1
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Burton SD, Malyshko CM, Urban NN. Fast-spiking interneuron detonation drives high-fidelity inhibition in the olfactory bulb. PLoS Biol 2024; 22:e3002660. [PMID: 39186804 PMCID: PMC11379389 DOI: 10.1371/journal.pbio.3002660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 09/06/2024] [Accepted: 07/26/2024] [Indexed: 08/28/2024] Open
Abstract
Inhibitory circuits in the mammalian olfactory bulb (OB) dynamically reformat olfactory information as it propagates from peripheral receptors to downstream cortex. To gain mechanistic insight into how specific OB interneuron types support this sensory processing, we examine unitary synaptic interactions between excitatory mitral and tufted cells (MTCs), the OB projection neurons, and a conserved population of anaxonic external plexiform layer interneurons (EPL-INs) using pair and quartet whole-cell recordings in acute mouse brain slices. Physiological, morphological, neurochemical, and synaptic analyses divide EPL-INs into distinct subtypes and reveal that parvalbumin-expressing fast-spiking EPL-INs (FSIs) perisomatically innervate MTCs with release-competent dendrites and synaptically detonate to mediate fast, short-latency recurrent and lateral inhibition. Sparse MTC synchronization supralinearly increases this high-fidelity inhibition, while sensory afferent activation combined with single-cell silencing reveals that individual FSIs account for a substantial fraction of total network-driven MTC lateral inhibition. OB output is thus powerfully shaped by detonation-driven high-fidelity perisomatic inhibition.
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Affiliation(s)
- Shawn D Burton
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, United States of America
| | - Christina M Malyshko
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, United States of America
| | - Nathaniel N Urban
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, United States of America
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2
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Burton SD, Malyshko CM, Urban NN. Fast-spiking interneuron detonation drives high-fidelity inhibition in the olfactory bulb. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.07.592874. [PMID: 38766161 PMCID: PMC11100763 DOI: 10.1101/2024.05.07.592874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Inhibitory circuits in the mammalian olfactory bulb (OB) dynamically reformat olfactory information as it propagates from peripheral receptors to downstream cortex. To gain mechanistic insight into how specific OB interneuron types support this sensory processing, we examine unitary synaptic interactions between excitatory mitral and tufted cells (MTCs), the OB projection cells, and a conserved population of anaxonic external plexiform layer interneurons (EPL-INs) using pair and quartet whole-cell recordings in acute mouse brain slices. Physiological, morphological, neurochemical, and synaptic analyses divide EPL-INs into distinct subtypes and reveal that parvalbumin-expressing fast-spiking EPL-INs (FSIs) perisomatically innervate MTCs with release-competent dendrites and synaptically detonate to mediate fast, short-latency recurrent and lateral inhibition. Sparse MTC synchronization supralinearly increases this high-fidelity inhibition, while sensory afferent activation combined with single-cell silencing reveals that individual FSIs account for a substantial fraction of total network-driven MTC lateral inhibition. OB output is thus powerfully shaped by detonation-driven high-fidelity perisomatic inhibition.
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Affiliation(s)
- Shawn D. Burton
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, USA
| | | | - Nathaniel N. Urban
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, USA
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3
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Trejo DH, Ciuparu A, da Silva PG, Velasquez CM, Rebouillat B, Gross MD, Davis MB, Muresan RC, Albeanu DF. Fast updating feedback from piriform cortex to the olfactory bulb relays multimodal reward contingency signals during rule-reversal. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.12.557267. [PMID: 37745564 PMCID: PMC10515864 DOI: 10.1101/2023.09.12.557267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
While animals readily adjust their behavior to adapt to relevant changes in the environment, the neural pathways enabling these changes remain largely unknown. Here, using multiphoton imaging, we investigated whether feedback from the piriform cortex to the olfactory bulb supports such behavioral flexibility. To this end, we engaged head-fixed mice in a multimodal rule-reversal task guided by olfactory and auditory cues. Both odor and, surprisingly, the sound cues triggered cortical bulbar feedback responses which preceded the behavioral report. Responses to the same sensory cue were strongly modulated upon changes in stimulus-reward contingency (rule reversals). The re-shaping of individual bouton responses occurred within seconds of the rule-reversal events and was correlated with changes in the behavior. Optogenetic perturbation of cortical feedback within the bulb disrupted the behavioral performance. Our results indicate that the piriform-to-olfactory bulb feedback carries reward contingency signals and is rapidly re-formatted according to changes in the behavioral context.
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Affiliation(s)
| | - Andrei Ciuparu
- Transylvanian Institute of Neuroscience, Cluj-Napoca, Romania
| | - Pedro Garcia da Silva
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
- current address – Champalimaud Neuroscience Program, Lisbon, Portugal
| | - Cristina M. Velasquez
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
- current address – University of Oxford, UK
| | - Benjamin Rebouillat
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
- current address –École Normale Supérieure, Paris, France
| | | | | | - Raul C. Muresan
- Transylvanian Institute of Neuroscience, Cluj-Napoca, Romania
- STAR-UBB Institute, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Dinu F. Albeanu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
- School for Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
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4
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Maier JX, Zhang Z. Early development of olfactory circuit function. Front Cell Neurosci 2023; 17:1225186. [PMID: 37565031 PMCID: PMC10410114 DOI: 10.3389/fncel.2023.1225186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 06/29/2023] [Indexed: 08/12/2023] Open
Abstract
During early development, brains undergo profound changes in structure at the molecular, synaptic, cellular and circuit level. At the same time, brains need to perform adaptive function. How do structurally immature brains process information? How do brains perform stable and reliable function despite massive changes in structure? The rodent olfactory system presents an ideal model for approaching these poorly understood questions. Rodents are born deaf and blind, and rely completely on their sense of smell to acquire resources essential for survival during the first 2 weeks of life, such as food and warmth. Here, we review decades of work mapping structural changes in olfactory circuits during early development, as well as more recent studies performing in vivo electrophysiological recordings to characterize functional activity patterns generated by these circuits. The findings demonstrate that neonatal olfactory processing relies on an interacting network of brain areas including the olfactory bulb and piriform cortex. Circuits in these brain regions exhibit varying degrees of structural maturity in neonatal animals. However, despite substantial ongoing structural maturation of circuit elements, the neonatal olfactory system produces dynamic network-level activity patterns that are highly stable over protracted periods during development. We discuss how these findings inform future work aimed at elucidating the circuit-level mechanisms underlying information processing in the neonatal olfactory system, how they support unique neonatal behaviors, and how they transition between developmental stages.
