TY - JOUR. T1 - Ultrastructural study of the primary olfactory pathway in Macaca fascicularis. AU - Herrera, Loren P.. AU - Casas, Carlos E.. AU - Bates, Margaret L.. AU - Guest, James D. PY - 2005/8/8. Y1 - 2005/8/8. N2 - Olfactory ensheathing glial cells (OEGs) interact with a wide repertoire of cell types and support extension of olfactory axons (OAs) within the olfactory pathway. OEGs are thought to exclude OAs from contact with all other cells between the olfactory epithelium and the glomerulus of the olfactory bulb. These properties have lead to testing to determine whether OEGs support axonal growth following transplantation. The cellular interactions of transplanted OEGs will probably resemble those that occur within the normal pathway where interactions between OEGs and fibroblasts are prominent. No previous primate studies have focused on these interactions, knowledge of which is important if clinical application is envisioned. We describe the detailed intercellular interactions of OAs ...
A Specialized Odor Memory Buffer in Primary Olfactory Cortex. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
The mammalian olfactory cortex is a complex structure located along the rostro-caudal extension of the ventrolateral prosencephalon, which is divided into several anatomically and functionally distinct areas: the anterior olfactory nucleus, piriform cortex, olfactory tubercle, amygdaloid olfactory nuclei, and the more caudal entorhinal cortex. Multiple forebrain progenitor domains contribute to the cellular diversity of the olfactory cortex, which is invaded simultaneously by cells originating in distinct germinal areas in the dorsal and ventral forebrain. Using a combination of dye labeling techniques, we identified two novel areas that contribute cells to the developing olfactory cortices, the septum and the ventral pallium, from which cells migrate along a radial and then a tangential path. We characterized these cell populations by comparing their expression of calretinin, calbindin, reelin and Tbr1 with that of other olfactory cell populations.
Olfactory Pathways, part of the limbic system, are a set of nerve fibers conducting impulses from olfactory receptors to the cerebral cortex
The antennal lobe is the deutocerebral neuropil of insects which receives the input from the olfactory sensory neurons on the antenna. Functionally, it shares some similarities with the olfactory bulb in vertebrates.. In insects, the olfactory pathway starts at the antennae (though in some insects like Drosophila there are olfactory sensory neurons in other parts of the body) from where the sensory neurons carry the information about the odorant molecules impinging on the antenna to the antennal lobe.[1] The antennal lobe is composed of densely packed neuropils, termed glomeruli, where the sensory neurons synapse with the two other kinds of neurons, the projection neurons and the local neurons.[1] There are 43 glomeruli in the Drosophila antennal lobe; in Aedes aegypti there are 32;[1] locusts and social wasps may have over 1000.[1] The projection neurons project to higher brain centers such as the mushroom body and the lateral horn.[2] [3] [4] The local neurons, which are primarily inhibitory, ...
Li backed up these findings with scans of the volunteers brains. She used a technique called functional magnetic resonance imaging (fMRI) to show that their learning experiences were mirrored by changes in their posterior piriform cortex (PPC), a part of the brain involved in learning new smells. At the start of the study, sniffing both forms of 2-butanol triggered similar patterns of activity in the PPC. After the shock, these patterns became more distinct, even though the overall level of activity in the region stayed the same. In contrast, the patterns for the rose oxide molecules remained strongly coupled throughout the study. Adaptive sniffing Weve known for decades that a shocking stimulus can condition an animal towards certain types of behaviour, but this study clearly shows that it can also make an animal more sensitive to the stimulus in question. Clearly, animals benefit from being able to discern the smell of danger and ignore unimportant odours. As Li herself put it, the whiff of ...
