Definition of Human thalamus in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is Human thalamus? Meaning of Human thalamus as a legal term. What does Human thalamus mean in law?
The general patterns of early thalamocortical development follow a similar sequence in all mammals. Thalamocortical projections descend through the ventral thalamus, advance in the internal capsule amongst cells which already possess dorsal thalamic projections, then reach the cerebral cortex by associating with subplate cells and their early corticofugal projections. Initially, the thalamic projections pause in the internal capsule and subplate layer. The interactions of the thalamocortical projections with the early generated, largely transient cells of the subplate, marginal zone, internal capsule and ventral thalamus are believed to play a crucial role in the organized deployment of thalamic projections and establishing a functional cortical architecture. Selective fasciculation, contact guidance and release of neurotrophic factors are thought to play roles in the development of thalamocortical projections. These ideas are obtaining support from recent work on reeler and other strains of mice. The
Thalamocortical (TC) fibers have been referred to as one of the two constituents of the isothalamus, the other being micro neurons. Thalamocortical fibers have a bush or tree-like appearance as they extend into the internal capsule and project to the layers of the cortex. The main thalamocortical fibers extend from different nuclei of the thalamus and project to the visual cortex, somatosensory (and associated sensori-motor) cortex, and the auditory cortex in the brain. Thalamocortical radiations also innervate the gustatory pathways, as well as pre-frontal motor areas. Visual input from the optic tract is processed by the lateral geniculate nucleus of the thalamus, auditory input in the medial geniculate nucleus, and somatosensory input in the ventral posterior nucleus of the thalamus. Thalamic nuclei project to cortical areas of distinct architectural organization and relay the processed information back to the area of original activity in the thalamus via corticothalamic (CT) fibers.[2] The ...
To elucidate the formation of early thalamocortical synapses we recorded optical images with voltage-sensitive dyes from the cerebral cortex of prenatal rats by selective thalamic stimulation of thalamocortical slice preparations. At embryonic day (E) 17, thalamic stimulation elicited excitation that rapidly propagated through the internal capsule to the cortex. These responses lasted less than 15 ms, and were not affected by the application of glutamate receptor antagonists, suggesting that they might reflect presynaptic fiber responses. At E18, long-lasting (more than 300 ms) responses appeared in the internal capsule and in subplate. By E19, long-lasting responses increased in the cortical subplate. By E21, shortly before birth, the deep cortical layers were also activated in addition to the subplate. These long-lasting responses seen in the internal capsule and subplate were blocked by the antagonist perfusion, but the first spike-like responses still remained. The laminar location of the responses
article{MaScClMo07, author = {J{o}rg Mayer and Heinz Georg Schuster and Jens Christian Claussen and Matthias M{o}lle}, title = {Corticothalamic projections control synchronization in locally coupled bistable thalamic oscillators}, journal = {Physical Review Letters}, pages = {068102}, volume = {99}, year = {2007}, abstract = {Thalamic circuits are able to generate state-dependent oscillations of different frequencies and degrees of synchronization. However, little is known about how synchronous oscillations, such as spindle oscillations in the thalamus, are organized in the intact brain. Experimental findings suggest that the simultaneous occurrence of spindle oscillations over widespread territories of the thalamus is due to the corticothalamic projections, as the synchrony is lost in the decorticated thalamus. In this Letter we study the influence of corticothalamic projections on the synchrony in a thalamic network, and uncover the underlying control mechanism, leading to a control method ...
