neuron activation patterns onto a self organising map; and 2) Form clusters of SOM neurons themselves to find the maximum likely number of clusters of correlated activity patterns. The likely number of clusters on the map indicates the required number of hidden neurons to model the data. The paper highlights the approach using an example and demonstrates its application to solving two problems including a realistic problem of predicting river flows in a catchment in New ...
Traditionally, cultures of primary cortical neurons are prepared from embryonic animals because at prenatal stages neurons have not yet developed extensive axonal and dendritic arbors and are not highly innervated, thus rendering the cells less susceptible to damage during dissociation of the neuronal tissue. The appropriate developmental age for preparing primary cultures of any cell type is determined by the time at which the cells of interest are generated and abundant. Most cerebral cortical neurons are generated between embryonic days (E) 11 and 17 in the mouse (embryos being considered 0.5 days old when a vaginal plug is detected in the morning). Here we describe a method to obtain short-term cultures of mouse primary cortical neurons at E15.5 and a practical application using fluorescent immunocytochemistry.
Jochen Meier Ivonne Strmel Radu Iosub Sonja Schmidt and Rosemarie Grantyn Developmental Physiology Johannes Mller Institute Humboldt University Medical School (Charit) Berlin Germany Efficient delivery of DNA to primary neuronal cell cultures is of critical importance,Effectene,Transfection,Reagent,provides,efficient,gene,delivery,,,,,,,,,,,,to,primary,neuronal,cell,cultures,biological,advanced biology technology,biology laboratory technology,biology device technology,latest biology technology
Suprathreshold corticostriatal responses recorded from medium spiny neurons (MSNs) from the direct and indirect pathways of the basal ganglia are different. Their differences readily distinguish D1- and D2-type receptor expressing MSNs in both bacterial artificial chromosome-transgenic mice and their control littermates as well as in rats: indirect pathway neurons are more excitable than direct pathway neurons revealing autoregenerative spikes underlying their spike trains, whereas direct pathway neurons exhibit more prolonged plateau potentials and spike trains. SFK 81297, a selective agonist for D1-class receptors enhanced corticostriatal responses in direct pathway neurons, while quinelorane, a selective agonist for D2-class receptors reduced orthodromic and autoregenerative responses in indirect pathway neurons thus making both neuron classes similarly excitable. Because dopaminergic postsynaptic actions target CaV1 (L) class voltage-gated calcium channels in MSNs, we hypothesized that these
Elimination of spinal neurons that possess the SPR using SP-SAP offers the unique opportunity to determine the role of SPR-expressing neurons, as well as other neurons, in pain processing. SP-SAP induced specific degeneration of neurons expressing SPR receptors. This observation was made previously (Mantyh et al., 1997; Nichols et al., 1999) and is supported by present data. An interesting finding of the present study was the proportional change in the functional classification of spinal neurons encountered in animals pretreated with SP-SAP. The proportion of HT neurons encountered in control animals was ∼36%, whereas only 7% of the neurons identified in SP-SAP-treated animals were HT. This suggests that SP-SAP targeted primarily HT neurons. It has been shown in cats that HT neurons possess more SPRs than WDR neurons (Ma et al., 1996, 1997), suggesting that HT neurons are more vulnerable to SP-SAP because of the greater number of SPRs on these neurons.. The absence of sensitization and windup ...
Other articles where Multipolar neuron is discussed: human nervous system: The peripheral nervous system: Motor ganglia have multipolar cell bodies, which have irregular shapes and eccentrically located nuclei and which project several dendritic and axonal processes. Preganglionic fibres originating from the brain or spinal cord enter motor ganglia, where they synapse on multipolar cell bodies. These postganglionic cells, in turn, send their…
Primary sensory neurons in the DRG play an essential role in initiating pain by detecting painful stimuli in the periphery. Tissue injury can sensitize DRG neurons, causing heightened pain sensitivity, often leading to chronic pain. Despite the functional importance, how DRG neurons function at a population level is unclear due to the lack of suitable tools. Here we developed an imaging technique that allowed us to simultaneously monitor the activities of >1,600 neurons/DRG in live mice and discovered a striking neuronal coupling phenomenon that adjacent neurons tend to activate together following tissue injury. This coupled activation occurs among various neurons and is mediated by an injury-induced upregulation of gap junctions in glial cells surrounding DRG neurons. Blocking gap junctions attenuated neuronal coupling and mechanical hyperalgesia. Therefore, neuronal coupling represents a new form of neuronal plasticity in the DRG and contributes to pain hypersensitivity by hijacking ...
There are various types of enteric neurons. initial with top cell routine leave at E11.5 accompanied by neurofilament-M neurons Telotristat Etiprate calcitonin gene-related peptide neurons (top cell routine leave for both at E12.5-E13.5) tyrosine hydroxylase neurons (E15.5) nitric oxide synthase 1 (NOS1) neurons (E15.5) and calretinin neurons (P0). Almost all myenteric neurons got exited Telotristat Etiprate the cell routine by P10. We didnt observe any EdU+/NOS1+ myenteric neurons in the tiny intestine of adult mice pursuing EdU shot at E10.5 or E11.5 that was unexpected as previous research show that NOS1 neurons can be found in E11.5 mice. Research using the proliferation marker Ki67 uncovered that hardly any NOS1 neurons in the E11.5 and E12.5 gut had been proliferating. Nevertheless Cre-lox-based hereditary fate-mapping revealed a little sub-population of myenteric neurons that seems to exhibit NOS1 just transiently. Jointly our outcomes confirm a romantic relationship between enteric ...
New research involving people diagnosed with Lou Gehrigs disease sheds light on how individual neurons control muscle movement in humans - and could help in the development of better brain-controlled prosthetic devices.
Activation of MLK and c-Jun is required for the death of GDNF-deprived sympathetic neurons. (A) Quantitation of neurons with strong nuclear immunostaining for phosphorylated c-Jun expressed as a percentage of all neurons. Neurons were deprived of neurotrophic factors in the presence of caspase inhibitor BAF for 48 h and immunostained with antibodies to phosphorylated serines 63 or 73 of c-Jun. Control neurons maintained with GDNF or NGF were stained as well. The mean ± SEM of four (for P-Ser-63) or three (for P-Ser-73) independent cultures is shown. Neurotrophic factor-maintained and -deprived groups were compared by t test. (B) Typical examples of weak (GDNF-deprived neurons) or strong (NGF-deprived neurons) nuclear immunostaining. Corresponding phase-contrast images are shown on the right column. Levels of the fluorescent images were equally enhanced with Adobe Photoshop software. Bar, 10 μm. (C) GDNF- or NGF- deprived sympathetic neurons were microinjected with expression plasmid encoding ...
GABAergic pathways in the brainstem play an essential role in respiratory rhythmogenesis and interactions between the respiratory and cardiovascular neuronal control networks. However, little is known about the identity and function of these GABAergic inhibitory neurons and what determines their activity. In this study we have identified a population of GABAergic neurons in the ventrolateral medulla that receive increased excitatory post-synaptic potentials during inspiration, but also have spontaneous firing in the absence of synaptic input. Using transgenic mice that express GFP under the control of the Gad1 (GAD67) gene promoter, we determined that this population of GABAergic neurons is in close apposition to cardioinhibitory parasympathetic cardiac neurons in the nucleus ambiguus (NA). These neurons fire in synchronization with inspiratory activity. Although they receive excitatory glutamatergic synaptic inputs during inspiration, this excitatory neurotransmission was not altered by blocking
OCT intensity and phase fluctuations correlated with activity-dependent neuronal calcium dynamics in the Drosophila CNS [Invited]
NETMORPH is a modular simulation tool for building synaptically connected networks with realistic neuron morphologies. Axonal and dendritic morphologies are created by using stochastic rules for the behavior of individual growth cones, the structures at the tip of outgrowing axons and dendrites (collectively called neurites) that mediate neurite elongation and branching. In brief, each growth cone has at each time step a probability to elongate the trailing neurite, to branch and produce two daughter growth cones, and to turn and change the direction of neurite outgrowth. The parameter values of the outgrowth model can be optimized so as to obtain an optimal match with the morphology of specific neuron types. Neurons are positioned in 3D space and grow out independently of each other. Axons and dendrites are not guided by any extracellular cues. Synapses between neurons are formed when crossing axonal and dendritic segments come sufficiently close to each other. NETMORPH is written in C++ and ...