Rodents can successfully learn multiple novel stimulus-response associations after only a few repetitions when the contingencies predict reward. The circuits modified during such reinforcement learning to support decision-making are not known, but the olfactory tubercle (OT) and posterior piriform cortex (pPC) are candidates for decoding reward category from olfactory sensory input and relaying this information to cognitive and motor areas. Through single-cell recordings in behaving male and female C57BL/6 mice, we show here that an explicit representation for reward category emerges in the OT within minutes of learning a novel odor-reward association, whereas the pPC lacks an explicit representation even after weeks of overtraining. The explicit reward category representation in OT is visible in the first sniff (50-100 ms) of an odor on each trial, and precedes the motor action. Together, these results suggest that the coding of stimulus information required for reward prediction does not occur ...
An essential feature of the organization and function of the vertebrate and insect olfactory systems is the generation of a variety of olfactory receptor neurons (ORNs) that have different specificities in regard to both odorant receptor expression and axonal targeting. Yet the underlying mechanisms …
The major finding of this study is that antennal lobe projection neurons and mushroom body Kenyon cells express different sets of ionic currents.. Kenyon cells express at least three different voltage-gated outward K+ currents. The transient component comprises a rapidly inactivating (A-type) current and a slowly inactivating current, whose kinetic parameters have been described in great detail (Pelz et al., 1999). The amplitude of the sustained (delayed rectifier) current is relatively small compared to the transient K+ currents, as described in various insect or crustacean neurons (e.g. Byerly and Leung, 1988; Saito and Wu, 1991; Hayashi and Levine, 1992; Delgado et al., 1998; Kloppenburg and Hörner, 1998; Benkenstein et al., 1999; Kloppenburg et al., 1999b; Schmidt et al., 2000 (for a review, see Wicher et al., 2001) and in antennal motoneurons within the honeybee deutocerebrum (Kloppenburg et al., 1999a). By contrast, projection neurons do not express such prominent transient K+ currents. ...
The Drosophila olfactory system exhibits very precise and stereotyped wiring that is specified predominantly by genetic programming. Dendrites of olfactory projection neurons (PNs) pattern the developing antennal lobe before olfactory receptor neuron axon arrival, indicating an intrinsic wiring mechanism for PN dendrites. These wiring decisions are likely determined through a transcriptional program. This study found that loss of Brahma associated protein 55 kD (Bap55) results in a highly specific PN mistargeting phenotype. In Bap55 mutants, PNs that normally target to the DL1 glomerulus mistarget to the DA4l glomerulus with 100% penetrance. Loss of Bap55 also causes derepression of a GAL4 whose expression is normally restricted to a small subset of PNs. Bap55 is a member of both the Brahma (BRM) and the Tat interactive protein 60 kD (TIP60) ATP-dependent chromatin remodeling complexes. The Bap55 mutant phenotype is partially recapitulated by Domino and Enhancer of Polycomb mutants, members of ...
In approximately 60% of adult preparations, a few terminal branches cross the midline to innervate the antennal lobe ipsilateral to the soma (arrow in Figure 1c, h); these collaterals are not observed at the larval stage (Figure 1b, i). The larval olfactory system lacks an antennal commissure (Subhashini Srinivasan, unpublished observations), which in the adult carries contralateral branches of a majority of ORNs and some PNs that connect both lobes [4]. The terminals of the CSDn in the lobe contralateral to the soma are blebby in appearance, strongly serotonin positive (Figure 2b) and resemble structures of the B. mori CSD neuron that were shown by electron microscopy to be presynaptic to some of the neural elements within the lobe [20]. In order to confirm that these endings are presynaptic, we expressed a GFP-tagged synaptotagmin (Syt-GFP) in the CSDn and found the protein highly enriched in the terminal endings (Additional file 2c, f) and not in the ipsilateral arbors (Additional file 2a). ...
Van de Bittner GC, Riley MM, Cao L, Ehses J, Herrick SP, Ricq EL, Wey HY, ONeill MJ, Ahmed Z, Murray TK, Smith JE, Wang C, Schroeder FA, Albers MW, Hooker JM. Nasal neuron PET imaging quantifies neuron generation and degeneration. J Clin Invest. 2017 Feb 01; 127(2):681-694 ...