Liu, J.; Wannier, T.; Rouiller, E.M.; Jeanmonod, D.; Morel, A., 2000: Organization of thalamic projections to frontal motor areas m1, PMd, SMA and pre-SMA in relation to pallidothalamic pathways a multiple tracer study in monkey
Microsaccades during fixation have been suggested to counteract visual fading. Recent experi- ments have also observed microsaccade-related neural responses from cellular record, scalp elec- troencephalogram (EEG) and functional magnetic resonance imaging (fMRI). The underlying mechanism, however, is not yet understood and highly debated. It has been proposed that the neural activity of primary visual cortex (V1) is a crucial component for counteracting visual adaptation. In this paper, we use computational modeling to investigate how short-term depres- sion (STD) in thalamocortical synapses might affect the neural responses of V1 in the presence of microsaccades. Our model not only gives a possible synaptic explanation for microsaccades in counteracting visual fading, but also reproduces several features in experimental findings. These modeling results suggest that STD in thalamocortical synapses plays an important role in microsaccade-related neural responses and the model may be useful for further
The thalamus is a very vital part of the brain. The major role of the thalamus is to be a gateway for information to travel to the cortex. For example, visual information from the retina is not sent directly to the visual cortex. It first has to travel through the thalamus. Also, in order to relay information on sound and touch it must first pass through the thalamus. It is the major relay stations for most sensory impulses that reach the primary sensory areas of the cerebral cortex from the spinal cord and brain stem. The thalamus also contributes to motor functions by transmitting information from the cerebellum and basal ganglia to the primary motor area of the cerebral cortex. It also relays nerve impulses between different areas of the cerebrum and plays a role in the maintenance of consciousness. There are two major parts to the thalamus. ...
A cascade of simple mechanisms influences thalamic innervation of the neocortex. The cortex exerts a remote growth-promoting influence on thalamic axons when they start to grow out, becomes growth-permissive when the axons begin to invade, and later expresses a stop signal, causing termination in layer 4. However, any part of the thalamus will innervate any region of developing cortex in culture, and the precise topographic distribution of thalamic fibres in vivo is unlikely to depend exclusively on regional chemoaffinity. The handshake hypothesis proposes that axons from the thalamus and from early-born cortical preplate cells meet and intermingle in the basal telencephalon, whereafter thalamic axons grow over the scaffold of preplate axons, and become captured for a waiting period in the subplate layer below the corresponding part of the cortex. The bizarre pattern of development of thalamic innervation in the mutant reeler mouse provides strong evidence that thalamic axons are guided by
In the present study, we showed that a mild cooling of the cortex reversibly eliminated silent states and led to persistent thalamocortical activity in lightly anesthetized mice. Spontaneous IPSPs within the VPM neurons disappeared during cooling-induced cortical activation. Similarly, mild cortical cooling prevented the generation of cortical silent states in non-anesthetized head-restrained mice. Under the lesser physiological condition of deep anesthesia, a moderate cooling of the cortex reduced slow-wave synchrony but did not prevent the generation of slow waves. It also evoked fast cortical LFP spikes with frequencies ranging from 6 to 9 Hz, which correlated to spindle-like IPSPs within the VPM neurons and depolarizing events within the PO neurons. Our data point to a strong cortical control of thalamic activities.. The essential finding of this study is that a moderate cortical cooling in lightly anesthetized or naturally sleeping mice transforms the slow-wave pattern of neuronal activity ...
Glutamatergic principal neurons, GABAergic interneurons and thalamocortical axons (TCAs) are essential elements of the cerebrocortical network. Principal neurons originate locally from radial glia and intermediate progenitors (IPCs), whereas interneurons and TCAs are of extrinsic origin. Little is known how the assembly of these elements is coordinated. C-X-C motif chemokine 12 (CXCL12), which is known to guide axons outside the neural tube and interneurons in the cortex, is expressed in the meninges and IPCs. Using mouse genetics, we dissected the influence of IPC-derived CXCL12 on TCAs and interneurons by showing that Cxcl12 ablation in IPCs, leaving meningeal Cxcl12 intact, attenuates intracortical TCA growth and disrupts tangential interneuron migration in the subventricular zone. In accordance with strong CXCR4 expression in the forming thalamus and TCAs, we identified a CXCR4-dependent growth-promoting effect of CXCL12 on TCAs in thalamus explants. Together, our findings indicate a cell-autonomous
The results of our study demonstrated that slow intrathalamic oscillatory activity was significantly enhanced in brain slices from PLCβ4−/− mice (Fig. 5). Within the intrathalamic circuit consisting of reciprocal connections between the TC and TRN nuclei, PLCβ4 is almost exclusively expressed in TC neurons with tight linkage with the mGluR1, whereas no expression is found in the TRN [24, 25]. Therefore, these results suggested that the enhanced intrathalamic oscillations in the PLCβ4−/− slices were caused by the deletion of PLCβ4 in the TC neurons. The intrathalamic oscillations that were induced by a single electrical stimulus to the in vitro IC have often been examined in order to better understand the mechanisms underlying the sleep rhythms or spike wave discharges that are generated in the thalamocortical circuit [29-31]. Thus, the findings of enhanced intrathalamic oscillations in the PLCβ4−/− thalamic slices were in good agreement with the findings of significant increases ...