Video articles in JoVE about gabaergic neurons include Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals, Reliable Identification of Living Dopaminergic Neurons in Midbrain Cultures Using RNA Sequencing and TH-promoter-driven eGFP Expression, The Neuroblast Assay: An Assay for the Generation and Enrichment of Neuronal Progenitor Cells from Differentiating Neural Stem Cell Progeny Using Flow Cytometry, Viral-mediated Labeling and Transplantation of Medial Ganglionic Eminence (MGE) Cells for In Vivo Studies, Inhibitory Synapse Formation in a Co-culture Model Incorporating GABAergic Medium Spiny Neurons and HEK293 Cells Stably Expressing GABAA Receptors, Intracortical Inhibition Within the Primary Motor Cortex Can Be Modulated by Changing the Focus of Attention, Protocol for the Differentiation of Human Induced Pluripotent Stem Cells into Mixed Cultures of Neurons and Glia for Neurotoxicity Testing, Tuning in the
NEURON files from the paper: On the mechanisms underlying the depolarization block in the spiking dynamics of CA1 pyramidal neurons by D.Bianchi, A. Marasco, A.Limongiello, C.Marchetti, H.Marie,B.Tirozzi, M.Migliore (2012). J Comput. Neurosci. In press. DOI: 10.1007/s10827-012-0383-y. Experimental findings shown that under sustained input current of increasing strength neurons eventually stop firing, entering a depolarization block. We analyze the spiking dynamics of CA1 pyramidal neuron models using the same set of ionic currents on both an accurate morphological reconstruction and on its reduction to a single-compartment. The results show the specic ion channel properties and kinetics that are needed to reproduce the experimental findings, and how their interplay can drastically modulate the neuronal dynamics and the input current range leading to depolarization block ...
The researchers focused on brain cells that transmit information from the brains cortex. Some of the cortical neurons are responsible for muscle control and are the ones lost or damaged in people with spinal cord injuries and ALS.. These stem cell-derived neurons can grow nerve fibers between the brains cerebral cortex and the spinal cord, so this study confirms the use of stem cells for therapeutic goals, the research teams leader, James Weimann, said in a news release from the Society for Neuroscience.. In laboratory dishes, the researchers grew stem cells that were precursors to cortical neurons until the cells displayed many of the characteristics of mature neurons. The new neurons were then transplanted into the cortex of newborn mice, specifically into regions that control vision, touch and movement.. The transplanted neurons grew into the appropriate brain structures and avoided inappropriate areas, the researchers reported.. The study is in the Jan. 20 issue of the Journal of ...
Neurons are cells that make up our brain and spinal cord allowing us to process our surroundings. They fire electric and chemical signals when the potential difference across their cell membrane reaches a critical voltage.. Unlike other body cells, neurons dont undergo mitosis (cell splitting). Instead, neural stem cells can generate new specialized neurons by differentiating into neuroblasts that, upon migration to a specific area, can turn into a neuron. The neuroblasts can undergo mitosis.. Neural stem cells, like all stem cells, may sit around for long periods of time before they generate a neuroblast. In the 1960s, scientists had the first indication that neurons might be generated in an adult rodent brain but it wasnt until the 1990s that scientists discovered the neural stem cells and the generation of neurons in the adult rodent brain. So it has long been wondered whether or not humans get new brain cells.. In the late 1990s scientists studying neurogenesis, the creation of new ...
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Adult mouse DRG neurones have been maintained for 14 days in cultures where non-neuronal cell proliferation was inhibited by the inclusion of 5 × 10(−6) microM-cytosine arabinoside (AraC) in the medium from the onset of culture. On uncoated plastic neurone numbers significantly declined in the absence of non-neuronal cell outgrowth compared with uninhibited co-cultures. However, when neurones were maintained in the presence of AraC on certain coated surfaces this decrease in neurone numbers was not observed. Combinations of fibronectin (FN) and laminin (LAM) proved most effective for 7 and 14 days in vitro, although either was beneficial if used separately. Microexudates produced by the fibroblast line, 3T6, also significantly improved neuronal counts for 14 days in vitro. However, a microexudate derived from primary cultures of mouse hepatocytes, although advantageous for 7 days in vitro, was not effective in maintaining neurones over the 14-day culture period, reminiscent of previous ...
Fetal Neuron Grafts Pave the Way for Stem Cell Therapies Marcia Barinaga A decade of experimental treatments using fetal neurons to replace brain cells that die in Parkinsons disease can provide lessons for planning stem cell therapies Swedish neuroscientist Anders Björklund and his colleagues may have caught a glimpse of what the future holds for the treatment of failing organs. For more than 10 years, Björklund has been part of a team at Lund University in Sweden that has been grafting neurons from aborted fetuses into the brains of patients with Parkinsons disease. In many cases, the transplanted cells have dramatically relieved the patients symptoms, which include slowness of movement and rigidity. That is just the kind of therapy that stem cell researchers hope to make routine for treating all sorts of degenerative diseases, if they can coax the cells to develop into limitless supplies of specific cell types that can be used to repair or replace damaged organs. Although the current ...
Alzheimers Disease (7) Amyotrophic Lateral Sclerosis (8) Antibodies (6) Apoptosis Detection (7) axonal regeneration (3) Cancer Research (7) Cerebral Ischemia (4) diabetes (6) e-18 Primary Rat Neurons (11) embryonic stem cells (19) enteric nervous system (5) FLICA (5) FLIVO (2) Glia Markers (5) Glial Markers (15) Hippocampal Neurons (6) human embryonic stem cells (3) Human Neural Progenitors (10) Human Neurons (6) Hypothalamic Neurons (1) Immunocytochemistry (5) Immunofluorescence (12) Immunohistochemistry (23) inflammatory response (13) MitoPT (2) Multiple Sclerosis (11) Neural Crest (2) Neural Progenitor Cells (7) Neural Stem Cell Markers (8) Neurofilament Markers (12) Neurogenesis (5) Neuronal Markers (14) Neuropathic Pain (19) Neuropeptides (7) Neuroprotection (4) neuroscience (3) Neurotoxicity (9) Neurotransmission (10) Nociceptive Pain (18) Obesity Research (6) Oligodendrocytes (8) Otx2 Antibody (2) Pain Research (27) Parkinsons Disease (10) placental mesenchymal stem cells (1) Polcaspase ...
Destruction and death of neurons can lead to neurodegenerative diseases. One possible way to treat neurodegenerative diseases and damage of the nervous system is replacing damaged and dead neurons by cell transplantation. If new neurons can replace the lost neurons, patients may be able to regain the lost functions of memory, motor, and so on. Therefore, acquiring neurons conveniently and efficiently is vital to treat neurological diseases. In recent years, studies on reprogramming human fibroblasts into neurons have emerged one after another, and this paper summarizes all these studies. Scientists find small molecules and transcription factors playing a crucial role in reprogramming and inducing neuron production. At the same time, both the physiological microenvironment in vivo and the physical and chemical factors in vitro play an essential role in the induction of neurons. Therefore, this paper summarized and analyzed these relevant factors. In addition, due to the unique advantages of physical
TY - JOUR. T1 - Involvement of mitochondrial K+ release and cellular efflux in ischemic and apoptotic neuronal death. AU - Liu, Dong. AU - Slevin, John R.. AU - Lu, Chengbiao. AU - Chan, Sic L.. AU - Hansson, Magnus. AU - Elmér, Eskil. AU - Mattson, Mark P.. PY - 2003/8. Y1 - 2003/8. N2 - We measured and manipulated intracellular potassium (K+) fluxes in cultured hippocampal neurons in an effort to understand the involvement of K+ in neuronal death under conditions of ischemia and exposure to apoptotic stimuli Measurements of the intracellular K+ concentration using the fluorescent probe 1,3-benzenedicarboxylic acid, 4,4′-[1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7, 16-diyl-bis(5-methoxy-6,2-benzofurandiyl)]bis-, tetrakis [(acetyloxy) methyl] ester (PBFI) revealed that exposure of neurons to cyanide (chemical hypoxia), glutamate (excitotoxic insult) or staurosporine (apoptotic stimulus) results in efflux of K+ and cell death. Treatment of neurons with 5-hydroxydecanoate (5HD), an ...