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Affiliation(s)
- Joost X. Maier
- Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Winston-Salem, NC, United States
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5
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Mazo C, Nissant A, Saha S, Peroni E, Lledo PM, Lepousez G. Long-range GABAergic projections contribute to cortical feedback control of sensory processing. Nat Commun 2022; 13:6879. [PMID: 36371430 PMCID: PMC9653434 DOI: 10.1038/s41467-022-34513-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/25/2022] [Indexed: 11/15/2022] Open
Abstract
In the olfactory system, the olfactory cortex sends glutamatergic projections back to the first stage of olfactory processing, the olfactory bulb (OB). Such corticofugal excitatory circuits - a canonical circuit motif described in all sensory systems- dynamically adjust early sensory processing. Here, we uncover a corticofugal inhibitory feedback to OB, originating from a subpopulation of GABAergic neurons in the anterior olfactory cortex and innervating both local and output OB neurons. In vivo imaging and network modeling showed that optogenetic activation of cortical GABAergic projections drives a net subtractive inhibition of both spontaneous and odor-evoked activity in local as well as output neurons. In output neurons, stimulation of cortical GABAergic feedback enhances separation of population odor responses in tufted cells, but not mitral cells. Targeted pharmacogenetic silencing of cortical GABAergic axon terminals impaired discrimination of similar odor mixtures. Thus, corticofugal GABAergic projections represent an additional circuit motif in cortical feedback control of sensory processing.
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Affiliation(s)
- Camille Mazo
- Institut Pasteur, Université Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, Perception and Memory Unit, F-75015, Paris, France.
- Champalimaud Foundation, Lisbon, Portugal.
| | - Antoine Nissant
- Institut Pasteur, Université Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, Perception and Memory Unit, F-75015, Paris, France
| | - Soham Saha
- Institut Pasteur, Université Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, Perception and Memory Unit, F-75015, Paris, France
| | - Enzo Peroni
- Institut Pasteur, Université Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, Perception and Memory Unit, F-75015, Paris, France
| | - Pierre-Marie Lledo
- Institut Pasteur, Université Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, Perception and Memory Unit, F-75015, Paris, France.
| | - Gabriel Lepousez
- Institut Pasteur, Université Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, Perception and Memory Unit, F-75015, Paris, France.
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6
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Brunert D, Rothermel M. Extrinsic neuromodulation in the rodent olfactory bulb. Cell Tissue Res 2021; 383:507-524. [PMID: 33355709 PMCID: PMC7873007 DOI: 10.1007/s00441-020-03365-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/24/2020] [Indexed: 12/16/2022]
Abstract
Evolutionarily, olfaction is one of the oldest senses and pivotal for an individual's health and survival. The olfactory bulb (OB), as the first olfactory relay station in the brain, is known to heavily process sensory information. To adapt to an animal's needs, OB activity can be influenced by many factors either from within (intrinsic neuromodulation) or outside (extrinsic neuromodulation) the OB which include neurotransmitters, neuromodulators, hormones, and neuropeptides. Extrinsic sources seem to be of special importance as the OB receives massive efferent input from numerous brain centers even outweighing the sensory input from the nose. Here, we review neuromodulatory processes in the rodent OB from such extrinsic sources. We will discuss extrinsic neuromodulation according to points of origin, receptors involved, affected circuits, and changes in behavior. In the end, we give a brief outlook on potential future directions in research on neuromodulation in the OB.
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Affiliation(s)
- Daniela Brunert
- Department of Chemosensation, AG Neuromodulation, Institute for Biology II, RWTH Aachen University, 52074, Aachen, Germany
| | - Markus Rothermel
- Department of Chemosensation, AG Neuromodulation, Institute for Biology II, RWTH Aachen University, 52074, Aachen, Germany.
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7
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Stone MC, Kothe GO, Rolls MM, Jegla T. Cytoskeletal and synaptic polarity of LWamide-like+ ganglion neurons in the sea anemone Nematostella vectensis. J Exp Biol 2020; 223:jeb233197. [PMID: 32968001 PMCID: PMC7673360 DOI: 10.1242/jeb.233197] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/14/2020] [Indexed: 12/22/2022]
Abstract
The centralized nervous systems of bilaterian animals rely on directional signaling facilitated by polarized neurons with specialized axons and dendrites. It is not known whether axo-dendritic polarity is exclusive to bilaterians or was already present in early metazoans. We therefore examined neurite polarity in the starlet sea anemone Nematostella vectensis (Cnidaria). Cnidarians form a sister clade to bilaterians and share many neuronal building blocks characteristic of bilaterians, including channels, receptors and synaptic proteins, but their nervous systems comprise a comparatively simple net distributed throughout the body. We developed a tool kit of fluorescent polarity markers for live imaging analysis of polarity in an identified neuron type, large ganglion cells of the body column nerve net that express the LWamide-like neuropeptide. Microtubule polarity differs in bilaterian axons and dendrites, and this in part underlies polarized distribution of cargo to the two types of processes. However, in LWamide-like+ neurons, all neurites had axon-like microtubule polarity suggesting that they may have similar contents. Indeed, presynaptic and postsynaptic markers trafficked to all neurites and accumulated at varicosities where neurites from different neurons often crossed, suggesting the presence of bidirectional synaptic contacts. Furthermore, we could not identify a diffusion barrier in the plasma membrane of any of the neurites like the axon initial segment barrier that separates the axonal and somatodendritic compartments in bilaterian neurons. We conclude that at least one type of neuron in Nematostella vectensis lacks the axo-dendritic polarity characteristic of bilaterian neurons.