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Mammalian thalamocortical relay (TCR) neurons switch their firing activity between a tonic spiking and a bursting regime. In a combined experimental and computational study, we investigated the features in the input signal that single spikes and bursts in the output spike train represent and how this code is influenced by the membrane voltage state of the neuron. Identical frozen Gaussian noise current traces were injected into TCR neurons in rat brain slices to adjust, fine-tune and validate a three-compartment TCR model cell (Destexhe et al. 1998, accession number 279). Three currents were added: an h-current (Destexhe et al. 1993,1996, accession number 3343), a high-threshold calcium current and a calcium- activated potassium current (Huguenard & McCormick 1994, accession number 3808). The information content carried by the various types of events in the signal as well as by the whole signal was calculated. Bursts phase-lock to and transfer information at lower frequencies than single spikes. ...
Mammalian thalamocortical relay (TCR) neurons switch their firing activity between a tonic spiking and a bursting regime. In a combined experimental and computational study, we investigated the features in the input signal that single spikes and bursts in the output spike train represent and how this code is influenced by the membrane voltage state of the neuron. Identical frozen Gaussian noise current traces were injected into TCR neurons in rat brain slices to adjust, fine-tune and validate a three-compartment TCR model cell (Destexhe et al. 1998, accession number 279). Three currents were added: an h-current (Destexhe et al. 1993,1996, accession number 3343), a high-threshold calcium current and a calcium- activated potassium current (Huguenard & McCormick 1994, accession number 3808). The information content carried by the various types of events in the signal as well as by the whole signal was calculated. Bursts phase-lock to and transfer information at lower frequencies than single spikes. ...
Hearing loss is a major cause of morbidity and social disengagement in the aging population. Unfortunately, hearing aids, which compensate for the peripheral de...
The laterodorsal nucleus (LDN) of the thalamus provides a prominent afferent projection to the postsubiculum (dorsal presubiculum). To characterize synaptic transmission in this pathway, we placed stimulating electrodes in the LDN and recorded fEPSPs elicited in the postsubiculum of urethane-anesthetized rats. LDN stimulation elicited a source-sink dipole between the deep and superficial layers of the postsubiculum, respectively, consistent with anatomical evidence for the termination of thalamic afferents in the superficial layers of the structure, and the existence of deep layer neurons with apical dendrites extending into these layers. Postsubicular fEPSPs were typically 0.5-1.0 mV in amplitude, with a peak latency of approximately 6 ms. Consistent with anatomical observations, the short onset latency of fEPSPs elicited by LDN stimulation, and their ability to follow a 60-Hz train of stimulation, indicate that the projection is monosynaptic. Paired-pulse stimulation revealed pronounced ...
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Every day, we constantly absorb information through our sensory organs, which the brain then needs to process correctly. The information initially reaches the thalamus and then travels to the cerebral cortex. The neurons in the so-called higher-order thalamus form the connecting lines between both brain areas. Prior to this, their role in sensory processing was unknown. Scientists at the Technical University of Munich have now shown that they enhance and temporarily store sensory information.
1.The upper part of thalamus may be disc shaped, cup-shaped or flask-shaped. 2.Calyx, corolla and androecium arise from around the ovary and not beneath it. 3.Ovary is half-superior/half-inferior. 4.The ovary is placed at the bottom of cup or flask-shaped thalamus. Ovary wall is not fused with the thalamus. 5.Calyx, corolla and androecium often develop from …. Read more ...