TY - JOUR. T1 - Selective lesion of the hippocampus increases the differentiation of immature neurons in the monkey amygdala. AU - Chareyron, Loïc J.. AU - Amaral, David G. AU - Lavenex, Pierre. AU - Rakic, Pasko. PY - 2016/12/13. Y1 - 2016/12/13. N2 - A large population of immature neurons is present in the ventro-medial portion of the adult primate amygdala, a region that receives substantial direct projections from the hippocampal formation. Here, we show the effects of neonatal (n = 8) and adult (n = 6) hippocam-pal lesions on the populations of mature and immature neurons in the paralaminar, lateral, and basal nuclei of the adult monkey amygdala. Compared with unoperated controls (n = 7), the number of mature neurons was about 70% higher in the paralaminar nucleus of neonate- and adult-lesioned monkeys, and 40% higher in the lateral and basal nuclei of neonate-lesioned monkeys. The number of immature neurons in the paralaminar nucleus was 40% higher in neonate-lesioned monkeys and 30% ...
New York University researchers have created a developmental atlas of gene expression in neurons, using gene sequencing and machine learning to categorize more than 250,000 neurons in the brains of fruit flies. Their study, published in Nature, finds that neurons exhibit the most molecular diversity during development and reveals a previously unknown type of neurons only present before flies hatch.. Diversity of the different cell types that make up our brains can only be fully understood in light of their developmental history, said NYU Biology Professor Claude Desplan, the studys senior author.. Brains are composed of thousands of different types of neurons. Despite sharing the same genetic information, neurons achieve this diversity by turning on different sets of genes in each neuron type and at each point in their development. To understand the diversity of brain cells, researchers have long studied fruit flies, whose brains, although much simpler than those of humans, can be used as a ...
J. Z. YOUNG; Cellular Basis for Long-Term Neuronal Adaptation. Biochem Soc Trans 1 October 1978; 6 (5): 839-841. doi: https://doi.org/10.1042/bst0060839. Download citation file:. ...
Determining the neuronal circuitry responsible for specific behaviors is a major focus in the field of neurobiology. Activity-dependent immediate early genes (IEGs), transcribed and translated shortly after neurons discharge action potentials, have been used extensively to either identify or gain genetic access to neurons and brain regions involved in such behaviors. By using immunohistochemistry for the protein product of the IEG c-Fos combined with retrograde labeling of specific neuronal populations, precise experimental timing, and identical data acquisition and processing, we present a method to quantitatively identify specific neuronal subpopulations that were active during social encounters. We have previously used this method to show a stronger recruitment of ventral hippocampal neurons that project to the medial prefrontal cortex, compared to those that project to the lateral hypothalamus, following social interactions. After optimization of surgeries for the injection of retrograde tracers,
Protecting nerve cells from losing their characteristic extensions, the dendrites, can reduce brain damage after a stroke. Neurobiologists from Heidelberg University have demonstrated this by means of research on a mouse model. The team, led by Prof. Dr Hilmar Bading in cooperation with Junior Professor Dr Daniela Mauceri, is investigating the protection of neuronal architecture to develop new approaches to treating neurodegenerative diseases.
Transplantation studies suggest that the laminar fates of cerebral cortical neurons are determined by environmental signals encountered just before mitosis. In ferret, E29 progenitor cells normally produce neurons of layers 5 and 6. When transplanted during S-phase into an older ventricular zone, E29 progenitors produce neurons that change their fates and migrate to layer 2/3; however, cells transplanted later in the cell cycle migrate to their normal deep-layer positions even in an older environment (McConnell and Kaznowski, 1991). Here we utilize three culture systems to investigate the nature of the environmental signals involved in laminar specification. E29 cells were first cultured at low density to ascertain whether cell contact and/or short-range cues are required for deep layer specification. Neurons transplanted after a short time in low-density culture failed to adopt their normal fates and migrated instead to the upper layers. When crude cell contacts were restored by pelleting E29 ...
Here, based on our previous work on linear synaptic filtering [1-3], we build a general theory for the stationary firing response of integrate-and-fire (IF) neurons receiving stochastic inputs filtered by one, two or multiple synaptic channels each characterized by an arbitrary timescale. The formalism applies to arbitrary IF model neurons, and to arbitrary forms of input noise (i.e., not required to be Gaussian or to have small amplitude), as well as to any form of synaptic filtering (linear or non-linear). The theory determines with exact analytical expressions the firing rate of an IF neuron for long synaptic time constants using the adiabatic approach. The correlated spiking (cross-correlations function) of two neurons receiving common as well as independent sources of noise is also described (see figure 1). The theory is exemplified using leaky, quadratic and noise thresholded IF neurons (LIF, QIF, NTIF). Although the adiabatic approach is exact when at least one of the synaptic timescales ...
BDNF and nitric oxide signaling both contribute to plasticity at glutamatergic synapses. However the role of combined signaling of both pathways at the same synapse is largely unknown. Using NO imaging with diaminofluoresceine in cultured hippocampal neurons we analyzed the time course of neurotrophin induced NO signals. Application of exogenous BDNF, NT-4, and NT-3 (but not NGF) induced NO signals in the soma and in proximal dendrites of hippocampal neurons that were sensitive to NO synthase activity, TrkB signaling, and intracellular calcium elevation. The effect of NO signaling on neurotrophin secretion was analyzed in BDNF-GFP and NT-3-GFP transfected hippocampal neurons. Exogenous application of the NO donor sodium-nitroprusside markedly inhibited neurotrophin secretion. However, endogenously generated NO in response to depolarization and neurotrophin stimulation, both did not result in a negative feedback on neurotrophin secretion. These results suggest that a negative feedback of NO signaling on
Rabbit Polyclonal to OR10J5 adherent monolayer tradition solution to examine variations in effectiveness of neural differentiation, PKO and WT Sera cells were differentiated into neurons from the adherent monolayer tradition technique. Morphological changes had been observed 20350-15-6 manufacture throughout a differentiation period, and immunocytochemistry was performed with MAP2, an adult neuron marker. There have been no variations in the morphology or differentiation of MAP2-positive cells between WT and PKO cells (Fig. 1A). Particularly, the effectiveness of neural differentiation into dopaminergic neurons demonstrated no difference between PKO and WT Sera cells, as dependant on immunocytochemistry with TH, a dopaminergic neuron marker (Fig. 1B). Real-time RT-PCR evaluation with dopaminergic neuron markers such as for example Nurr1, Pitx3, AADC, TH, and D2R also demonstrated no difference between WT and PKO cells (Fig. 1C). Fig. 1 Induction of dopaminergic neurons from wild-type (WT) and ...
Highly connected neurons, called hub cells, are thought to contribute to certain forms of epilepsy and have also been shown to orchestrate synchrony in the hippocampus of developing rats. How hub cells are capable of hijacking networks to synchrony is not well understood. We hypothesize that the excitability type of hub cells may be an important factor. In general, neuronal excitability (which characterizes how neurons respond to input) falls into two categories, Type I and Type II, with networks of only Type II neurons synchronizing very well, and networks of only Type I neurons synchronizing rather poorly. We used computer simulations to investigate the synchronization properties of networks with a mixture of Type I and Type II neurons. We were particularly interested in the effect of placing Type II neurons as hub cells in the network. The results of these simulations show that relatively few Type II neurons are capable of hijacking the network to synchrony when they are placed as hub cells, ...
To : All First of all I would like to thank you all who answered my first question about examples of sensory neurones who have cell body located close to the stimulus ? The answers were as follows : PHOTORECEPTORS, COCHLEAR HAIR CELL, STRECH RECEPTORS, OLFACTORY RECEPTORS, GUASTATORY RECEPTORS. I looked up the sensors and found that all of them responds in a linear fashion to a increase in stimulus. However, in the enteric nervous system several authors say that the AH neurones are the sensory neurones. The AH neurone is characterized by having a prolonged after- hyperpolarization (,4 seconds) following an action potential, which is caused by opening of calcium activated potassium channels. I have always wondered why a sensory neurone would behave with such a strange pattern. The neurone is complete inactive during the after- hyperpolarization, so it is not really a matter of adaptation, but more a question of making the neurone completely inactive. The AH neurones are possibly coupled to a ...
The medial amygdala (MeA) is a central node in the interwoven circuits that regulate social behavior based on pheromones. Aromatase-expressing (arom+) neurons in the MeA are key for the establishment and maintenance of sex differences. Here, we characterized the intrinsic electrophysiological properties of arom+ neurons and non-aromatase (arom-) neurons in the MeA of male and female mice. Most electrophysiological properties were similar for arom+ neurons in the MeA between sexes, but the relative refractory period was twice as large in female mice. We also show that the firing pattern and firing frequency is markedly different between arom+ and arom- neurons. The activity of MeA neurons could be modulated by estradiol, which reduced activity in arom+ neurons in males. The differences between arom+ and arom- neurons were observed in both sexes suggesting that aromatase expression delineates a neural population in the MeA with similar and unique electrophysiological properties.