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Affiliation(s)
- Michelle C Stone
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Gregory O Kothe
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Melissa M Rolls
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Timothy Jegla
- Department of Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
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8
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Wu A, Yu B, Chen Q, Matthews GA, Lu C, Campbell E, Tye KM, Komiyama T. Context-dependent plasticity of adult-born neurons regulated by cortical feedback. SCIENCE ADVANCES 2020; 6:6/42/eabc8319. [PMID: 33067236 PMCID: PMC7567600 DOI: 10.1126/sciadv.abc8319] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 09/02/2020] [Indexed: 05/26/2023]
Abstract
In a complex and dynamic environment, the brain flexibly adjusts its circuits to preferentially process behaviorally relevant information. Here, we investigated how the olfactory bulb copes with this demand by examining the plasticity of adult-born granule cells (abGCs). We found that learning of olfactory discrimination elevates odor responses of young abGCs and increases their apical dendritic spines. This plasticity did not occur in abGCs during passive odor experience nor in resident granule cells (rGCs) during learning. Furthermore, we found that feedback projections from the piriform cortex show elevated activity during learning, and activating piriform feedback elicited stronger excitatory postsynaptic currents in abGCs than rGCs. Inactivation of piriform feedback blocked abGC plasticity during learning, and activation of piriform feedback during passive experience induced learning-like plasticity of abGCs. Our work describes a neural circuit mechanism that uses adult neurogenesis to update a sensory circuit to flexibly adapt to new behavioral demands.
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Affiliation(s)
- An Wu
- Neurobiology Section, and Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA 92093, USA.
- Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA
| | - Bin Yu
- Neurobiology Section, and Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA 92093, USA
- Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Qiyu Chen
- Neurobiology Section, and Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA 92093, USA
- Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA
| | | | - Chen Lu
- Neurobiology Section, and Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA 92093, USA
- Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA
| | - Evan Campbell
- Neurobiology Section, and Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA 92093, USA
| | - Kay M Tye
- Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Takaki Komiyama
- Neurobiology Section, and Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA 92093, USA.
- Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA
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9
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Imam N, Cleland TA. Rapid online learning and robust recall in a neuromorphic olfactory circuit. NAT MACH INTELL 2020; 2:181-191. [PMID: 38650843 PMCID: PMC11034913 DOI: 10.1038/s42256-020-0159-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 02/07/2020] [Indexed: 01/02/2023]
Abstract
We present a neural algorithm for the rapid online learning and identification of odourant samples under noise, based on the architecture of the mammalian olfactory bulb and implemented on the Intel Loihi neuromorphic system. As with biological olfaction, the spike timing-based algorithm utilizes distributed, event-driven computations and rapid (one-shot) online learning. Spike timing-dependent plasticity rules operate iteratively over sequential gamma-frequency packets to construct odour representations from the activity of chemosensor arrays mounted in a wind tunnel. Learned odourants then are reliably identified despite strong destructive interference. Noise resistance is further enhanced by neuromodulation and contextual priming. Lifelong learning capabilities are enabled by adult neurogenesis. The algorithm is applicable to any signal identification problem in which high-dimensional signals are embedded in unknown backgrounds.
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Affiliation(s)
- Nabil Imam
- Neuromorphic Computing Laboratory, Intel Corporation, San Francisco, CA 94111, USA
| | - Thomas A. Cleland
- Computational Physiology Laboratory, Dept. Psychology, Cornell University, Ithaca, NY 14853, USA
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10
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Wu A, Yu B, Komiyama T. Plasticity in olfactory bulb circuits. Curr Opin Neurobiol 2020; 64:17-23. [PMID: 32062045 DOI: 10.1016/j.conb.2020.01.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 11/27/2019] [Accepted: 01/15/2020] [Indexed: 12/24/2022]
Abstract
Olfaction is crucial for animal survival and human well-being. The olfactory bulb is the obligatory input station for olfactory information. In contrast to the traditional view as a static relay station, recent evidence indicates that the olfactory bulb dynamically processes olfactory information in an experience-dependent and context-dependent manner. Here, we review recent studies on experience-dependent plasticity of the main circuit components within the olfactory bulb of rodents. We argue that the olfactory bulb plasticity allows optimal representations of behaviorally-relevant odors in the continuously changing olfactory environment.
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Affiliation(s)
- An Wu
- Neurobiology Section, Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA 92093, USA; Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Bin Yu
- Neurobiology Section, Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA 92093, USA; Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Takaki Komiyama
- Neurobiology Section, Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA 92093, USA; Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA.
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11
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Shan L, Liu T, Zhang Z, Liu Q, Zhang M, Zhao X, Zhang Y, Xu F, Ma Y. Schizophrenia-like olfactory dysfunction induced by acute and postnatal phencyclidine exposure in rats. Schizophr Res 2018; 199:274-280. [PMID: 29510924 DOI: 10.1016/j.schres.2018.02.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 02/22/2018] [Accepted: 02/25/2018] [Indexed: 10/17/2022]
Abstract
Deficits in olfactory abilities are frequently observed in schizophrenia patients. However, whether olfactory dysfunction is found in animal models is not known. Here, we examined whether two well-established schizophrenia rat models exhibit olfactory-relevant dysfunction that is similar to schizophrenia patients. Olfactory sensitivity was tested in rats that were acutely (3.3mg/kg) or postnatally (10mg/kg, at postnatal day 7, 9 and 11) treated with phencyclidine (PCP) as schizophrenia models. Electrophysiological recordings were conducted to measure the olfactory-relevant local field potential after acute PCP treatment. Olfactory-relevant neural connections were tested via virus tracing in rats postnatally treated with PCP. We also assessed the reversal effects of olanzapine (OLZ) treatment on both models. We found that acute PCP treatment induced a decline in olfactory sensitivity (p=0.01) and significantly lower beta- and higher gamma-band oscillations (p=0.03, and p=0.00 respectively) which were partly attenuated by OLZ treatment (2mg/kg and 4mg/kg). Postnatal PCP exposure also resulted in an olfactory sensitivity deficit during adulthood (p=0.012 for males and p=0.009 for females), and an abnormal development of neural circuits (p=0.000). Together, our research indicated that olfactory dysfunction found in schizophrenia patients can also be observed on animal models.
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Affiliation(s)
- Liang Shan
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Tiane Liu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhijian Zhang
- Wuhan Institute of Physics and Mathematics, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Qing Liu
- Wuhan Institute of Physics and Mathematics, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Mengjiao Zhang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xudong Zhao
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yan Zhang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Fuqiang Xu
- Wuhan Institute of Physics and Mathematics, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Wuhan 430071, China; Wuhan National Laboratory for Optoelectronics, Wuhan 430074, China
| | - Yuanye Ma
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Yunnan Key Laboratory of Primate Biomedicine Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China.