Such observations reinforced the prospect that the biological events underlying chemi- cally induced toxicity are complex and that the encapsulate concentrations of covalently bound adducts in macromolecules is not the solitary determinant of toxicity per se. A swatting following kainate-induced seizures showed that the cyclin D1 mRNA was induced in the vulnerable CA3 part, and to a lesser extent, in non-vulnerable regions, while that the expression of CDK4 and cyclin D1 was upregu- lated in neurons of the rat piriform cortex and amygdala 1В-3 days after KA administra- tion in vivo. Who Is Agonistic by Fibromyalgia toradol 10 mg on-line pain medication for dogs aleve. The thin film of a childish stripling may let someone have the visualization of cursory venous circulation across the abdomen. Perhaps a couple of centuries later, the grey Hebrews displayed presumptuousness with this pursuit: in the Out-moded Testament, the perpetually tormented Responsibility cries prohibited The arrows of the ...
Such observations reinforced the prospect that the biological events underlying chemi- cally induced toxicity are complex and that the encapsulate concentrations of covalently bound adducts in macromolecules is not the solitary determinant of toxicity per se. A swatting following kainate-induced seizures showed that the cyclin D1 mRNA was induced in the vulnerable CA3 part, and to a lesser extent, in non-vulnerable regions, while that the expression of CDK4 and cyclin D1 was upregu- lated in neurons of the rat piriform cortex and amygdala 1В-3 days after KA administra- tion in vivo. Who Is Agonistic by Fibromyalgia toradol 10 mg on-line pain medication for dogs aleve. The thin film of a childish stripling may let someone have the visualization of cursory venous circulation across the abdomen. Perhaps a couple of centuries later, the grey Hebrews displayed presumptuousness with this pursuit: in the Out-moded Testament, the perpetually tormented Responsibility cries prohibited The arrows of the ...
If the lateral olfactory tract (LOT) of the golden hamster is transected in the first week of postnatal life, axons will grow back through the cut and reinnervate the terminal regions. Functional recovery occurs only when the terminal regions are reinnervated. The experiments reported here tested the hypothesis that reinnervation is due to neogenesis: the continued growth of newly formed axons which were not severed by the lesion. In the first experiment the birth dates of the mitral and tufted cells were determined in the hamster. It was found that mitral cells are formed on gestational days 11 and 12 (E11 and E12) and tufted cells on E11 to E14. Experiment 2 involved the combination of [3H]thymidine labeling, for the time of cell formation, with the retrograde transport of horseradish peroxidase (HRP), at a time when the LOT projections are not yet complete. The axons of early formed cells were found to reach the olfactory cortex before those of later formed cells. Experiment 3 examined the ...
Author Summary Many lines of evidence suggest that few spikes carry the relevant stimulus information at later stages of sensory processing. Yet mechanisms for the emergence of a robust and temporally sparse sensory representation remain elusive. Here, we introduce an idea in which a temporal sparse and reliable stimulus representation develops naturally in spiking networks. It combines principles of signal propagation with the commonly observed mechanism of neuronal firing rate adaptation. Using a stringent numerical and mathematical approach, we show how a dense rate code at the periphery translates into a temporal sparse representation in the cortical network. At the same time, it dynamically suppresses trial-by-trial variability, matching experimental observations in sensory cortices. Computational modelling of the insects olfactory pathway suggests that the same principle underlies the prominent example of temporal sparse coding in the mushroom body. Our results reveal a computational principle
The olfactory bulb (OB) is the first processing station in the olfactory pathway. Despite smell impairment, which is considered an early event in Alzheimers disease (AD), little is known about the initial molecular ...
1. A large-scale computer model of the piriform cortex was constructed on the basis of the known anatomic and physiological organization of this region. 2. The oscillatory field potential and electroencephalographic (EEG) activity generated by the model was compared with actual physiological results. The model was able to produce patterns of activity similar to those recorded physiologically in response to both weak and strong electrical shocks to the afferent input. The model also generated activity patterns similar to EEGs recorded in behaving animals. 3 ...