Finally, our article on human and mouse neurons has been published! The picture above shows the neurons of a human and a mouse. Human and mouse neurons are similar overall, but they also have…
A major challenge confronting the developing embryo is that of generating the appropriate numbers and distinct classes of neurons essential for constructing functional neuronal circuits. This involves tight coordination between proliferation, specification and differentiation during the course of neurogenesis. The developing spinal cord is a pertinent model with which to dissect the crosstalk that exists between these different programs, because we have a good understanding of the molecular mechanisms governing spinal neurons specification and differentiation (Dessaud et al., 2008).. The spinal cord develops from a caudal stem zone containing a pool of undifferentiated neural progenitors performing only proliferative divisions, one progenitor generating two daughter progenitor cells (PP) (Akai et al., 2005). Neural progenitors exiting the stem zone to contribute to the formation of the neural tube become subjected to morphogens, including Sonic hedgehog (Shh), which controls their specification, ...
It has been 10+ years since Gould et al. and Kempermann et al. showed that learning and enriched environments can enhance the survival of new neurons. These findings are logical precursors to the current study since, if these new neurons have all the necessary components, they suggest experience could add to the mnemonic functions of the hippocampus. But subsequent studies indicated that experience could also decrease the survival of new neurons. So perhaps structural changes to new neurons that are more relevant to learning might be worth investigating. For example, in many of my own experiments, I have failed to observe learning-induced changes in the number of new neurons but, if the number of dendrites or spines is increased, then there could still be an enhanced ability to process information. Or there could be the removal of some spines and the formation of others, suggesting a transformation in the type of information processed by new neurons. To get at these possibilities, Tronel et al. ...
The brain has evolved adaptive mechanisms for coping with stress and responds to stressors in highly stereotyped ways. One of the major physiological responses to stressful stimuli, the secretion of pituitary and adrenal hormones, is controlled by corticotropin-releasing hormone (CRH)-expressing neurons located in the paraventricular nucleus of the hypothalamus (PVH). CRH neuroendocrine neurons constitute the primary control center in the brain for initiating hormonal responses to stress, and the control of these neurons by other parts of the brain has been the subject of intensive investigation. One of the most massive sources of input to these neurons is the collection of axonal inputs originating from subpopulations of catecholaminergic (CA) neurons located in the hindbrain. These CA neurons are critical regulators of the mammalian stress axis, releasing the neurotransmitters epinephrine, norepinephrine and other co-localized peptide hormones (such as neuropeptide Y) onto CRH neuroendocrine ...
The neurotransmitter 5-hydroxytryptamine (5-HT, serotonin) mediates important brain functions and contributes to the pathophysiology and successful drug treatment of many common psychiatric disorders, especially depression. It is established that a key mechanism involved in the control of 5-HT neurones is feedback inhibition by presynaptic 5-HT autoreceptors, which are located on 5-HT cell bodies and nerve terminals. However, recent experiments have discovered an unexpected complexity of 5-HT neurone control, specifically in the form of postsynaptic 5-HT feedback mechanisms. These mechanisms have the physiological effects of 5-HT autoreceptors but use additional 5-HT receptor subtypes and operate through neural inputs to 5-HT neurones. A postsynaptic feedback system that excites 5-HT neurones has also been reported. This article discusses current knowledge of the pharmacology and physiology of these new found 5-HT feedback mechanisms and considers their possible contribution to depression
The neurotransmitter 5-hydroxytryptamine (5-HT, serotonin) mediates important brain functions and contributes to the pathophysiology and successful drug treatment of many common psychiatric disorders, especially depression. It is established that a key mechanism involved in the control of 5-HT neurones is feedback inhibition by presynaptic 5-HT autoreceptors, which are located on 5-HT cell bodies and nerve terminals. However, recent experiments have discovered an unexpected complexity of 5-HT neurone control, specifically in the form of postsynaptic 5-HT feedback mechanisms. These mechanisms have the physiological effects of 5-HT autoreceptors but use additional 5-HT receptor subtypes and operate through neural inputs to 5-HT neurones. A postsynaptic feedback system that excites 5-HT neurones has also been reported. This article discusses current knowledge of the pharmacology and physiology of these new found 5-HT feedback mechanisms and considers their possible contribution to depression
It has long been a dogma of neuroscience that the human brain is born with all the neurons it will ever have, and that those neurons must endure for a lifetime. But evidence has been accumulating that this dogma may not strictly be true. Neurons in the hippocampus and cerebellum, for example, differentiate through the first several years of childhood. In other species, such as mice and marmoset monkeys, new neuron growth has been found in adults. And neuronal progenitor cells have been discovered in adult human brains, although it was not known whether these stem cells normally divide into neurons. It now appears that they do, according to a study appearing in the November 1 issue of Nature Medicine by Peter S. Eriksson et al. The study involved terminal cancer patients who had been administered a diagnostic agent, BrdU (bromodeoxyuridine), that labels dividing cells. Upon the patients death, their brains were examined for the presence of BrdU. All of the patients showed evidence of recent ...
Oxygen glucose deprivation (OGD)/re-oxygenation (OGDR) induces profound oxidative injury and neuronal cell death. It mimics ischemia-reperfusion neuronal injury. CPI-1189 is a novel tumor necrosis factor alpha-inhibiting compound with potential neuroprotective function. Here in SH-SY5Y neuronal cells and primary murine cortical neurons, CPI-1189 pretreatment potently inhibited OGDR-induced viability reduction and cell death. In OGDR-stimulated neuronal cells, p38 phosphorylation was blocked by CPI-1189. In addition, CPI-1189 alleviated OGDR-induced reactive oxygen species production, lipid peroxidation, and glutathione consumption. OGDR-induced neuronal cell apoptosis was also inhibited by CPI-1189 pretreatment. Furthermore, in SH-SY5Y cells and cortical neurons, CPI-1189 alleviated OGDR-induced programmed necrosis by inhibiting mitochondrial p53-cyclophilin D-adenine nucleotide translocase 1 association, mitochondrial depolarization, and lactate dehydrogenase release to the medium. In summary, CPI-1189
We thank the reviewers for their thorough review. We have considered all of the comments, and in response have performed additional analyses, and have edited the text of the document to address each of the critiques. Below we respond in a point-by-point manner to each comments, our responses are in bold.. Synthesis Statement for Author (Required): SYNTHESIS. In this manuscript, the authors review the analysis of MEA data performed in previously published works and discuss the best ways to analyze MEA recordings. The authors discuss several important limitations of the MEA approach and they offer information and guidelines on ways to address these limitations. This information will be important to share with the broader neuroscience community and with scientists who. are interested in beginning to work with MEAs in particular. However, the reviewers also identified several concerns that need to be addressed.. 1) Neuronal density and array density seem to be two key variables that should greatly ...
The metazoan gut performs multiple physiologic functions, including digestion and absorption of nutrients, and also serves as a physical and chemical barrier against ingested pathogens and abrasive particles. Maintenance of these functions and structures is partly controlled by the nervous system, yet the precise roles and mechanisms of the neural control of gut integrity remain to be clarified in Drosophila. Here we screened for GAL4 enhancer-trap strains and labeled specific subsets of neurons. To inhibit their neuronal activity, we used Kir2.1. We identified an NP3253 line that is susceptible to oral infection by Gram-negative bacteria. The subset of neurons driven by the NP3253 line includes some of the enteric neurons innervating the anterior midgut, and these flies have a disorganized proventricular structure with high permeability of the peritrophic matrix and epithelial barrier. The findings of the present study indicate that neural control is crucial for maintaining the barrier function ...
The Neuron model simulates the membrane potentials in vertebrate neurons, which are modeled as three serially connected compartments: dendrite, soma, and axon. The model is designed to simulate the dynamic properties of neurons including electrotonic spread between neuronal compartments (dendrite, soma, and axon).