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12
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Wienisch M, Murthy VN. Population imaging at subcellular resolution supports specific and local inhibition by granule cells in the olfactory bulb. Sci Rep 2016; 6:29308. [PMID: 27388949 PMCID: PMC4937346 DOI: 10.1038/srep29308] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/09/2016] [Indexed: 11/24/2022] Open
Abstract
Information processing in early sensory regions is modulated by a diverse range of inhibitory interneurons. We sought to elucidate the role of olfactory bulb interneurons called granule cells (GCs) in odor processing by imaging the activity of hundreds of these cells simultaneously in mice. Odor responses in GCs were temporally diverse and spatially disperse, with some degree of non-random, modular organization. The overall sparseness of activation of GCs was highly correlated with the extent of glomerular activation by odor stimuli. Increasing concentrations of single odorants led to proportionately larger population activity, but some individual GCs had non-monotonic relations to concentration due to local inhibitory interactions. Individual dendritic segments could sometimes respond independently to odors, revealing their capacity for compartmentalized signaling in vivo. Collectively, the response properties of GCs point to their role in specific and local processing, rather than global operations such as response normalization proposed for other interneurons.
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Affiliation(s)
- Martin Wienisch
- Center for Brain Science and Department of Molecular &Cellular Biology Harvard University, Cambridge 02138, MA, USA
| | - Venkatesh N Murthy
- Center for Brain Science and Department of Molecular &Cellular Biology Harvard University, Cambridge 02138, MA, USA
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13
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Sun T, Li T, Davies H, Li W, Yang J, Li S, Ling S. Altered Morphologies and Functions of the Olfactory Bulb and Hippocampus Induced by miR-30c. Front Neurosci 2016; 10:207. [PMID: 27242411 PMCID: PMC4860400 DOI: 10.3389/fnins.2016.00207] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 04/25/2016] [Indexed: 11/17/2022] Open
Abstract
Adult neurogenesis is considered to contribute to a certain degree of plasticity for the brain. However, the effects of adult-born neurons on the brain are still largely unknown. Here, we specifically altered the expression of miR-30c in the subventricular zone (SVZ) and dentate gyrus (DG) by stereotaxic injection with their respective up- and down-regulated lentiviruses. Results showed an increased level of miR-30c enhanced adult neurogenesis by prompting cell-cycles of stem cells, whereas down-regulated miR-30c led to the opposite results. When these effects of miR-30c lasted for 3 months, we detected significant morphological changes in the olfactory bulb (OB) and lineage alteration in the hippocampus. Tests of olfactory sensitivity and associative and spatial memory showed that a certain amount of adult-born neurons are essential for the normal functions of the OB and hippocampus, but there also exist redundant newborn neurons that do not further improve the functioning of these areas. Our study revealed the interactions between miRNA, adult neurogenesis, brain morphology and function, and this provides a novel insight into understanding the role of newborn neurons in the adult brain.
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Affiliation(s)
- Tingting Sun
- Institute of Neuroscience and Anatomy, Zhejiang University School of Medicine Hangzhou, China
| | - Tianpeng Li
- College of Environment Science and Engineering, Donghua University Shanghai, China
| | - Henry Davies
- Institute of Neuroscience, Zhejiang University School of Medicine Hangzhou, China
| | - Weiyun Li
- Institute of Neuroscience and Anatomy, Zhejiang University School of Medicine Hangzhou, China
| | - Jing Yang
- Institute of Neuroscience and Anatomy, Zhejiang University School of Medicine Hangzhou, China
| | - Shanshan Li
- Institute of Neuroscience and Anatomy, Zhejiang University School of Medicine Hangzhou, China
| | - Shucai Ling
- Institute of Neuroscience and Anatomy, Zhejiang University School of Medicine Hangzhou, China
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14
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Abstract
Polarized distribution of signaling molecules to axons and dendrites facilitates directional information flow in complex vertebrate nervous systems. The topic we address here is when the key aspects of neuronal polarity evolved. All neurons have a central cell body with thin processes that extend from it to cover long distances, and they also all rely on voltage-gated ion channels to propagate signals along their length. The most familiar neurons, those in vertebrates, have additional cellular features that allow them to send directional signals efficiently. In these neurons, dendrites typically receive signals and axons send signals. It has been suggested that many of the distinct features of axons and dendrites, including the axon initial segment, are found only in vertebrates. However, it is now becoming clear that two key cytoskeletal features that underlie polarized sorting, a specialized region at the base of the axon and polarized microtubules, are found in invertebrate neurons as well. It thus seems likely that all bilaterians generate axons and dendrites in the same way. As a next step, it will be extremely interesting to determine whether the nerve nets of cnidarians and ctenophores also contain polarized neurons with true axons and dendrites, or whether polarity evolved in concert with the more centralized nervous systems found in bilaterians.
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Affiliation(s)
- Melissa M Rolls
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Timothy J Jegla
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
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15
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Duménieu M, Fourcaud-Trocmé N, Garcia S, Kuczewski N. Afterhyperpolarization (AHP) regulates the frequency and timing of action potentials in the mitral cells of the olfactory bulb: role of olfactory experience. Physiol Rep 2015; 3:3/5/e12344. [PMID: 26019289 PMCID: PMC4463813 DOI: 10.14814/phy2.12344] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Afterhyperpolarization (AHP) is a principal feedback mechanism in the control of the frequency and patterning of neuronal firing. In principal projection neurons of the olfactory bulb, the mitral cells (MCs), the AHP is produced by three separate components: classical potassium-mediated hyperpolarization, and the excitatory and inhibitory components, which are generated by the recurrent dendrodendritic synaptic transmission. Precise spike timing is involved in olfactory coding and learning, as well as in the appearance of population oscillatory activity. However, the contribution of the AHP and its components to these processes remains unknown. In this study, we demonstrate that the AHP is developed with the MC firing frequency and is dominated by the potassium component. We also show that recurrent synaptic transmission significantly modifies MC AHP and that the strength of the hyperpolarization produced by the AHP in the few milliseconds preceding the action potential (AP) emission determines MC firing frequency and AP timing. Moreover, we show that the AHP area is larger in younger animals, possibly owing to increased Ca2+ influx during MC firing. Finally, we show that olfactory experience selectively reduces the early component of the MC AHP (under 25 msec), thus producing a modification of the AP timing limited to the higher firing frequency. On the basis of these results, we propose that the AHP, and its susceptibility to be selectively modulated by the recurrent synaptic transmission and olfactory experience, participate in odor coding and learning by modifying the frequency and pattern of MC firing.
