The Experts below are selected from a list of 978 Experts worldwide ranked by ideXlab platform
Pierre-marie Lledo - One of the best experts on this subject based on the ideXlab platform.
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Development/Plasticity/Repair Functional Maturation of the First Synapse in Olfaction: Development and Adult Neurogenesis
2015Co-Authors: Matthew S. Grubb, Antoine Nissant, Kerren Murray, Pierre-marie LledoAbstract:The first synapse in olfaction undergoes considerable anatomical plasticity in both early postnatal development and adult neurogenesis, yet we know very little concerning its functionalmaturation at these times. Here, we usedwhole-Cell recordings in olfactory bulb slices to describe olfactory nerve inputs to developing postnatal neurons and tomaturing adult-born Cells labeledwith aGFP-encoding lentivirus. In both postnatal development and adult neurogenesis, the maturation of olfactory nerve synapses involved an increase in the relative contribution of AMPAoverNMDA receptors, and a decrease in the contribution of NMDA receptors containing theNR2B subunit. These postsynaptic transformations, however, were notmirrored by presynaptic changes: in all Cell groups, paired-pulse depression remained constant as olfactory nerve synapses matured. Although maturing Cells may therefore offer, transiently, a functionally distinct connec-tion for inputs from the nose, presynaptic function at the first olfactory connection remains remarkably constant in the face of consid-erable anatomical plasticity. Key words: development; adult neurogenesis; olfaction; olfactory bulb; synapse; Periglomerular Cell
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Importance of newly generated neurons in the adult olfactory bulb for odor discrimination.
Proceedings of the National Academy of Sciences of the United States of America, 2000Co-Authors: Gilles Gheusi, Harold Cremer, Heather Mclean, Geneviève Chazal, Jean-didier Vincent, Pierre-marie LledoAbstract:In adult rodents, neurons are continually generated in the subventricular zone of the forebrain, from where they migrate tangentially toward the olfactory bulb, the only known target for these neuronal precursors. Within the main olfactory bulb, they ascend radially into the granule and Periglomerular Cell layers, where they differentiate mainly into local interneurons. The functional consequences of this permanent generation and integration of new neurons into existing circuits are unknown. To address this question, we used neural Cell adhesion molecule-deficient mice that have documented deficits in the migration of olfactory-bulb neuron precursors, leading to about 40% size reduction of this structure. Our anatomical study reveals that this reduction is restricted to the granule Cell layer, a structure that contains exclusively gamma-aminobutyric acid (GABA)ergic interneurons. Furthermore, mutant mice were subjected to experiments designed to examine the behavioral consequences of such anatomical alteration. We found that the specific reduction in the newly generated interneuron population resulted in an impairment of discrimination between odors. In contrast, both the detection thresholds for odors and short-term olfactory memory were unaltered, demonstrating that a critical number of bulbar granule Cells is crucial only for odor discrimination but not for general olfactory functions.
Antonio C Roque - One of the best experts on this subject based on the ideXlab platform.
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the Periglomerular Cell of the olfactory bulb and its role in controlling mitral Cell spiking a computational model
PLOS ONE, 2013Co-Authors: Denise Costa Arruda, Rodrigo Publio, Antonio C RoqueAbstract:Interneurons in the olfactory bulb are key elements of odor processing but their roles have not yet being fully understood. Two types of inhibitory interneurons, Periglomerular and granule Cells, act at two different levels within the olfactory bulb and may have different roles in coordinating the spiking of mitral Cells, which are the principal output neurons of the olfactory bulb. In this work we introduce a reduced compartmental model of the Periglomerular Cell and use it to investigate its role on mitral Cell spiking in a model of an elementary Cell triad composed of these two Cell types plus a granule Cell. Our simulation results show that the Periglomerular Cell is more effective in inhibiting the mitral Cell than the granule Cell. Based on our results we predict that Periglomerular and granule Cells have different roles in the control of mitral Cell spiking. The Periglomerular Cell would be the only one capable of completely inhibiting the mitral Cell, and the activity decrease of the mitral Cell through this inhibitory action would occur in a stepwise fashion depending on parameters of the Periglomerular and granule Cells as well as on the relative times of arrival of external stimuli to the three Cells. The major role of the granule Cell would be to facilitate the inhibitory action of the Periglomerular Cell by enlarging the range of parameters of the Periglomerular Cell which correspond to complete inhibition of the mitral Cell. The combined action of the two interneurons would thus provide an efficient way of controling the instantaneous value of the firing rate of the mitral Cell.
Alexandra Veyrac - One of the best experts on this subject based on the ideXlab platform.