The word mosaic conjures up images of colorful tiles artfully arranged. For neurobiologists, the word may invoke the genetic hodgepodge that is the human brain. In the November 1 Science, researchers led by Fred Gage at the Salk Institute for Biological Studies, La Jolla, California, report that the genetic makeup of our most vaunted organ is actually a mosaic of genetically distinct neurons. They found scads of genomic changes in single cells from individual brains. Neurons with different genomes are bound to have different phenotypes, though what this means for the health of the brain is unclear.. The scientists had previously found that neurons can lose or duplicate entire chromosomes and that small retrotransposons frequently copy and paste themselves within the genome of a given brain cell (see Rehen et al., 2005, Jun 2005 news story on Muotri et al., 2005). First author Michael McConnell, now at the University of Virginia in Charlottesville, and colleagues characterize copy number ...
TY - BOOK. T1 - Neural Regeneration. AU - So, Kwok Fai. AU - Xu, Xiao Ming. PY - 2015/2/6. Y1 - 2015/2/6. N2 - Neural Regeneration provides an overview of cutting-edge knowledge on a broad spectrum of neural regeneration, including: Neural regeneration in lower vertebrates Neural regeneration in the peripheral nervous system Neural regeneration in the central nervous system Transplantation-mediated neural regeneration Clinical and translational research on neural regeneration The contributors to this book are experts in their fields and work at distinguished institutions in the United States, Canada, Australia, and China. Nervous system injuries, including peripheral nerve injuries, brain and spinal cord injuries, and stroke affect millions of people worldwide every year. As a result of this high incidence of neurological injuries, neural regeneration and repair is becoming a rapidly growing field dedicated to the new discoveries to promote structural and functional recoveries based on neural ...
TY - JOUR. T1 - The Effects of Sindbis Viral Vectors on Neuronal Function. AU - Uyaniker, Seçil. AU - van der Spek, Sophie J.F.. AU - Reinders, Niels R.. AU - Xiong, Hui. AU - Li, Ka Wan. AU - Bossers, Koen. AU - Smit, August B.. AU - Verhaagen, Joost. AU - Kessels, Helmut W.. PY - 2019/8/8. Y1 - 2019/8/8. N2 - Viral vectors are attractive tools to express genes in neurons. Transduction of neurons with a recombinant, replication-deficient Sindbis viral vector is a method of choice for studying the effects of short-term protein overexpression on neuronal function. However, to which extent Sindbis by itself may affect neurons is not fully understood. We assessed effects of neuronal transduction with a Sindbis viral vector on the transcriptome and proteome in organotypic hippocampal slice cultures, and analyzed the electrophysiological properties of individual CA1 neurons, at 24 h and 72 h after viral vector injection. Whereas Sindbis caused substantial gene expression alterations, changes at the ...
In contrast, in neurons projecting to dopamine neurons, dendrites curved and coursed circuitously or turned inward toward the soma (Figure 6K). Furthermore, spines of inputs to GABAergic neurons were evenly. spaced and were of similar size. In contrast, inputs to dopamine neurons had uneven spines and varicosities, and their dendrites were irregular in contour (Figures 6D and 6H, inset). These results suggest that, whereas neurons projecting to GABAergic neurons are click here consistent with typical medium spiny neurons, neurons projecting to dopaminergic neurons have significantly different morphologies. We make two conclusions from these data: First, striatal neurons do project monosynaptically to dopamine neurons; and second, our technique is capable of revealing exquisite, cell-type-specific connectivity. Whereas SNc dopamine neurons receive the most input from the DS, VTA dopamine Buparlisib neurons receive the most input from the Acb (Figure 3). Although heterogeneity of the Acb was ...
Neurons in the gracile nucleus of the camel brain stem were studied by Golgi method. Neurons were classified based on soma size and shape, density of dendritic tree, morphology and distribution of appendages. Six types of neurons were identified. Type I neurons had very large somata with appendages on their somata and distal dendrites. Type II neurons had large somata and almost smooth dendrites. Type III neurons displayed medium size somata with dendritic appendages of different forms. Type IV neurons were small to medium spheroidal or triangular neurons. Somata and dendrites of these neurons had appendages of different forms. Type V medium-size neurons had bipolar, round or fusiform somata and poorly branching dendritic tree. Some spines and appendages were seen on somata and dendrites of these neurons. Neurons of type VI were medium-size unipolar, round or fusiform with spines on their dendrites. The radiating branching pattern was more common than the tufted for all types of neurons. Wide overlap
TY - JOUR. T1 - Multi-neuron action potentials recorded with tetrode are not instantaneous mixtures of single neuronal action potentials.. AU - Shiraishi, Yasushi. AU - Katayama, Norihiro. AU - Takahashi, Tetsuya. AU - Karashima, Akihiro. AU - Nakao, Mitsuyuki. PY - 2009. Y1 - 2009. N2 - Multiunit recording with multi-site electrodes in the brain has been widely used in neuroscience studies. After the data recording, neuronal spikes should be sorted according to the pattern of spike waveforms. For the spike sorting, independent component analysis (ICA) has recently been used because ICA has potential for resolving the problem to separate the overlapped multiple neuronal spikes. However the performance of spike sorting by using ICA has not been examined in detail. In this study, we quantitatively evaluate the performance of ICA-based spike sorting method by using simulated multiunit signals. The simulated multiunit signal is constructed by compositing real extracellular action potentials recorded ...
In sensory systems, peripheral organs convey sensory inputs to relay networks where information is shaped by local microcircuits before being transmitted to cortical areas. In the olfactory system, odorants evoke specific patterns of sensory neuron activity that are transmitted to output neurons in olfactory bulb (OB) glomeruli. How sensory information is transferred and shaped at this level remains still unclear. Here we employ mouse genetics, 2-photon microscopy, electrophysiology and optogenetics, to identify a novel population of glutamatergic neurons (VGLUT3+) in the glomerular layer of the adult mouse OB as well as several of their synaptic targets. Both peripheral and serotoninergic inputs control VGLUT3+ neurons firing. Furthermore, we show that VGLUT3+ neuron photostimulation in vivo strongly suppresses both spontaneous and odour-evoked firing of bulbar output neurons. In conclusion, we identify and characterize here a microcircuit controlling the transfer of sensory information at an early
The mammalian brain maintains few developmental niches where neurogenesis persists into adulthood. One niche is located in the olfactory system where the olfactory bulb continuously receives functional interneurons. In vivo two-photon microscopy of lentivirus-labeled newborn neurons was used to directly image their development and maintenance in the olfactory bulb. Time-lapse imaging of newborn neurons over several days showed that dendritic formation is highly dynamic with distinct differences between spiny neurons and non-spiny neurons. Once incorporated into the network, adult-born neurons maintain significant levels of structural dynamics. This structural plasticity is local, cumulative and sustained in neurons several months after their integration. Thus, I provide a new experimental system for directly studying the pool of regenerating neurons in the intact mammalian brain and suggest that regenerating neurons form a cellular substrate for continuous wiring plasticity in the olfactory bulb.
TY - JOUR. T1 - Biochemical changes associated with selective neuronal death following short-term cerebral ischaemia. AU - Sims, Neil R.. AU - Zaidan, Emad. N1 - Copyright: Copyright 2015 Elsevier B.V., All rights reserved.. PY - 1995/6. Y1 - 1995/6. N2 - A brief interruption of blood flow to the brain results in the selective loss of specific subpopulations of neurons. Important advances have been made in recent years in defining the biochemical changes associated with cerebral ischaemia and reperfusion and in identifying physical and chemical interventions capable of modifying the extent of neuronal loss. Neuronal death is not irreversibly determined by the ischaemic period but develops during recirculation over a period of hours or even days in different susceptible neuronal populations. The onset of ischaemia produces a rapid decline in ATP production and an associated major redistribution of ions across the plasma membrane including a large intracellular accumulation of Ca2+ in many ...
TY - JOUR. T1 - Synaptic potentials in rat locus coeruleus neurones. AU - Cherubini, E.. AU - North, R. A.. AU - Williams, John. PY - 1988. Y1 - 1988. N2 - 1. Intracellular recordings were made from locus coeruleus neurones in a slice of tissue cut from the rat pons. A depolarizing postsynaptic potential (PSP) followed electrical stimulation of the slice surface; the latency was 1-3 ms and the duration was 50-200 ms. 2. The reversal potential of the PSP (estimated by extrapolation from potentials between -60 and -90 mV) was -27 mV when the recording electrodes contained potassium chloride, and -36 mV when electrodes contained potassium acetate or methylsulphate. 3. Kynurenic acid depressed the PSP amplitude by up to 60%. The residual PSP reversed polarity at -50 mV (extrapolated, potassium chloride in electrodes) or -70 mV (observed, potassium methylsulphate in electrodes): it was blocked by bicuculline (10 μM). 4. Exogenously applied γ-aminobutyric acid (GABA) depolarized cells when the ...