BERKELEY -- Neuroscientists thought they understood the basic process.. During very early development, while were still in the womb, the different areas of the brain are wired like a nation-wide phone network.. Only later do our eyes, ears and other senses turn on and begin firing signals through the network - analogous to person-to-person phone calls - that prune and fine-tune the connections so that our senses are mapped in fine detail on the cerebral cortex.. A study reported in the July 24 issue of Science points out an important exception to this scenario. Susan Catalano and Carla Shatz of the University of California, Berkeley, found that even in very early development, electrical firing is essential if the nerve cell axons growing out of the thalamus are to make the right connection in the neocortex of the brain.. The thalamus is a vital way station within the brain. All of the information coming from the sensory organs, such as the eyes, ears and skin surface, passes through the ...
A major challenge in experimental data analysis is the validation of analytical methods in a fully controlled scenario where the justification of the interpretation can be made directly and not just b
Online Doctor Chat - Bilateral hyperintensities in thalami basalgangalia, Ask a Doctor about Optic nerve, Online doctor patient chat conversation by Dr. Chakravarthy Mazumdar
This article does not come from the CCSVI world, but from mainstream neurology research. Of course, association does not imply causality, but just association is very interesting. Hypoperfusion of the thalamus is associated with disability in relapsing remitting multiple sclerosis. ...
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Patients under the influence of Cortexin improves cerebral circulation, increases the volume velocity of blood flow, decreases the asymmetry of cerebral hemodynamics [8].. Thus, in elderly patients, the course treatment with Cortexin causes activation of motor activity, memory, improvement of the emotional and motivational sphere, which is probably due to the effect of the drug on the cortical-subcortical structures of the brain. Improvement of cognitive functions is associated with an increase in the functional activity of frontostriary and thalamocortical connections [15].Mechanisms of activation of neurodynamic processes are due to the regulating effect of Cortexin on the ratio of inhibition and excitation. The presented data give grounds to include Cortexin in complex therapy of patients with different stages of dyscirculatory encephalopathy. Given the neurotrophic effect of the drug, it is necessary to conduct repeated courses of therapy. Activating effect of Cortexin and on the ...
In our laboratory, we are interested in how early events in brain development such as patterning of the neural tube and cell type specification eventually lead to the formation of specific neuronal connectivity and development of animal behavior. We are particularly interested in the thalamus and brain regions that are connected to the thalamus, including the neocortex. We extensively use mouse genetics and in vivo gene delivery to study: 1) how multiple thalamic nuclei are formed and 2) how the thalamus development influences the formation of mature areas in the neocortex.. ...
Andrew Bagshaw (School of Psychology) and Theo Arvanitis (School of Electronic, Electrical & Computer Engineering) have been awarded a £716,000 EPSRC grant for a new project: The Human Brain as a Complex System: Investigating the Relationship between Structural and Functional Networks in the Thalamocortical System.
Expression of a drug-inducible Cre recombinase downstream of E-SARE enabled imaging of neuronal populations that respond to monocular visual stimulation and tracking of their long-distance thalamocortical projections in living mice ...
Lewis, Laura D; Voigts, Jakob; Flores, Francisco J; Schmitt, L Ian; Wilson, Matthew A; Halassa, Michael M; Brown, Emery N (eLife, 2015) Link to Published Version ...