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Affiliation(s)
- Maël Duménieu
- Centre de Recherche en Neurosciences de Lyon, INSERM U1028/CNRS UMR5292, Université Lyon1, Lyon, France
| | - Nicolas Fourcaud-Trocmé
- Centre de Recherche en Neurosciences de Lyon, INSERM U1028/CNRS UMR5292, Université Lyon1, Lyon, France
| | - Samuel Garcia
- Centre de Recherche en Neurosciences de Lyon, INSERM U1028/CNRS UMR5292, Université Lyon1, Lyon, France
| | - Nicola Kuczewski
- Centre de Recherche en Neurosciences de Lyon, INSERM U1028/CNRS UMR5292, Université Lyon1, Lyon, France
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16
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Soria-Gomez E, Bellocchio L, Marsicano G. New insights on food intake control by olfactory processes: the emerging role of the endocannabinoid system. Mol Cell Endocrinol 2014; 397:59-66. [PMID: 25261796 DOI: 10.1016/j.mce.2014.09.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/22/2014] [Accepted: 09/22/2014] [Indexed: 01/06/2023]
Abstract
The internal state of the organism is an important modulator of perception and behavior. The link between hunger, olfaction and feeding behavior is one of the clearest examples of these connections. At the neurobiological level, olfactory circuits are the targets of several signals (i.e. hormones and nutrients) involved in energy balance. This indicates that olfactory areas are potential sensors of the internal state of the organism. Thus, the aim of this manuscript is to review the literature showing the interplay between metabolic signals in olfactory circuits and its impact on food intake.
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Affiliation(s)
- Edgar Soria-Gomez
- INSERM, U862 NeuroCentre Magendie, Endocannabinoids and Neuroadaptation, Bordeaux, France.
| | - Luigi Bellocchio
- Dept. of Biochemistry and Molecular Biology I, Sch. of Biology, Complutense Univ. and CIBERNED, Madrid, Spain
| | - Giovanni Marsicano
- INSERM, U862 NeuroCentre Magendie, Endocannabinoids and Neuroadaptation, Bordeaux, France
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17
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Abstract
The ability of organisms to seamlessly ignore familiar, inconsequential stimuli improves their selective attention and response to salient features of the environment. Here, I propose that this fundamental but unexplained phenomenon substantially derives from the ability of any pattern of neural excitation to create an enhanced inhibitory (or "negative") image of itself through target-specific scaling of inhibitory inputs onto active excitatory neurons. Familiar stimuli encounter strong negative images and are therefore less likely to be transmitted to higher brain centers. Integrating historical and recent observations, the negative-image model described here provides a mechanistic framework for understanding habituation, which is connected to ideas on dynamic predictive coding. In addition, it suggests insights for understanding autism spectrum disorders.
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18
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Tong MT, Peace ST, Cleland TA. Properties and mechanisms of olfactory learning and memory. Front Behav Neurosci 2014; 8:238. [PMID: 25071492 PMCID: PMC4083347 DOI: 10.3389/fnbeh.2014.00238] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 06/16/2014] [Indexed: 02/05/2023] Open
Abstract
Memories are dynamic physical phenomena with psychometric forms as well as characteristic timescales. Most of our understanding of the cellular mechanisms underlying the neurophysiology of memory, however, derives from one-trial learning paradigms that, while powerful, do not fully embody the gradual, representational, and statistical aspects of cumulative learning. The early olfactory system—particularly olfactory bulb—comprises a reasonably well-understood and experimentally accessible neuronal network with intrinsic plasticity that underlies both one-trial (adult aversive, neonatal) and cumulative (adult appetitive) odor learning. These olfactory circuits employ many of the same molecular and structural mechanisms of memory as, for example, hippocampal circuits following inhibitory avoidance conditioning, but the temporal sequences of post-conditioning molecular events are likely to differ owing to the need to incorporate new information from ongoing learning events into the evolving memory trace. Moreover, the shapes of acquired odor representations, and their gradual transformation over the course of cumulative learning, also can be directly measured, adding an additional representational dimension to the traditional metrics of memory strength and persistence. In this review, we describe some established molecular and structural mechanisms of memory with a focus on the timecourses of post-conditioning molecular processes. We describe the properties of odor learning intrinsic to the olfactory bulb and review the utility of the olfactory system of adult rodents as a memory system in which to study the cellular mechanisms of cumulative learning.
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Affiliation(s)
- Michelle T Tong
- Computational Physiology Lab, Department of Psychology, Cornell University Ithaca, NY, USA
| | - Shane T Peace
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA
| | - Thomas A Cleland
- Computational Physiology Lab, Department of Psychology, Cornell University Ithaca, NY, USA
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19
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Rothermel M, Wachowiak M. Functional imaging of cortical feedback projections to the olfactory bulb. Front Neural Circuits 2014; 8:73. [PMID: 25071454 PMCID: PMC4080262 DOI: 10.3389/fncir.2014.00073] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/12/2014] [Indexed: 11/16/2022] Open
Abstract
Processing of sensory information is substantially shaped by centrifugal, or feedback, projections from higher cortical areas, yet the functional properties of these projections are poorly characterized. Here, we used genetically-encoded calcium sensors (GCaMPs) to functionally image activation of centrifugal projections targeting the olfactory bulb (OB). The OB receives massive centrifugal input from cortical areas but there has been as yet no characterization of their activity in vivo. We focused on projections to the OB from the anterior olfactory nucleus (AON), a major source of cortical feedback to the OB. We expressed GCaMP selectively in AON projection neurons using a mouse line expressing Cre recombinase (Cre) in these neurons and Cre-dependent viral vectors injected into AON, allowing us to image GCaMP fluorescence signals from their axon terminals in the OB. Electrical stimulation of AON evoked large fluorescence signals that could be imaged from the dorsal OB surface in vivo. Surprisingly, odorants also evoked large signals that were transient and coupled to odorant inhalation both in the anesthetized and awake mouse, suggesting that feedback from AON to the OB is rapid and robust across different brain states. The strength of AON feedback signals increased during wakefulness, suggesting a state-dependent modulation of cortical feedback to the OB. Two-photon GCaMP imaging revealed that different odorants activated different subsets of centrifugal AON axons and could elicit both excitation and suppression in different axons, indicating a surprising richness in the representation of odor information by cortical feedback to the OB. Finally, we found that activating neuromodulatory centers such as basal forebrain drove AON inputs to the OB independent of odorant stimulation. Our results point to the AON as a multifunctional cortical area that provides ongoing feedback to the OB and also serves as a descending relay for other neuromodulatory systems.