Date: 07/18/2008 05:53 PMBy PEGGY HARRISAssociated Press WriterLITTLE ROCK, Ark. (AP) _ Because of his own injuries, Ben Vereen seems like a natural to hig
Hyperosmia is an increased olfactory acuity (heightened sense of smell), usually caused by a lower threshold for odor. This perceptual disorder arises when there is an abnormally increased signal at any point between the olfactory receptors and the olfactory cortex. The causes of hyperosmia may be genetic, environmental or the result of benzodiazepine withdrawal syndrome. When odorants enter the nasal cavity, they bind to odorant receptors at the base of the olfactory epithelium. These receptors are bipolar neurons that connect to the glomerular layer of the olfactory bulb, traveling through the cribriform plate. At the glomerular layer, axons from the olfactory receptor neurons intermingle with dendrites from intrinsic olfactory bulb neurons: mitrial/tufted cells and dopaminergic periglomerular cells. From the olfactory bulb, mitral/tufted cells send axons via the lateral olfactory tract (the cranial nerve I) to the olfactory cortex, which includes the piriform cortex, entorhinal cortex, and ...
Biological olfaction outperforms chemical instrumentation in specificity, response time, detection limit, coding capacity, time stability, robustness, size, power consumption, and portability. This biological function provides outstanding performance due, to a large extent, to the unique architecture of the olfactory pathway, which combines a high degree of redundancy, an efficient combinatorial coding along with unmatched chemical information processing mechanisms. The last decade has witnessed important advances in the understanding of the computational primitives underlying the functioning of the olfactory system. EU Funded Project NEUROCHEM (Bio-ICT-FET- 216916) has developed novel computing paradigms and biologically motivated artefacts for chemical sensing taking inspiration from the biological olfactory pathway. To demonstrate this approach, a biomimetic demonstrator has been built featuring a large scale sensor array (65K elements) in conducting polymer technology mimicking the olfactory ...
Đây là một trong những cách dưỡng da tốt nhất cho làn da bị mụn và bị hao tổn do môi trường. Bạn có thể sử dụng nhiều loại mặt nạ đắp mặt từ thiên nhiên khác nhau, tuy nhiên bạn chỉ nên lựa chọn các loại mặt nạ phù hợp nhất với làn da của mình. Hãy xuy sét cẩn thận khi lựa chọn loại mặt nạ vì nó có thể gây kích ứng da khi bạn sử dụng đấy.. Thời gian tốt nhất để đắp mặt nạ là khoảng 15 phút, đừng để mặt nạ đắp mặt quá lâu vì nó có thể sẽ gây biến chất các loại vitamin và chất dưỡng da có trong mặt nạ. Bạn cũng có thể tận dụng khoảng thời gian đắp mặt nạ để thư giãn hoặc xem phim giải trí.. Một số loại mặt nạ đắp mặt tốt cho làn da như dưa leo, ngọc trai, bùn …có thể phù hợp với đại đa số làn da của bạn. Một số nhãn hiệu mặt nạ tốt ...
Đây là một trong những cách dưỡng da tốt nhất cho làn da bị mụn và bị hao tổn do môi trường. Bạn có thể sử dụng nhiều loại mặt nạ đắp mặt từ thiên nhiên khác nhau, tuy nhiên bạn chỉ nên lựa chọn các loại mặt nạ phù hợp nhất với làn da của mình. Hãy xuy sét cẩn thận khi lựa chọn loại mặt nạ vì nó có thể gây kích ứng da khi bạn sử dụng đấy.. Thời gian tốt nhất để đắp mặt nạ là khoảng 15 phút, đừng để mặt nạ đắp mặt quá lâu vì nó có thể sẽ gây biến chất các loại vitamin và chất dưỡng da có trong mặt nạ. Bạn cũng có thể tận dụng khoảng thời gian đắp mặt nạ để thư giãn hoặc xem phim giải trí.. Một số loại mặt nạ đắp mặt tốt cho làn da như dưa leo, ngọc trai, bùn …có thể phù hợp với đại đa số làn da của bạn. Một số nhãn hiệu mặt nạ tốt ...