Thalamocortical axons (TCAs) originate in dorsal thalamus, extend ventrally along the lateral thalamic surface, and as they approach hypothalamus make a lateral turn into ventral telencephalon. In vitro studies show that hypothalamus releases a chemorepellent for TCAs, and analyses of knockout mice indicate that Slit chemorepellents and their receptor Robo2 influence TCA pathfinding. We show that Slit chemorepellents are the hypothalamic chemorepellent and act through Robos to steer TCAs into ventral telencephalon. During TCA pathfinding, Slit1 and Slit2 are expressed in hypothalamus and ventral thalamus and Robo1 and Robo2 are expressed in dorsal thalamus. In collagen gel cocultures of dorsal thalamus and Slit2-expressing cells, axon number and length are decreased on the explant side facing Slit2-expressing cells, overall axon outgrowth is diminished, and axons turn away from the Slit2-expressing cells. Thus, Slit2 is an inhibitor and chemorepellent for dorsal thalamic axons. Collagen gel cocultures
TY - JOUR. T1 - Two epochs in the development of γ-aminobutyric acidergic neurons in the ferret thalamus. AU - Hayes, Shawn G.. AU - Murray, Karl D. AU - Jones, Edward G.. PY - 2003/8/11. Y1 - 2003/8/11. N2 - These studies chart the development of γ-aminobutyric acid (GABA)-ergic neurons in the three divisions of the thalamus (ventral thalamus, dorsal thalamus, and epithalamus). GABAergic neurons were identified by in situ hybridization to localize mRNA for 67-kDa glutamic acid decarboxylase (GAD67) and related to the morphological maturation of the thalamus in fetal and postnatal brains and to expression of transcription factors Gbx-2 and Tbr-1. Origins of GABAergic neurons were sought in in vitro slice preparations incubated in bromodeoxyuridine or injected with a carbocyanine dye. GABA neurons of ventral thalamus (reticular nucleus, ventral lateral geniculate nucleus, zona incerta, and nucleus of the fields of Forel) and of epithalamus appear at least 14 days before those intrinsic to ...
Human and experimental studies indicate that molecular genetic changes in GABAA receptors may underlie the expression of spike-and-waves discharges (SWDs) occurring during absence seizures. However, the full spectrum of the genetic defects underlying these seizures has only been partially elucidated, the expression and functional profiles of putative abnormal protein(s) within the thalamocortical network are undefined, and the pathophysiological mechanism(s) by which these proteins would lead to absence paroxysms are poorly understood. Here we investigated GABAA inhibitory postsynaptic currents (IPSCs) in key thalamocortical areas, i.e., the somatosensory cortex, ventrobasal thalamus (VB) and nucleus reticularis thalami (NRT), in preseizure genetic absence epilepsy rats from Strasbourg (GAERS), a well-established genetic model of typical absence seizures that shows no additional neurological abnormalities, and compared their properties to age-matched non-epileptic controls (NECs). Miniature ...
Internal monitoring of oculomotor commands may help to anticipate and keep track of changes in perceptual input imposed by our eye movements. Neurophysiological studies in non-human primates identified corollary discharge signals of oculomotor commands that are conveyed via thalamus to frontal cortices. We tested whether disruption of these monitoring pathways on the thalamic level impairs the perceptual matching of visual input before and after an eye movement in human subjects. Fourteen patients with focal thalamic stroke and twenty healthy control subjects performed a task requiring a perceptual judgment across eye movements. Subjects reported the apparent displacement of a target cue that jumped unpredictably in sync with a saccadic eye movement. In a critical condition of this task, six patients exhibited clearly asymmetric perceptual performance for rightward versus leftward saccade direction. Furthermore, perceptual judgments in seven patients systematically depended on oculomotor targeting
The visual thalamus of rodents has served as an important model for exploring the cellular and molecular mechanisms that underlie neural circuit formation. The overwhelming majority of these studies have focused on inputs to and projections from the dorsal lateral geniculate nucleus (dLGN). Relay neurons within dLGN receive strong glutamatergic inputs from retinal ganglion cells (RGCs) and serve as the principle conduit of visual signaling to the cortex. However, relay neurons do not act as passive relays of visual information. The gain of retinogeniculate signal transmission is modulated by nonretinal inputs to dLGN. These nonretinal inputs arise from visual cortex, pretectum, brainstem, thalamic reticular nuclei, and local dLGN interneurons, and they far outnumber the more powerful retinal inputs [1, 2]. In fact, nonretinal inputs account for as much as 95% of the nerve terminals in dLGN [1, 3-6].. Differences in the functional properties of inputs to dLGN translate into distinct neurochemical ...