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Affiliation(s)
- Markus Rothermel
- Brain Institute and Department of Neurobiology and Anatomy, University of Utah Salt Lake City, UT, USA
| | - Matt Wachowiak
- Brain Institute and Department of Neurobiology and Anatomy, University of Utah Salt Lake City, UT, USA
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20
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Patterson MA, Lagier S, Carleton A. Odor representations in the olfactory bulb evolve after the first breath and persist as an odor afterimage. Proc Natl Acad Sci U S A 2013; 110:E3340-9. [PMID: 23918364 PMCID: PMC3761593 DOI: 10.1073/pnas.1303873110] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Rodents can discriminate odors in one breath, and mammalian olfaction research has thus focused on the first breath. However, sensory representations dynamically change during and after stimuli. To investigate these dynamics, we recorded spike trains from the olfactory bulb of awake, head-fixed mice and found that some mitral cells' odor representations changed following the first breath and others continued after odor cessation. Population analysis revealed that these postodor responses contained odor- and concentration-specific information--an odor afterimage. Using calcium imaging, we found that most olfactory glomerular activity was restricted to the odor presentation, implying that the afterimage is not primarily peripheral. The odor afterimage was not dependent on odorant physicochemical properties. To artificially induce aftereffects, we photostimulated mitral cells using channelrhodopsin and recorded centrally maintained persistent activity. The strength and persistence of the afterimage was dependent on the duration of both artificial and natural stimulation. In summary, we show that the odor representation evolves after the first breath and that there is a centrally maintained odor afterimage, similar to other sensory systems. These dynamics may help identify novel odorants in complex environments.
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Affiliation(s)
- Michael Andrew Patterson
- Department of Basic Neurosciences, School of Medicine, University of Geneva, CH-1211 Geneva 4, Switzerland; and
- Geneva Neuroscience Center, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Samuel Lagier
- Department of Basic Neurosciences, School of Medicine, University of Geneva, CH-1211 Geneva 4, Switzerland; and
- Geneva Neuroscience Center, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Alan Carleton
- Department of Basic Neurosciences, School of Medicine, University of Geneva, CH-1211 Geneva 4, Switzerland; and
- Geneva Neuroscience Center, University of Geneva, CH-1211 Geneva 4, Switzerland
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21
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Shao Z, Puche AC, Shipley MT. Intraglomerular inhibition maintains mitral cell response contrast across input frequencies. J Neurophysiol 2013; 110:2185-91. [PMID: 23926045 DOI: 10.1152/jn.00023.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Odor signals are transmitted to the olfactory bulb by olfactory nerve (ON) synapses onto mitral/tufted cells (MTCs) and external tufted cells (ETCs); ETCs provide additional feed-forward excitation to MTCs. Both are strongly regulated by intraglomerular inhibition that can last up to 1 s and, when blocked, dramatically increases ON-evoked MC spiking. Intraglomerular inhibition thus limits the magnitude and duration of MC spike responses to sensory input. In vivo, sensory input is repetitive, dictated by sniffing rates from 1 to 8 Hz, potentially summing intraglomerular inhibition. To investigate this, we recorded MTC responses to 1- to 8-Hz ON stimulation in slices. Inhibitory postsynaptic current area (charge) following each ON stimulation was unchanged from 1 to 5 Hz and modestly paired-pulse attenuated at 8 Hz, suggesting there is no summation and only limited decrement at the highest input frequencies. Next, we investigated frequency independence of intraglomerular inhibition on MC spiking. MCs respond to single ON shocks with an initial spike burst followed by reduced spiking decaying to baseline. Upon repetitive ON stimulation peak spiking is identical across input frequencies but the ratio of peak-to-minimum rate before the stimulus (max-min) diminishes from 30:1 at 1 Hz to 15:1 at 8 Hz. When intraglomerular inhibition is selectively blocked, peak spike rate is unchanged but trough spiking increases markedly decreasing max-min firing ratios from 30:1 at 1 Hz to 2:1 at 8 Hz. Together, these results suggest intraglomerular inhibition is relatively frequency independent and can "sharpen" MC responses to input across the range of frequencies. This suggests that glomerular circuits can maintain "contrast" in MC encoding during sniff-sampled inputs.
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Affiliation(s)
- Zuoyi Shao
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland
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22
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Gire DH, Restrepo D, Sejnowski TJ, Greer C, De Carlos JA, Lopez-Mascaraque L. Temporal processing in the olfactory system: can we see a smell? Neuron 2013; 78:416-32. [PMID: 23664611 PMCID: PMC3694266 DOI: 10.1016/j.neuron.2013.04.033] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/24/2013] [Indexed: 10/26/2022]
Abstract
Sensory processing circuits in the visual and olfactory systems receive input from complex, rapidly changing environments. Although patterns of light and plumes of odor create different distributions of activity in the retina and olfactory bulb, both structures use what appears on the surface similar temporal coding strategies to convey information to higher areas in the brain. We compare temporal coding in the early stages of the olfactory and visual systems, highlighting recent progress in understanding the role of time in olfactory coding during active sensing by behaving animals. We also examine studies that address the divergent circuit mechanisms that generate temporal codes in the two systems, and find that they provide physiological information directly related to functional questions raised by neuroanatomical studies of Ramon y Cajal over a century ago. Consideration of differences in neural activity in sensory systems contributes to generating new approaches to understand signal processing.