Nidheesh Radhakrishnan Olfactory nerve: Purely Sensory Telencephalon Anterior olfactory nucleus Transmits the sense of smell. Located in olfactory foramina in the cribriform plate of ethmoid. Optic nerve Purely Sensory Diencephalon Ganglion cells of retina. Transmits […]. ...
Previous studies have demonstrated that NMDA-dependent, long-term potentiation (LTP) can be induced in both afferent and intrinsic association fiber systems in the piriform (primary olfactory) cortex. In this report we demonstrate that an associative form of LTP can be induced by coactivation of these two systems, which terminate on adjacent apical dendritic segments of pyramidal cells. Potentiating stimulus trains were delivered to either afferent or association fibers, and weak shocks, which were nonpotentiating when delivered alone, were delivered to the other pathway. Under control recording conditions where homosynaptic (single pathway) LTP is consistently evoked, coincident application of these stimuli failed to induce LTP of the weak shock response. However, after local blockade of the fast, GABAA-mediated IPSP, associative LTP was consistently produced in both directions. Induction was blocked by D-2-amino-5-phosphonovaleric acid, indicating that it is dependent on activation of NMDA receptors.
It is usually considered that the sense of smell is poorly developed in humans, in comparison, for example, to lower vertebrates, such as rats and mice. However, in view of its evolutionary significance, it seems very unlikely that the sense of smell is trivial in guiding human behavior.. The fragility of the fibers in the olfactory mucosa of the nose, their delicate passage through the cribriform plate, and the course of the olfactory tract along the orbital surface of the brain underly the vulnerability of this sensory modality to external trauma-for example, from head injury. This is compounded by the locations of structures receiving the central representations of smell, such as, for example, the primary olfactory cortex and olfactory tubercle, which lie vulnerable on the undersurface of the brain overlying the anterior perforated space.. Smell sensations may occur as part of an aura in temporal lobe epilepsy. Traditionally referred to as uncinate seizures (simple partial seizures in todays ...
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I should note that the homework question states If a sensory neuron for touch located in the elbow was somehow rewired to a persons primary olfactory cortex, then every time the persons elbow was touched, they would perceive some smell., which appears contradictory to von Melchner et als statement rewired ferrets respond as though they perceive the stimuli to be visual rather than auditory. The word perceive may be carrying different meanings here. Perhaps better language would be the animal/patient is able to receive visual/somatosensory information through its/his auditory cortex, and the information is sufficiently fine that it/he can respond with appropriate behaviour to an appropriate visual/somatosensory stimulus ...
As in mice, we performed dual optical and electrical recordings to verify the spike trains, this time using whole-cell patch-clamp electrodes to access LN neurons intracellular potentials in intact fly brain explants (Fig. 4C, left). Across 18,141 recorded spikes, the spike trains provided by Ace2N-2AA-mNeon perfectly matched those from the patch-clamp recordings (N = 4 fly brains) and had spike-timing errors of 0.19 ± 0.002 ms (SEM; N = 18,141 spikes), close to the theoretical optimum of 0.11 ± 0.03 ms (Fig. 4C, right). Subthreshold dynamics were readily apparent in the optical traces, including plateau potentials and the rising and falling voltage waveforms surrounding action potentials. Ace2N-2AA-mNeon also reported the submillisecond-scale dynamics of spike back-propagation into the dendritic tree, revealing ~0.5- to 1.0-ms delays between the initiating voltage peak at the soma and those in the dendrites (Fig. 4D and movie S2).. We next imaged olfactory projection neurons (PNs), which ...