This section is 5 mm. above the previous level. The medial lemnisci have now terminated within the ventral posterior lateral nuclei of the thalamus (5). On the left fibers from this nucleus are visible as they pass toward the internal capsule to form the parietal stalk or sensory radiation of the thalamus (5, upper pointer). The capsule of the red nucleus (6) consists largely of fibers which pass from the opposite dentate nucleus of the cerebellum by way of the brachium conjunctivum to the ventral lateral nucleus of the thalamus ...
TY - JOUR. T1 - Graded and areal expression patterns of regulatory genes and cadherins in embryonic neocortex independent of thalamocortical input. AU - Nakagawa, Yasushi. AU - Johnson, Jane E.. AU - OLeary, Dennis D M. PY - 1999/12/15. Y1 - 1999/12/15. N2 - The differentiation of areas of the mammalian neocortex has been hypothesized to be controlled by intrinsic genetic programs and extrinsic influences such as those mediated by thalamocortical afferents (TCAs). To address the interplay between these intrinsic and extrinsic mechanisms in the process of arealization, we have analyzed the requirement of TCAs in establishing or maintaining graded or areal patterns of gene expression in the developing mouse neocortex. We describe the differential expression of Lhx2, SCIP, and Emx1, representatives of three different classes of transcription factors, and the type I1 classical cadherins Cad6 Cad8, and Cad11, which are expressed in graded or areal patterns, as well as layer- specific patterns, in ...
Our results show that patients diagnosed with the atypical parkinsonian disorders CBS and PSP exhibit not only global differences in thalamic volume but also localized alterations in shape and ADC within thalamic motor nuclear regions (ventral anterior, VLa, and VLp) compared with patients with PD and controls. These changes are spatially concordant, supporting the concept of disproportionate motor thalamus involvement in these 2 disorders. Furthermore, similar changes were not found in patients with PD; this finding suggests that the differences may be specific to tau neurodegeneration. These results provide imaging evidence for alterations in thalamic substructure in atypical parkinsonism and corroborate existing histopathologic data showing motor thalamus degeneration in postmortem-confirmed cases of these disorders.1⇓-3,6. In contrast to most prior studies that included the thalamus, we used fully automated analysis of images from a single 3T MR imaging scanner instead of manual ...
An electron beam projection system having a projection lens arranged so that upon pre-deflection of the electron beam the electron optical axis of the lens shifts to be coincident with the deflected beam. The projection system includes means for producing an electron beam, means for deflecting the beam, a magnetic projection lens having rotational symmetry for focusing the deflected beam and a pair of magnetic compensation yokes positioned within the bore of the projection lens means. The pair of correction yokes has coil dimensions such that, in combination, they produce a magnetic compensation field proportional to the first derivative of the axial magnetic field strength distribution curve of the projection lens. Upon application of current to the pair of compensation yokes the electron optical axis of the projection lens shifts to the position of the deflected beam so that the electron beam remains coincident with the shifted electron optical axis and lands perpendicular to a target.