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Affiliation(s)
- David H Gire
- Molecular and Cellular Biology, and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
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23
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Morrison GL, Fontaine CJ, Harley CW, Yuan Q. A role for the anterior piriform cortex in early odor preference learning: evidence for multiple olfactory learning structures in the rat pup. J Neurophysiol 2013; 110:141-52. [PMID: 23576704 DOI: 10.1152/jn.00072.2013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
cFos activation in the anterior piriform cortex (aPC) occurs in early odor preference learning in rat pups (Roth and Sullivan 2005). Here we provide evidence that the pairing of odor as a conditioned stimulus and β-adrenergic activation in the aPC as an unconditioned stimulus generates early odor preference learning. β-Adrenergic blockade in the aPC prevents normal preference learning. Enhancement of aPC cAMP response element-binding protein (CREB) phosphorylation in trained hemispheres is consistent with a role for this cascade in early odor preference learning in the aPC. In vitro experiments suggested theta-burst-mediated long-term potentiation (LTP) at the lateral olfactory tract (LOT) to aPC synapse depends on N-methyl-D-aspartate (NMDA) receptors and can be significantly enhanced by β-adrenoceptor activation, which causes increased glutamate release from LOT synapses during LTP induction. NMDA receptors in aPC are also shown to be critical for the acquisition, but not expression, of odor preference learning, as would be predicted if they mediate initial β-adrenoceptor-promoted aPC plasticity. Ex vivo experiments 3 and 24 h after odor preference training reveal an enhanced LOT-aPC field excitatory postsynaptic potential (EPSP). At 3 h both presynaptic and postsynaptic potentiations support EPSP enhancement while at 24 h only postsynaptic potentiation is seen. LOT-LTP in aPC is excluded by odor preference training. Taken together with earlier work on the role of the olfactory bulb in early odor preference learning, these outcomes suggest early odor preference learning is normally supported by and requires multiple plastic changes at least at two levels of olfactory circuitry.
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Affiliation(s)
- Gillian L Morrison
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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24
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Functional properties of cortical feedback projections to the olfactory bulb. Neuron 2013; 76:1175-88. [PMID: 23259952 DOI: 10.1016/j.neuron.2012.10.028] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2012] [Indexed: 11/22/2022]
Abstract
Sensory perception is not a simple feed-forward process, and higher brain areas can actively modulate information processing in "lower" areas. We used optogenetic methods to examine how cortical feedback projections affect circuits in the first olfactory processing stage, the olfactory bulb. Selective activation of back projections from the anterior olfactory nucleus/cortex (AON) revealed functional glutamatergic synaptic connections on several types of bulbar interneurons. Unexpectedly, AON axons also directly depolarized mitral cells (MCs), enough to elicit spikes reliably in a time window of a few milliseconds. MCs received strong disynaptic inhibition, a third of which arises in the glomerular layer. Activating feedback axons in vivo suppressed spontaneous as well as odor-evoked activity of MCs, sometimes preceded by a temporally precise increase in firing probability. Our study indicates that cortical feedback can shape the activity of bulbar output neurons by enabling precisely timed spikes and enforcing broad inhibition to suppress background activity.
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25
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Boyd AM, Sturgill JF, Poo C, Isaacson JS. Cortical feedback control of olfactory bulb circuits. Neuron 2012; 76:1161-74. [PMID: 23259951 PMCID: PMC3725136 DOI: 10.1016/j.neuron.2012.10.020] [Citation(s) in RCA: 195] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2012] [Indexed: 12/29/2022]
Abstract
Olfactory cortex pyramidal cells integrate sensory input from olfactory bulb mitral and tufted (M/T) cells and project axons back to the bulb. However, the impact of cortical feedback projections on olfactory bulb circuits is unclear. Here, we selectively express channelrhodopsin-2 in olfactory cortex pyramidal cells and show that cortical feedback projections excite diverse populations of bulb interneurons. Activation of cortical fibers directly excites GABAergic granule cells, which in turn inhibit M/T cells. However, we show that cortical inputs preferentially target short axon cells that drive feedforward inhibition of granule cells. In vivo, activation of olfactory cortex that only weakly affects spontaneous M/T cell firing strongly gates odor-evoked M/T cell responses: cortical activity suppresses odor-evoked excitation and enhances odor-evoked inhibition. Together, these results indicate that although cortical projections have diverse actions on olfactory bulb microcircuits, the net effect of cortical feedback on M/T cells is an amplification of odor-evoked inhibition.
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Affiliation(s)
- Alison M. Boyd
- Center for Neural Circuits and Behavior, Department of Neuroscience, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
| | - James F. Sturgill
- Center for Neural Circuits and Behavior, Department of Neuroscience, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
| | - Cindy Poo
- Center for Neural Circuits and Behavior, Department of Neuroscience, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
| | - Jeffry S. Isaacson
- Center for Neural Circuits and Behavior, Department of Neuroscience, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
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26
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Niedworok C, Schwarz I, Ledderose J, Giese G, Conzelmann KK, Schwarz M. Charting Monosynaptic Connectivity Maps by Two-Color Light-Sheet Fluorescence Microscopy. Cell Rep 2012; 2:1375-86. [DOI: 10.1016/j.celrep.2012.10.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 08/30/2012] [Accepted: 10/11/2012] [Indexed: 01/09/2023] Open
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27
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Bölinger D, Gollisch T. Closed-loop measurements of iso-response stimuli reveal dynamic nonlinear stimulus integration in the retina. Neuron 2012; 73:333-46. [PMID: 22284187 DOI: 10.1016/j.neuron.2011.10.039] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2011] [Indexed: 11/28/2022]
Abstract
Neurons often integrate information from multiple parallel signaling streams. How a neuron combines these inputs largely determines its computational role in signal processing. Experimental assessment of neuronal signal integration, however, is often confounded by cell-intrinsic nonlinear processes that arise after signal integration has taken place. To overcome this problem and determine how ganglion cells in the salamander retina integrate visual contrast over space, we used automated online analysis of recorded spike trains and closed-loop control of the visual stimuli to identify different stimulus patterns that give the same neuronal response. These iso-response stimuli revealed a threshold-quadratic transformation as a fundamental nonlinearity within the receptive field center. Moreover, for a subset of ganglion cells, the method revealed an additional dynamic nonlinearity that renders these cells particularly sensitive to spatially homogeneous stimuli. This function is shown to arise from a local inhibition-mediated dynamic gain control mechanism.