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Short term treatment with estradiol decreases the rate of newly generated Cells in the subventricular zone and main olfactory bulb of adult female mice
Neuroscience, 2010Co-Authors: O. Brock, Alexandra Veyrac, Matthieu Keller, Q. Douhard, J. BakkerAbstract:Adult neurogenesis occurs most notably in the subgranular zone (SGZ) of the hippocampal dentate gyrus and in the olfactory bulb (OB) where new neurons are generated from neural progenitors Cells produced in the subventricular zone (SVZ) of the forebrain. As it is well known that gonadal steroid hormones, primarily estradiol, modulate neurogenesis in the hippocampus of adult female rodents, we wanted to determine whether estradiol would also affect the proliferation of progenitor Cells in the SVZ and by consequence the rate of newly generated Cells in the main OB. Thus a first group of adult female C57B16/J mice was ovariectomized and received a short term treatment with estradiol (single injection of 1 or 10 mu g 17 beta-estradiol or Silastic capsule of estradiol during 2 days) before receiving a single injection with BrdU to determine whether estradiol would modulate the Cell proliferation in the SVZ. A second group of adult ovariectomized female mice was submitted to the same estradiol treatment before receiving four BrdU injections, and was sacrificed 21 days later to determine whether a modulation in Cell proliferation actually leads to a modulation in the number of newborn Cells in the main OB. We observed a decrease in Cell proliferation in the SVZ following either dose of estradiol compared to the controls. Furthermore, 21 days after their generation in the SVZ, the number of BrdU labeled Cells was also lower in the main OB, both in the granular and Periglomerular Cell layers of estradiol-treated animals. These results show that a short term treatment with estradiol actually downregulates Cell proliferation leading to a decreased number of newborn Cells in the OB. (C) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.
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Olfactory enrichment influences adult neurogenesis modulating GAD67 and plasticity-related molecules expression in newborn Cells of the olfactory bulb.
Public Library of Science (PLoS), 2009Co-Authors: Serena Bovetti, Paolo Peretto, Aldo Fasolo, Alexandra Veyrac, Silvia De MarchisAbstract:The olfactory bulb (OB) is a highly plastic region of the adult mammalian brain characterized by continuous integration of inhibitory interneurons of the granule (GC) and Periglomerular Cell (PGC) types. Adult-generated OB interneurons are selected to survive in an experience-dependent way but the mechanisms that mediate the effects of experience on OB neurogenesis are unknown. Here we focus on the new-generated PGC population which is composed by multiple subtypes. Using paradigms of olfactory enrichment and/or deprivation combined to BrdU injections and quantitative confocal immunohistochemical analyses, we studied the effects of olfactory experience on adult-generated PGCs at different survival time and compared PGC to GC modulation. We show that olfactory enrichment similarly influences PGCs and GCs, increasing survival of newborn Cells and transiently modulating GAD67 and plasticity-related molecules expression. However, PGC maturation appears to be delayed compared to GCs, reflecting a different temporal dynamic of adult generated olfactory interneuron integration. Moreover, olfactory enrichment or deprivation do not selectively modulate the survival of specific PGC phenotypes, supporting the idea that the integration rate of distinct PGC subtypes is independent from olfactory experience
Steven D. Munger - One of the best experts on this subject based on the ideXlab platform.
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Interglomerular pathways of the main olfactory bulb circuit.
2016Co-Authors: Cedric R. Uytingco, Adam C. Puche, Steven D. MungerAbstract:Schematic of the main olfactory bulb circuit with the (top) interglomerular-interneuron and (bottom) mitral-granule-mitral pathways highlighted. ONL, olfactory nerve layer; GL, glomerular layer; EPL, external plexiform layer; MCL, mitral Cell layer; IPL, internal plexiform layer; GrL, granule Cell layer; PG, Periglomerular Cell; SA, short axon Cell; ET, external tufted Cell; MC, mitral Cell; GC, granule Cell.
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Necklace glomeruli are not preferentially connected to other necklace glomeruli.
2016Co-Authors: Cedric R. Uytingco, Adam C. Puche, Steven D. MungerAbstract:(A) Schematic indicating stimulation of a central necklace glomerulus (NG) and ROIs (squares) taken from the neighboring canonical glomerulus (nCG, blue) and neighboring necklace glomerulus (nNG, green), and their respective EPL areas. ONL, olfactory nerve layer; GL, glomerular layer; EPL, external plexiform layer; MCL, mitral Cell layer; IPL, internal plexiform layer; GrL, granule Cell layer; PG, Periglomerular Cell; SA, short axon Cell; ET, external tufted Cell; MC, mitral Cell; GC, granule Cell. (B) Normalized signal peak from nNG (white) and nCG (gray), following individual necklace glomeruli stimulation. (C) Normalized mean signal peak from the EPL below the nNG and nCG.