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Lenkey, Nora and Kirizs, Tekla and Holderith, Noemi and Máté, Zoltán and Szabó, Gábor and Vizy, E. Sylvester and Hájos, Norbert and Nusser, Zoltan (2015) Tonic endocannabinoid-mediated modulation of GABA release is independent of the CB1 content of axon terminals. Nature communications, 6 (6557). pp. 1-14. ISSN 2041-1723 Szabó, Gergely G. and Papp, Orsolya I. and Máté, Zoltán and Szabó, Gábor and Hájos, Norbert (2014) Anatomically heterogeneous populations of CB cannabinoid receptor-expressing interneurons in the CA3 region of the hippocampus show homogeneous input-output characteristics. HIPPOCAMPUS, 12. pp. 1506-1523. ISSN 1050-9631 Horváth, Gergely and Gölöncsér, Flóra and Csölle, Cecília and Király, Kornél P. and Andó, Rómeó and Baranyi, Mária and Máté, Zoltán and Sperlágh, Beáta (2014) Central P2Y12 receptor blockade alleviates inflammatory and neuropathic pain and cytokine production in rodents. NEUROBIOLOGY OF DISEASE, 70. pp. 162-178. ISSN 0969-9961 Szűcs, ...
The UMC Utrecht Brain Center encompasses all research in clinical and experimental neuroscience carried out at the University Medical Center Utrecht.
Mi mắt có vai trò quan trọng trong việc bảo vệ nhãn cầu chống lại các yếu tố bên ngoài như: ánh sáng, sức nóng, bụi bặm và các dị vật khác, nhờ động...
Informacion, analiza, foto, video; në faqen e gazetës SHEKULLI do të informoheni në kohë reale për zhvillimet më të fundit nga vendi, rajoni dhe bota.
Bizoni ir lieli un masīvi pārnadži. Tēviņi ir nedaudz lielāki nekā mātītes un dažos gadījumos tēviņi ir ievērojami masīvāki un smagāki. Bizona tēviņa ķermeņa garums ir 3,6 - 3,8 m, augstums skaustā 1,67 - 1,86 m.[3] Mātītes ķermeņa garums ir 2,13 - 3,18 m, augstums skaustā 1,52 - 1,57 m.[3] Bizona masa ir 318 - 1000 kg.[4] Smagākais datētais tēviņš savvaļā ir svēris 1,27 tonnas,[4][5] bet nebrīvē bizons var izaugt vēl lielāks. Lielākais bizons nebrīvē ir sasniedzis 1,724 tonnas.[6] Aste ir vidēji gara (50 - 60 cm).[7] Bizonam ir raksturīgs plecu kupris un proporcionāli milzīga galva. Salīdzinot abas pasugas, līdzenuma bizons ir mazāks nekā meža bizons. Turklāt meža bizons salīdzinoši ir ar tumšāku matojumu un tā augstākā vieta skaustā ir nedaudz pirms priekškājām, bet līdzenuma bizonam tieši virs priekškājām. Bizonam ziemā ir garš, biezs, savēlies, tumši brūns matojums, bet vasarā kažoks kļūst gaišāks un plānāks. ...
A Rubicon t rt nelmi foly irat honlapja. A tartalma szerint tudom nyos ismeretterjeszt foly irat magazinszer en n pszer s ti a t rt nelmet. Ahogy az iskol ban nem hallhatta...
Hlad te kvalitn a cenovo dostupn prote ny, aminokyseliny i in doplnky v ivy ? Zna ka STILLMASS vznikla v roku 2008 za elom prinies na trh s v ivov mi doplnkami lacnej ie a kvalitnej ie produkty a uspokojen m t ch najn ro nej ch po iadaviek sa o
A biliopankreatikus diverzió (BPD) egy szűkítő és egy tápanyag-felszívódást korlátozó beavatkozás kombinációja. A testsúlycsökkentést célzó műtét sorá...
A (41) , B (10) , C (62) , D (5) , E (10) , F (5) , G (41) , H (10) , I (3) , K (1) , L (9) , M (18) , N (73) , O (7) , P (16) , R (6) , S (37) , T (34) , V (1) , W (16) , X (1) , Y (2) ...