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Background The dorsal lateral geniculate nucleus (dLGN) of the mouse has been an important experimental model for understanding thalamic circuit development. The developmental remodeling of retinal projections has been the primary focus, however much less is known about the maturation of their synaptic targets, the relay cells of the dLGN. Here we examined the growth and maturation of relay cells during the first few weeks of life and addressed whether early retinal innervation affects their development. To accomplish this we utilized themath5 null (math5−/−) mouse, a mutant lacking retinal ganglion cells and central projections. Results The absence of retinogeniculate axon innervation led to an overall shrinkage of dLGN and disrupted the pattern of dendritic growth among developing relay cells. 3-D reconstructions of biocytin filled neurons frommath5−/− mice showed that in the absence of retinal input relay cells undergo a period of exuberant dendritic growth and branching, followed by branch
The medial geniculate body (MGB) of the thalamus is a key component of the auditory system. It is involved in relaying and transforming auditory information to the cortex and in top-down modulation of processing in the midbrain, brainstem, and ear. Functional imaging investigations of this region in humans, however, have been limited by the difficulty of distinguishing MGB from other thalamic nuclei. Here, we introduce two methods for reliably delineating MGB anatomically in individuals based on conventional and diffusion MRI data. The first uses high-resolution proton density weighted scanning optimized for subcortical grey-white contrast. The second uses diffusion-weighted imaging and probabilistic tractography to automatically segment the medial and lateral geniculate nuclei from surrounding structures based on their distinctive patterns of connectivity to the rest of the brain. Both methods produce highly replicable results that are consistent with published atlases. Importantly, both methods rely
Tinnitus is the perception of a sound in the absence of a corresponding external sound source. Pathophysiologically it has been attributed to bottom-up deafferentation and/or top-down noise-cancelling deficit. Both mechanisms are proposed to alter auditory -thalamocortical signal transmission, resulting in thalamocortical dysrhythmia (TCD). In deafferentation, TCD is characterized by a slowing down of resting state alpha to theta activity associated with an increase in surrounding gamma activity, resulting in persisting cross-frequency coupling between theta and gamma activity. Theta burst-firing increases network synchrony and recruitment, a mechanism, which might enable long-range synchrony, which in turn could represent a means for finding the missing thalamocortical information and for gaining access to consciousness. Theta oscillations could function as a carrier wave to integrate the tinnitus-related focal auditory gamma activity in a consciousness enabling network, as envisioned by the ...
Adaptation differentially influences the thalamus and cortex in a manner that fundamentally changes the nature of information conveyed about whisker motion," explained Stanley. "Our results provide a direct link between the long-observed phenomenon of enhanced sensory performance with adaptation and the underlying neurophysiological representation in the primary sensory cortex.". The thalamus serves as a relay station between the outside world and the cortex. Areas of the cortex receive and process information related to vision, audition and touch from the thalamus.. The study also revealed that information the cortex receives from the thalamus is transformed as it travels through the pathway due to a change in the level of simultaneous firing of neurons in the thalamus. The researchers found that the effect of adaptation on the synchrony of neurons in the thalamus was the key element in the shift between sensory input detection and discrimination.. "There is a switching of the circuit to a ...
ConclusionThese results highlight the relevance of volume loss in the thalamus as a key metric for predicting disability worsening as assessed by EDSS (in RRMS). Moreover, the volume loss in specific nuclei such as the ventral lateral nucleus seems to play a role in disability worsening....
FIGURE 2 The basal ganglia motor loop. Major connections linking motor cortex, basal ganglia (blue box), and thalamus are shown in this simplified scheme. Cortical areas representing all three levels of the motor hierarchy project to the neostriatum (caudate and putamen). Output from the basal ganglia is via the globus pallidus and substantia nigra to three nuclei of the thalamus. The thalamus completes the loop pathway with projections back to the motor cortex, particularly the supplemental motor area.. FIGURE 3 Connections of the direct and indirect pathways in the basal ganglia motor loop. The overall role of the basal ganglia (blue box) is to maintain inhibitory control over the thalamus. Inhibitory influence (-) is shown with blue arrows and excitatory influence ( + ) is shown with black arrows. Pathways through the basal ganglia are tonically active and coordinate converging excitatory input from the cortex through two separate routes, both of which feed back to the cortex through the ...
Sigma-Aldrich offers abstracts and full-text articles by [Clémentine Bosch-Bouju, Roseanna A Smither, Brian I Hyland, Louise C Parr-Brownlie].
The thalamus has now been almost completely removed, the anterior and medial portion being all that remains. The subthalamic nucleus is left in place. Fibers of the ansa lenticularis (5) lie above this nucleus and pass laterally toward the ventral lateral nucleus (now removed) and ventral anterior nucleus (removed). The mass of fibers which forms the posterior stalk of the thalamus is visible in the lateral and posterior wall of the thalamic dissection. The fasciculus retroflexus is exposed farther ventrally toward the interpeduncular fossa ...