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Lateral signal spread is dependent on the mitral-granule-mitral pathway.
2016Co-Authors: Cedric R. Uytingco, Adam C. Puche, Steven D. MungerAbstract:(A) Schematic of the MOB circuitry with EPL surgical microcut, and preservation of the interglomerular-interneuron pathway (red highlights). ONL, olfactory nerve layer; GL, glomerular layer; EPL, external plexiform layer; MCL, mitral Cell layer; IPL, internal plexiform layer; GrL, granule Cell layer; PG, Periglomerular Cell; SA, short axon Cell; ET, external tufted Cell; MC, mitral Cell; GC, granule Cell. (B) Fluorescence image of MOB slice indicating MOB layers, microcut location. Asterisk, tip of the stimulating electrode. Targeted glomerulus indicated by dashed circle. Representative point ROIs from neighboring rostral/caudal areas (squares). Scale bar = 400μm. (C) Overlaid pseudo-colored ΔF/F stimulus-dependent responses before (top) and during GBZ treatment (bottom) at 2.5s after stimulus initiation. (D and E) Mean signal peak of the (D) GL (F(2,12) = 8.32, p = 0.005, Bonferroni t-test, n = 7) and (E) EPL (F(2,12) = 14.85, p
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Lateral signal spread is dependent on interglomerular pathway.
2016Co-Authors: Cedric R. Uytingco, Adam C. Puche, Steven D. MungerAbstract:(A) Schematic of the MOB circuitry with GL surgical microcut, and preservation of the mitral-granule-mitral pathway (red highlights). ONL, olfactory nerve layer; GL, glomerular layer; EPL, external plexiform layer; MCL, mitral Cell layer; IPL, internal plexiform layer; GrL, granule Cell layer; PG, Periglomerular Cell; SA, short axon Cell; ET, external tufted Cell; MC, mitral Cell; GC, granule Cell. (B) Fluorescence image of MOB slice. Asterisk, tip of the stimulating electrode. Targeted glomerulus indicated by dashed circle. Representative point ROIs from neighboring rostral/caudal areas (squares). Scale bar = 400 μm. (C). Overlaid pseudo-colored ΔF/F stimulus-dependent responses before (top) and during (bottom) GBZ treatment at 2.5s after stimulus initiation. (D and E) Mean signal peak of the GL (D) (F(2,6) = 10.02, p = 0.012, Bonferroni t-test, n = 4) and EPL (E) (F(2,6) = 9.72, p = 0.013, Bonferroni t-test, n = 6) at 360 μm rostral (black) and 360 μm caudal (gray) of the stimulated glomerulus. (F and G) Normalized horizontal signal traces in the GL (F) and EPL (G), before (black) and during (red) GBZ treatment. (H and I) Mean FWHM signal spread in the GL (H) (F(2,5) = 7.2, p
J. Bakker - One of the best experts on this subject based on the ideXlab platform.
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Short term treatment with estradiol decreases the rate of newly generated Cells in the subventricular zone and main olfactory bulb of adult female mice
Neuroscience, 2010Co-Authors: O. Brock, Alexandra Veyrac, Matthieu Keller, Q. Douhard, J. BakkerAbstract:Adult neurogenesis occurs most notably in the subgranular zone (SGZ) of the hippocampal dentate gyrus and in the olfactory bulb (OB) where new neurons are generated from neural progenitors Cells produced in the subventricular zone (SVZ) of the forebrain. As it is well known that gonadal steroid hormones, primarily estradiol, modulate neurogenesis in the hippocampus of adult female rodents, we wanted to determine whether estradiol would also affect the proliferation of progenitor Cells in the SVZ and by consequence the rate of newly generated Cells in the main OB. Thus a first group of adult female C57B16/J mice was ovariectomized and received a short term treatment with estradiol (single injection of 1 or 10 mu g 17 beta-estradiol or Silastic capsule of estradiol during 2 days) before receiving a single injection with BrdU to determine whether estradiol would modulate the Cell proliferation in the SVZ. A second group of adult ovariectomized female mice was submitted to the same estradiol treatment before receiving four BrdU injections, and was sacrificed 21 days later to determine whether a modulation in Cell proliferation actually leads to a modulation in the number of newborn Cells in the main OB. We observed a decrease in Cell proliferation in the SVZ following either dose of estradiol compared to the controls. Furthermore, 21 days after their generation in the SVZ, the number of BrdU labeled Cells was also lower in the main OB, both in the granular and Periglomerular Cell layers of estradiol-treated animals. These results show that a short term treatment with estradiol actually downregulates Cell proliferation leading to a decreased number of newborn Cells in the OB. (C) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.