Brain Regions (94): CTX (Cerebral cortex) MOB (Main olfactory bulb) AOB (Accessory olfactory bulb) AON (Anterior olfactory nucleus) TT (Taenia tecta) PIR (Piriform area) NLOT (Nucleus of the lateral olfactory tract) PAA (Piriform-amygdalar area) COA (Cortical amygdalar area) TR (Postpiriform transition area) CA (Ammons Horn) DG (Dentate gyrus) RHP (Retrohippocampal region) SUB (Subiculum) CP (Caudoputamen ) ACB (Nucleus accumbens ) FS (Fundus of striatum) OT (Olfactory tubercle ) LS (Lateral septal nucleus ) CEA (Central amygdalar nucleus ) AAA (Anterior amygdalar area) MEA (Medial amygdalar nucleus ) PALd (Pallidum_ dorsal region) PALv (Pallidum_ ventral region) BST (Bed nuclei of the stria terminalis ) PALm (Pallidum_ medial region) AM (Anteromedial nucleus) AV (Anteroventral nucleus of thalamus ) LD (Lateral dorsal nucleus of thalamus) RT (Reticular nucleus of the thalamus) LAT (Lateral group of the dorsal thalamus) LP (Lateral posterior nucleus of the thalamus) LGv (Ventral part of the ...
A unifying feature of mammalian and insect olfactory systems is that olfactory sensory neurons (OSNs) expressing the same unique odorant-receptor gene converge onto the same glomeruli in the brain [1-7]. Most odorants activate a combination of receptors and thus distinct patterns of glomeruli, forming a proposed combinatorial spatial code that could support discrimination between a large number of odorants [8-11]. OSNs also exhibit odor-evoked responses with complex temporal dynamics [11], but the contribution of this activity to behavioral odor discrimination has received little attention [12]. Here, we investigated the importance of spatial encoding in the relatively simple Drosophila antennal lobe. We show that Drosophila can learn to discriminate between two odorants with one functional class of Or83b-expressing OSNs. Furthermore, these flies encode one odorant from a mixture and cross-adapt to odorants that activate the relevant OSN class, demonstrating that they discriminate odorants by using the
Multiple factors contribute to the onset and progress of PD, that initially targets few susceptible neuron types in motor nuclei of glossopharyngeal and vagus nerves, and in the anterior olfactory nucleus [2, 3, 24]. Many animal models are available for mimicking PD landmarks, however none can reproduce in full the human pathology. The picture is even more complicated by the presence of both motor and non-motor symptoms, whose assessment in animal models may be difficult and need careful overall interpretation (for a review, see [25]). We choose the MPTP model because we were interested in olfactory dysfunctions, which are a hallmark of early PD stages. MPTP administered acutely in mice can reproduce early stages of PD [26], however, it is not sufficient for fully exploring PD, since MPTP-injected mice recover spontaneously, which precludes the study of pharmacological interventions. Moreover, various strains of mice show different sensitivity to MPTP.. PD implies a complex imbalance of the ...
In the mouse, each class of olfactory receptor neurons expressing a given odorant receptor has convergent axonal projections to two specific glomeruli in the olfactory bulb, thereby creating an odour map. However, it is unclear how this map is represented in the olfactory cortex. Here we combine rab …
Olfactory ensheathing cells (OECs) are the glial cells of the olfactory system. Their primary role is thought to be to provide support and guidance for primary olfactory axons. However, OECs are known to phagocytose bacteria and express immune markers and thus they may help to maintain a healthy environment. Interestingly, following widespread death of primary olfactory axons, there is minimal mobilisation of macrophages but yet the axonal debris is rapidly cleared. Purpose: We have therefore investigated whether OECs are the cells that are primarily responsible for removal of axonal debris. Methods: We cultured red fluorescent OECs from S100beta-DsRed mice and green fluorescent primary olfactory neurons from OMP-ZsGreen mice. Results: In explant cultures of DsRed-OECs and ZsGreen-neurons, OECs clearly contained green fluorescent axonal debris. When cellular debris from green fluorescent neurons was added to cultured OECs, the OECs extended pseudopodia and rapidly phagocytosed the axonal debris ...