TY - JOUR. T1 - Dynamic firing properties of type I spiral ganglion neurons. AU - Davis, Robin. AU - Crozier, Robert A.. PY - 2015/7/2. Y1 - 2015/7/2. N2 - Spiral ganglion neurons, the first neural element in the auditory system, possess complex intrinsic properties, possibly required to process frequency-specific sensory input that is integrated with extensive efferent regulation. Together with their tonotopically-graded sizes, the somata of these neurons reveal a sophisticated electrophysiological profile. Type I neurons, which make up ~95 % of the ganglion, have myriad voltage-gated ion channels that not only vary along the frequency contour of the cochlea, but also can be modulated by regulators such as voltage, calcium, and second messengers. The resultant developmentally- and tonotopically-regulated neuronal firing patterns conform to three distinct response modes (unitary, rapid, and slow) based on threshold and accommodation. This phenotype, however, is not static for any individual type ...
TY - JOUR. T1 - Excitation of rat locus coeruleus neurons by adenosine 5′-triphosphate. T2 - Ionic mechanism and receptor characterization. AU - Shen, Ke-Zhong. AU - North, R. A.. PY - 1993. Y1 - 1993. N2 - ATP and several congeners were applied to locus coeruleus neurons in slices cut from rat pons. Whole-cell recording of membrane current showed that ATP caused an inward current at -60 mV. Effective concentrations (applied by superfusion) were 3-300 μM, and the peak current was about 150 pA at -60 mV. 2-Methylthioadenosine 5′-triphosphate was slightly more potent than ATP, adenosine 5′-diphosphate was about equipotent with ATP, α,β-methylene adenosine 5′-triphosphate was slightly less potent than ATP, and β,γ′-methylene adenosine 5′-triphosphate and adenosine 5′-monophosphate had little or no effect. Adenosine (100 μM) caused small outward currents (40 pA). By changing the ionic composition of the pipette and extracellular solution, it was shown that the inward current ...
TY - JOUR. T1 - Alpha1-adrenoceptor-mediated excitation of substantia nigra pars reticulata neurons. AU - Berretta, N.. AU - Bernardi, G.. AU - Mercuri, N. B.. PY - 2000/6. Y1 - 2000/6. N2 - The effect of noradrenaline was studied in principal neurons of the substantia nigra pars reticulata in rat brain slices using patch clamp recordings. Perfusion of noradrenaline or the α1-adrenoceptor agonist phenylephrine increased the spontaneous firing activity of reticulata cells. The α1-adrenoceptor antagonist prazosin counteracted the effects of noradrenaline. In contrast, the β-adrenoceptor agonist isoproterenol did not affect the activity of reticulata cells and the β-adrenoceptor antagonist pindolol did not prevent noradrenalines effect. In whole-cell recordings, at -60 mV holding potential, noradrenaline caused a tetrodotoxin-resistant inward current with a time-course similar to the increase in firing activity. Analysis of the reversal potential of this current did not give homogeneous ...
Anatomic imaging of patients with chronic well-treated hypertension has demonstrated dilatation of the lateral cerebral ventricles and left brain atrophy, whereas positron emission tomography has shown only subtle reductions in regional cerebral metabolic rates for glucose in some subcortical nuclei. To further explore the implications of the imaging changes, an analytic technique designed to determine functional neuronal connectivity between regions of interest (ROIs) was applied to the data on regional cerebral metabolic rates for glucose to determine if and where in the brain reduction of functional neuronal connectivity occurred.. Glucose metabolism was measured by positron emission tomography in 17 older men (age, 68 +/- 8 years) with well-controlled, noncomplicated hypertension of at least 10 years duration and in 25 age- and sex-matched healthy control subjects. A significant correlation difference analysis was performed to determine which ROI pairs had reduced correlation coefficients ...
The production of ferret visual cortical neurons was studied using 3H- thymidine autoradiography. The genesis of cortical neurons begins on or slightly before embryonic day 20 (E20) of the 41 d gestational period, continues postnatally until 2 weeks after birth (P14), and follows an inside-out radial gradient with neurons for the deeper cortical layers being generated before those for the superficial layers. Layer I neurons are generated both early (E20-E30) and late (P1-P14) in the period of cortical neurogenesis and, thus, provide at least a partial exception to the inside-out gradient of cortical neurogenesis. Tangential gradients of cortical neurogenesis extend across areas 17 and 18 in both the anterior-to-posterior and lateral-to-medial directions. Neither of these gradients bears a meaningful relationship to the cortical representation of the visual field. Most infragranular and granular layer neurons are generated prenatally, while most supragranular layer neurons are produced ...
TY - JOUR. T1 - Glucocorticoids enhance the excitability of principal basolateral amygdala neurons. AU - Duvarci, Sevil. AU - Paré, Denis. PY - 2007/4/18. Y1 - 2007/4/18. N2 - A large body of pharmaco-behavioral data implicates the basolateral nucleus of the amygdala (BLA) in the facilitation of memory consolidation by emotions. Overall, this evidence suggests that stress hormones released during emotional arousal increase the activity of BLA neurons. In turn, this increased BLA activity would facilitate synaptic plasticity elsewhere in the brain, to which the BLA projects. However, the direct effects of glucocorticoids on BLA neurons are incompletely understood. In the present study, we examined the direct effects of corticosterone (CORT) on principal neurons of the rat BLA in vitro using whole-cell patch-clamp recordings. We found that application of a stress level of CORT for 20 min caused significant changes in the passive properties and responsiveness of BLA cells measured 1-2 h later. ...
Hello everyone, I have a question about neuronal cell cultures, and although I know we are a group who work primarily with tissues, sometimes these types of questions come to my lab and I am intrigued enough to try to find an answer. And I though I would consult with my fellow histonetters to see if any of you have any suggestions. An investigator who works with neuronal cell cultures has fixed them with 3.5% paraformaldehyde in 1xPBS solution with success, twice. Then the third time he saw blebbing on the cell membranes, and after consulting with our confocal microscopy expert, he changed to 4% paraformaldehyde (in, I believe, the same buffer) and had the same results. It turns out our expert has had the same problem with seemingly healthy cells that develop the blebbing upon fixation. My first instinct was that he needs to adjust the osmolarity of the solutions. Then I fell back to my electron microscopy experience and thought he may need to use a different fixative/buffering system, such as ...
Vagal projecting (VP) neurons were localized by intraneural injections of fluorescent dyes or cholera toxin conjugated horseradish peroxidase (CT-HRP) or by intraperitoneal injection of fluorescent dyes. Spinal projecting (SP) neurons were localized by injecting CT-HRP or contrasting dyes into the C4/C5 cord segments. No doubly labelled neurons were seen in the three nuclei known to project to both vagus nerve and spinal cord, viz., dorsal nucleus of the vagus (DNV), nucleus ambiguous complex (NAc) and the intermediate region (NI) between DNV and NAc. VP and SP neurons intermingled in the caudal parts of the NAc and DNV. In the middle part of the NAc, VP neurons congregated mostly dorsal to the SP neurons. In the rostral extremity of the NAc, SP neurons were rarely encountered. No SP neurons were seen in the rostral end of the DNV. In contradistinction to the few VP neurons in the NI, there were many SP neurons in this region. The ratios of VP to SP neurons in DNV were on the average 20 to 1 and ...
BioAssay record AID 349212 submitted by ChEMBL: Activity at RYR2 receptor in rat cerebellar granule neurons assessed activation of [45Ca2+] uptake at 20 uM after 10 mins.