Boto T, Louis T, Jindachomthong K, Jalink K, Tomchik SM (2014) Dopaminergic modulation cAMP drives nonlinear plasticity across the Drosophila mushroom body lobes. Curr Biol 24: 822-831.. Tomchik SM (2013) Dopaminergic neurons encode a distributed, asymmetric representation of temperature in Drosophila. J Neurosci 33: 2166-2176.. Tomchik SM, Davis RL (2009) Dynamics of learning-related cAMP signaling and stimulus integration in the Drosophila olfactory pathway. Neuron 64: 510-521.. Tomchik SM, Davis RL (2008) Behavioural neuroscience: Out of sight, but not out of mind. Nature 453: 1192-1194.. Tomchik SM, Davis RL (2008) Cyclic AMP imaging sheds light on PDF signaling in circadian clock neurons. Neuron 58: 161-163.. Tomchik SM, Berg S, Kim JW, Chaudhari N, Roper SD (2007) Breadth of tuning and taste coding in mammalian taste buds. J Neurosci 27: 10840-10848.. Dvoryanchikov G, Tomchik SM, Chaudhari N (2007) Biogenic amine synthesis and uptake in rodent taste buds. J Comp Neurol 505: ...
Concentration invariance - the capacity to recognize a given odorant (analyte) across a range of concentrations - is an unusually difficult problem in the olfactory modality. Nevertheless, humans and other animals are able to recognize known odors across substantial concentration ranges, and this concentration invariance is a highly desirable property for artificial systems as well. Several properties of olfactory systems have been proposed to contribute to concentration invariance, but none of these alone can plausibly achieve full concentration invariance. We here propose that the mammalian olfactory system uses at least six computational mechanisms in series to reduce the concentration-dependent variance in odor representations to a level where different concentrations of odors evoke reasonably similar representations, while preserving variance arising from differences in odor quality. We suggest that the residual variance then is treated like any other source of stimulus variance, and
Thapsigargin is an inhibitor of the Ca2+-ATPase of the endoplasmic reticulum (ER) that depletes the intracellular Ca2+ stores (Thastrup et al., 1990; Rosay et al., 2001). Thapsigargin application for 15 min (Fig. 4) clearly decreased the total number of photons (Sp: 5813±1380.8, P,0.05; Ci: 3197±494.9, P,0.05; Oct: 4732±3013.7; P,0.05), as well as the duration of the response (Sp: 28±5.4 s, P,0.0001; Ci: 22±2.0 s, P,0.001; Oct: 25±3.0 s, P,0.001). The amplitude of the first component of the response was also affected, as compared with control flies, for spearmint (P,0.05) and octanol (P,0.05; Fig. 4A,G), whereas it was not affected for citronella (Fig. 4D). These results suggest that, although thapsigargin slightly affects the amplitude of the first component (for two of the three tested odors), more importantly, it affects the second component of the response (for the three tested odors). This lead us to suggest that the first component does not necessarily involve Ca2+ release from ...
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In search of smells meaning. Gloria Chois research addresses the mechanisms by which the brain learns to recognize olfactory stimuli and to associate them with appropriate behavioral responses.. Much recent work has been devoted to the question of how the binding of odorant molecules to their receptors in the olfactory epithelium leads to the perception of odors. In other sensory modalities such as vision, touch or hearing, the primary sensory cortex shows a topographical organization in which stimulus features are systematically mapped on the cortical surface. In the olfactory area (known as piriform cortex), however, no such order has been found; while individual inputs to the cortex are tuned to specific odorants, their projections within the piriform cortex are widely dispersed. Consistent with this, olfactory stimuli typically activate sparse ensembles of piriform cells, with no obvious spatial pattern. Yet somehow the brain must learn to recognize these apparently arbitrary spatial ...
Olfactory sensory neurons express a wide variety of axon-sorting molecules to establish proper neural circuitry. This protocol...