In severe cases of sensorineural hearing loss where the numbers of auditory neurons are significantly depleted, stem cell-derived neurons may provide a potential source of replacement cells. The success of such a therapy relies upon producing a population of functional neurons from stem cells, to enable precise encoding of sound information to the brainstem. Using our established differentiation assay to produce sensory neurons from human stem cells, patch-clamp recordings indicated that all neurons examined generated action potentials and displayed both transient sodium and sustained potassium currents. Stem cell-derived neurons reliably entrained to stimuli up to 20 pulses per second (pps), with 50% entrainment at 50 pps. A comparison with cultured primary auditory neurons indicated similar firing precision during low-frequency stimuli, but significant differences after 50 pps due to differences in action potential latency and width. The firing properties of stem cell-derived neurons were also
The distribution of serotonin (5HT-ir), FMRF amide (FMRF a-ir), catch-relaxing-peptide (CARP-ir), dopamine (DA-ir), gamma-amino-butyric-acid (GABA-ir), and leucokinin (LK-ir) immunoreactive neurons were compared in the ganglia of Helix CNS. These neurons are not distributed randomly, but their location outlines distinct groups in the ganglia. In a few groups only DA-ir, GABA-ir and LK-ir neurons can be seen, whereas in the majority of groups FMRFa-ir, CARP-ir and 5HT-ir neurons are localized together. In the latter groups of immunoreactive neurons either FMRFa- and CARP- or 5HT- and FMRFa-immunoreactivities coexist in numerous neurons. Immunoreactive groups composed of DA-ir, GABA-ir and LK-ir neurons are localized exclusively in the areas of the origin of skin nerves, suggesting that these neurons are related to the processing of cutaneous afferent information. Other groups constituted by 5HT-ir, FMRFa-ir and CARP-ir neurons are localized first of all in ganglia the neurons of which innervate large
Abstract: The size and extent of folding of the mammalian cerebral cortex are important factors that influence a species cognitive abilities and sensorimotor skills. Studies in various animal models and in humans have provided insight into the mechanisms that regulate cortical growth and folding. Both protein-coding genes and microRNAs control cortical size, and recent progress in characterizing basal progenitor cells and the genes that regulate their proliferation has contributed to our understanding of cortical folding. Neurological disorders linked to disruptions in cortical growth and folding have been associated with novel neurogenetic mechanisms and aberrant signalling pathways, and these findings have changed concepts of brain evolution and may lead to new medical treatments for certain disorders.. ...
Recently some studies demonstrate that adult neuronal genome is a genetic mosaic but the role of this mosaicism and how is generated are not well known. The two main mechanisms that could result in the neuronal mosaic genome are somatic recombination and the LINE-1 (L1) retrotransposition. Some evidences, alterations in central nervous system development found in knock-out (KO) mice for proteins related with DNA repair processes and L1 activation in neuronal precursors, suggest that neuronal genome mosaicism may be related with the generation of neuronal diversity during central nervous system development. However, if genome reorganization processes happen in the adult nervous system during neuronal plasticity events are not established. Recently, it has been reported that neuronal activity transiently provokes increase of neuronal DNA breaks in cerebral areas where long-term neuronal plasticity events takes place, in some case related with cognition. DNA breaks have been related with the ...
TY - JOUR. T1 - Analysis of message expression in single neurons of Alzheimers disease brain. AU - Callahan, L. M.. AU - Chow, N.. AU - Cheetham, J. E.. AU - Cox, Christopher. AU - Coleman, P. D.. PY - 1998/1. Y1 - 1998/1. N2 - Because many cell types and disease states exist in the sample of cells in even a very small region of Alzheimers disease (AD) brain tissue, optimal understanding of disease mechanisms requires study at the level of the single cell. Our Golgi studies of single neurons in the AD brain have revealed reduced dendritic extent in many but not all, brain regions. This reduced dendritic extent is interpreted as reduced capacity of neurons in AD to proliferate new dendritic material. Studies of message expression in single neurons reveal that neurons containing neurofibrillary tangles (NFTs) show reduced expression of messages for proteins related to growth of neuronal processes and to synapses. Neighboring neurons free of NFTs express these messages at levels approximating the ...
In this paper, we demonstrate for the first time an ultrafast fully functional photonic spiking neuron. Our experimental setup constitutes a complete all-optical implementation of a leaky integrate-and-fire neuron, a computational primitive that provides a basis for general purpose analog optical computation. Unlike purely analog computational models, spiking operation eliminates noise accumulation and results in robust and efficient processing. Operating at gigahertz speed, which corresponds to at least 108 speed-up compared with biological neurons, the demonstrated neuron provides all functionality required by the spiking neuron model. The two demonstrated prototypes and a demonstrated feedback operation mode prove the feasibility and stability of our approach and show the obtained performance characteristics.. © 2011 Optical Society of America. Full Article , PDF Article ...
TY - JOUR. T1 - Dyrk1A phosphorylates p53 and inhibits proliferation of embryonic neuronal cells. AU - Park, Joongkyu. AU - Oh, Yohan. AU - Yoo, Lang. AU - Jung, Min Su. AU - Song, Woo Joo. AU - Lee, Sang Hun. AU - Seo, Hyemyung. AU - Chung, Kwang Chul. N1 - Copyright: Copyright 2015 Elsevier B.V., All rights reserved.. PY - 2010/10/8. Y1 - 2010/10/8. N2 - Down syndrome (DS) is associated with many neural defects, including reduced brain size and impaired neuronal proliferation, highly contributing to the mental retardation. Those typical characteristics of DS are closely associated with a specific gene group Down syndrome critical region (DSCR) on human chromosome 21. Here we investigated the molecular mechanisms underlying impaired neuronal proliferation in DS and, more specifically, a regulatory role for dual-specificity tyrosine-(Y) phosphorylation-regulated kinase 1A (Dyrk1A), a DSCR gene product, in embryonic neuronal cell proliferation. We found that Dyrk1A phosphorylates p53 at Ser-15 ...
Programmed cell death is a prominent feature of embryonic development and is essential in matching the number of neurons to the target tissues that are innervated. Although a decrease in neuronal number which coincides with peripheral synaptogenesis has been well documented in the avian ciliary ganglion, it has not been clear whether cell death also occurs earlier. We observed TUNEL-positive neurons as early as stage 24, with a large peak at stage 29. This cell death at stage 29 was followed by a statistically significant (P < 0.0001) decrease in total neuron number at stage 31. The total number of neurons was recovered by stage 33/34. This suggested that dying neurons were replaced by new neurons. This replacement process did not involve proliferation because bromodeoxyuridine applied at stages 29 and 31 was unable to label neurons harvested at stage 33/34. The peak of cell death at stage 29 was increased 2.3-fold by removal of the optic vesicle and was reduced by 50% when chCNTF was ...
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Given that neurons operate by means of signal transmission and not on distinctive slow or fast timescales, Im assuming that you are looking for abstract models of neurons that are more realistic than the time-independent artificial representations most often used in neural networks, but correct me if Im wrong.. There are neuron models that attempt to mimic the biological processes of the neuron, and there are also abstract models of neurons that attempt to work in imperfect or specific conditions (i.e. in response to individual neurotransmitters, as demonstrated during synaptic transmission). These models usually take into account the action potentials (spikes) and refractory periods of real neurons, and thus these models are also known as spiking neuron models.. Here is one model of a spiking neuron, which attempts to imitate authentic spiking as observed in cortical neurons. This model incorporates Hodgkin-Huxley-type-dynamics with integrate-and-fire-type properties. ...
SIMULTANEOUS INTRACELLULAR-RECORDINGS FROM ENTERIC NEURONS REVEAL THAT MYENTERIC AH NEURONS TRANSMIT VIA SLOW EXCITATORY POSTSYNAPTIC POTENTIALS Journal Articles ...
Translocator protein (TSPO) imaging can be used to detect neuroinflammation (including microglial activation) after acute cerebral infarction. However, longitudinal changes of TSPO binding after mild ischemia that induces selective neuronal loss (SNL) without acute infarction are not well understood. Here, we performed TSPO imaging with [18F]DPA-714 to determine the time course of neuroinflammation and SNL after mild focal ischemia. Mild focal ischemia was induced by middle cerebral artery occlusion (MCAO) for 20 min. In MCAO rats without acute infarction investigated by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, in vitro ARG revealed a significant increase of [18F]DPA-714 binding in the ipsilateral striatum compared with that in the contralateral side at 1, 2, 3, and 7 days after MCAO. Increased [18F]DPA-714 binding was observed in the cerebral cortex penumbra, reaching maximal values at 7 days after MCAO. Activation of striatal microglia and astrocytes was observed with immunohistochemistry
TY - JOUR. T1 - Aging and mammalian cerebral cortex. T2 - Monkeys to humans. AU - Morrison, John. PY - 2003/4/1. Y1 - 2003/4/1. UR - http://www.scopus.com/inward/record.url?scp=0038647799&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0038647799&partnerID=8YFLogxK. M3 - Article. C2 - 12813209. AN - SCOPUS:0038647799. VL - 17. JO - Alzheimer Disease and Associated Disorders. JF - Alzheimer Disease and Associated Disorders. SN - 0893-0341. IS - SUPPL. 2. ER - ...
Also, their analysis revealed that the axonal branching of rosehip neurons was more robust than any other type of cell observed in this brain region, with the volume of axonal terminations, or boutons, measuring four times larger than NGFC boutons.. Furthermore, the researchers say that the rosehip neuron has a molecular marker signature of (GAD1+CCK+, CNR1-SST-CALB2-PVALB-), a signature not seen in the mouse cortex.. According to the paper, the researchers still have much to learn about the function of rosehip neurons in the human brain. Because they observed rosehip neurons connecting to their partner neurons - pyramidal neurons, in very specific places, they hypothesize that rosehip neurons might be controlling the flow of information in a distinctive way.. One next step will be to see if postmortem brains from patients with neuropsychiatric disorders display rosehip neurons with alterations, to begin investigating whether or not these newly discovered cells play a role in mental ...
The goal of this study was to understand the spontaneous neuronal activities and acoustic responses of neurons in the primary auditory cortex (AI), and the modulation of different divisions of the medial geniculate body (MGB) on different layers of the auditory cortex (AC) especially AI, through in vivo intracellular recordings and/or extracellular recordings in adult urethane-anesthetized guinea pigs. One hundred and eighty nine neurons/units in AC, distributed among all six cortical layers, were recorded intracellularly and/or extrcellularly. Thirty-one of forty intracellular recorded neurons (77.50 %) and one hundred and thirty of one hundred and forty nine extracellular recorded units (87.25%) showed excitatory responses to a noise burst stimulus applied to the contralateral ear of the animals. The extracellularly recorded neurons showed synchronized spikes with the excitatory postsynaptic potential (EPSP), action potential (AP) and/or rhythmic oscillation of the intracellularly recorded ...
In order for the axon to initiate an action potential, we know that the axon initial segment must be brought to threshold. So my question is as follows: Say we have the minimum charge input, X, necessary to depolarize the axon initial segment of Neuron 1. Now, we have Neuron 2, which has a larger soma. Will this same input X be sufficient to depolarize the axon initial segment of Neuron 2?. I am trying to explore how physical concepts like capacitance manifest in biological systems. Neuron 1s soma (approximated as a sphere) presumably has a lower capacitance than Neuron 2s soma (approximated as a sphere), due to the difference in cross sectional area of the somas. Therefore, I would assume that Neuron 2s axon initial segment requires greater input to depolarize than Neuron 1s axon initial segment.. Is this simplistic idealization of somas actually observed in experiments? ...
Expression of the neuronal marker NeuN and satellite glial cell markers GFAP and S-100 in primary rhesus DRG cultures. Primary rhesus DRG cultures showing a mat
Problem statement: It has been well documented that drugs of abuse such as cocaine can cause enhanced progression of HIV-Associated Neuropathological Disorders (HAND), the underlying mechanisms mediating these effects remain poorly understood. Approach: In present study, we explored the impact of cocaine exposure (I and 10 μM) on the dendritic beading in rat primary hippocampal neurons. Using the approach of transfection with green fluorescent protein, we observed significant dendritic swelling in hippocampal neurons exposed to 10 μM but not 1 μM of cocaine when compared with the saline treated group. Results: Cocaine exposure also resulted in decreased expression of the synaptic plasticity gene, Arc as evidenced by Western blotting. Intriguingly, cocaine exposure of primary neurons in the presence of the neurotoxin-HIV envelope protein gp 120, resulted in increased enhancement of neuronal beading as compared with exposure of neurons to either agent alone. Conclusion: Taken together these
from neuron import h Warning: no DISPLAY environment variable. --No graphics will be displayed. NEURON -- Release 7.4 (1370:16a7055d4a86) 2015-11-09 Duke, Yale, and the BlueBrain Project -- Copyright 1984-2015 See http://www.neuron.yale.edu/neuron/credits Traceback (most recent call last): File ,stdin,, line 1, in ,module, File /home/lmedina/.local/lib64/python2.7/site-packages/neuron/__init__.py, line 479, in ,module, set_vec_as_numpy = nrn_dll_sym(nrnpy_set_vec_as_numpy) File /home/lmedina/.local/lib64/python2.7/site-packages/neuron/__init__.py, line 394, in nrn_dll_sym dll = nrn_dll() File /home/lmedina/.local/lib64/python2.7/site-packages/neuron/__init__.py, line 454, in nrn_dll raise Exception(unable to connect to the NEURON library) Exception: unable to connect to the NEURON library ,,, v=h.Vector() Traceback (most recent call last): File ,stdin,, line 1, in ,module, NameError: name h is not ...
In vitro whole-cell patch-clamp methods were used to examine the contribution of one component of intracollicular circuitry, the superficial gray layer, to the generation of bursts of action potentials that occur in the intermediate layer and that command head and eye movements in vivo. Applying a single brief (0.5 ms) pulse of current to the superficial layer of rat collicular slices evoked prolonged bursts of excitatory postsynaptic currents (EPSCs) in the cells of the intermediate layer. The EPSCs were sufficient to elicit bursts of action potentials that lasted as long as 300 ms and resembled presaccadic command bursts. To examine the contribution of neurons within the superficial layer to the production of these bursts, we determined how superficial neurons respond to the same current pulses that evoke bursts in the intermediate layer. Recordings from 61 superficial layer cells revealed 19 neurons that produced multiple action potentials following stimulation. Nine of these 19 neurons were ...
Intrinsic neuronal excitability has been reported to change during normal aging. The bed nucleus of the stria terminalis (BNST), a limbic forebrain structure, is involved in fear, stress and anxiety; behavioral features that exhibit age-dependent properties. To examine the effect of aging on intrinsic neuronal properties in BNST we compared patch clamp recordings from cohorts of female mice at two ages, 3-4 months (Young) and 29-30 months (Aged) focusing on 2 types of BNST neurons. Aged Type I neurons exhibited a hyperpolarized resting membrane potential (RMP) of circa -80 mV compared to circa -70 mV in the Young. A key finding in this study is a hyper-excitability of Type II neurons with age reflected in an increase in firing frequency in response to depolarizing current injections; activation of Type II neurons is believed to dampen anxiety like responses. Such age-related changes in intrinsic neurophysiological function are likely to modulate how the limbic system, acting via BNST, shapes ...
The consequences of ongoing neurogenesis have long been the subject of speculation. New neurons in the dentate gyrus of the hippocampus seem to be added throughout juvenile and adult life, suggesting that they do not replace neurons that die (36). Alternatively, work in the song-control system of birds has shown that neuronal replacement occurs in some nuclei, perhaps to play a role in song learning (37). Concerning olfaction, one possibility is that new interneurons are simply added to the bulbs, as they are in the hippocampus. Yet, although increases in the number of interneurons have been reported in the adult, substantial granule cell death has also been observed, suggesting that newly generated neurons may replace dying ones (38).. This ongoing recruitment of interneurons may also open new opportunities to investigate the cellular basis for olfactory processing and its functional plasticity. The presence of a pool of new neurons accompanied by the emergence of new synapses could play a role ...
Inhibitory neuronal activity is critical for the normal functioning of the brain, but is thought to go awry during neurological disorders such as epilepsy. Animal models have suggested both decreased and increased inhibition as possible initiators of epileptic activity, but it is not known if, or how, human inhibitory neurons shape seizures. Here, using large-scale recordings of neocortical single neurons in patients with secondarily generalized tonic-clonic seizures, we show that fast-spiking (FS) inhibitory activity first increases as a seizure spreads across the neocortex, impeding and altering the spatial flow of fast epileptic traveling waves. Unexpectedly, however, FS cells cease firing less than half-way through a seizure. We use biophysically-realistic computational models to show that this cessation is due to FS cells entering depolarization block as a result of extracellular potassium accumulation during the seizure and not because they are inhibited by other inhibitory subtypes. ...
The innate immune system plays a critical role in both the initial response to an invading pathogen, which frequently limits or contains pathogen replication and dissemination, and the induction of an effective adaptive immune response, which is most often the primary mechanism for pathogen clearance. The characteristics of the innate immune response are determined in part by the pathogen initiating the response but can also be influenced by the type of cell in which the response is generated. In this report, we examined the functional PRR-mediated pathways present in human neuronal cells and differentiated primary rat neurons, with a particular focus on those pathways previously identified as being important for antiviral innate immune responses in other cell types. We drew four main conclusions. First, human neuronal cells possess functional TLR3-, TLR4-, RIG-I-, and MDA5-mediated PRR pathways whose activity was maturation-dependent. Second, both extracellular and transfected poly(I-C) induced ...