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Affiliation(s)
- Daniel Bölinger
- Max Planck Institute of Neurobiology, Visual Coding Group, 82152 Martinsried, Germany
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28
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Shao Z, Puche AC, Liu S, Shipley MT. Intraglomerular inhibition shapes the strength and temporal structure of glomerular output. J Neurophysiol 2012; 108:782-93. [PMID: 22592311 DOI: 10.1152/jn.00119.2012] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Odor signals are transmitted to the olfactory bulb by olfactory nerve (ON) synapses onto mitral/tufted cells (MCs) and external tufted cells (ETCs). ETCs, in turn, provide feedforward excitatory input to MCs. MC and ETCs are also regulated by inhibition: intraglomerular and interglomerular inhibitory circuits act at MC and ETC apical dendrites; granule cells (GCs) inhibit MC lateral dendrites via the MC→GC→MC circuit. We investigated the contribution of intraglomerular inhibition to MC and ETCs responses to ON input. ON input evokes initial excitation followed by early, strongly summating inhibitory postsynaptic currents (IPSCs) in MCs; this is followed by prolonged, intermittent IPSCs. The N-methyl-d-aspartate receptor antagonist dl-amino-5-phosphovaleric acid, known to suppress GABA release by GCs, reduced late IPSCs but had no effect on early IPSCs. In contrast, selective intraglomerular block of GABA(A) receptors eliminated all early IPSCs and caused a 5-fold increase in ON-evoked MC spiking and a 10-fold increase in response duration. ETCs also receive intraglomerular inhibition; blockade of inhibition doubled ETC spike responses. By reducing ETC excitatory drive and directly inhibiting MCs, intraglomerular inhibition is a key factor shaping the strength and temporal structure of MC responses to sensory input. Sensory input generates an intraglomerular excitation-inhibition sequence that limits MC spike output to a brief temporal window. Glomerular circuits may dynamically regulate this input-output window to optimize MC encoding across sniff-sampled inputs.
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Affiliation(s)
- Zuoyi Shao
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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29
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Girardin CC, Galizia CG. The "Where" and "Who" in Brain Science: Probing Brain Networks with Local Perturbations. Cognit Comput 2012. [DOI: 10.1007/s12559-011-9122-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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30
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Abstract
Sensation is an active process involving the sampling and central processing of external stimuli selectively in space and time. Olfaction in particular depends strongly on active sensing due to the fact that-at least in mammals-inhalation of air into the nasal cavity is required for odor detection. This seemingly simple first step in odor sensation profoundly shapes nearly all aspects of olfactory system function, from the distribution of odorant receptors to the functional organization of central processing to the perception of odors. The dependence of olfaction on inhalation also allows for profound modulation of olfactory processing by changes in odor sampling strategies in coordination with attentional state and sensory demands. This review discusses the role of active sensing in shaping olfactory system function at multiple levels and draws parallels with other sensory modalities to highlight the importance of an active sensing perspective in understanding how sensory systems work in the behaving animal.
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Affiliation(s)
- Matt Wachowiak
- Department of Physiology and Brain Institute, University of Utah, Salt Lake City, UT 84103, USA.
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31
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Brain-state-independent neural representation of peripheral stimulation in rat olfactory bulb. Proc Natl Acad Sci U S A 2011; 108:5087-92. [PMID: 21321196 DOI: 10.1073/pnas.1013814108] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It is critical for normal brains to perceive the external world precisely and accurately under ever-changing operational conditions, yet the mechanisms underlying this fundamental brain function in the sensory systems are poorly understood. To address this issue in the olfactory system, we investigated the responses of olfactory bulbs to odor stimulations under different brain states manipulated by anesthesia levels. Our results revealed that in two brain states, where the spontaneous baseline activities differed about twofold based on the local field potential (LFP) signals, the levels of neural activities reached after the same odor stimulation had no significant difference. This phenomenon was independent of anesthetics (pentobarbital or chloral hydrate), stimulating odorants (ethyl propionate, ethyl butyrate, ethyl valerate, amyl acetate, n-heptanal, or 2-heptanone), odor concentrations, and recording sites (the mitral or granular cell layers) for LFPs in three frequency bands (12-32 Hz, 33-64 Hz, and 65-90 Hz) and for multiunit activities. Furthermore, the activity patterns of the same stimulation under these two brain states were highly similar at both LFP and multiunit levels. These converging results argue the existence of mechanisms in the olfactory bulbs that ensure the delivery of peripheral olfactory information to higher olfactory centers with high fidelity under different brain states.
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32
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Lazarini F, Lledo PM. Is adult neurogenesis essential for olfaction? Trends Neurosci 2011; 34:20-30. [DOI: 10.1016/j.tins.2010.09.006] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 09/14/2010] [Accepted: 09/23/2010] [Indexed: 12/31/2022]
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33
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Cardona A, Saalfeld S, Preibisch S, Schmid B, Cheng A, Pulokas J, Tomancak P, Hartenstein V. An integrated micro- and macroarchitectural analysis of the Drosophila brain by computer-assisted serial section electron microscopy. PLoS Biol 2010; 8:e1000502. [PMID: 20957184 PMCID: PMC2950124 DOI: 10.1371/journal.pbio.1000502] [Citation(s) in RCA: 200] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 08/19/2010] [Indexed: 11/18/2022] Open
Abstract
The analysis of microcircuitry (the connectivity at the level of individual neuronal processes and synapses), which is indispensable for our understanding of brain function, is based on serial transmission electron microscopy (TEM) or one of its modern variants. Due to technical limitations, most previous studies that used serial TEM recorded relatively small stacks of individual neurons. As a result, our knowledge of microcircuitry in any nervous system is very limited. We applied the software package TrakEM2 to reconstruct neuronal microcircuitry from TEM sections of a small brain, the early larval brain of Drosophila melanogaster. TrakEM2 enables us to embed the analysis of the TEM image volumes at the microcircuit level into a light microscopically derived neuro-anatomical framework, by registering confocal stacks containing sparsely labeled neural structures with the TEM image volume. We imaged two sets of serial TEM sections of the Drosophila first instar larval brain neuropile and one ventral nerve cord segment, and here report our first results pertaining to Drosophila brain microcircuitry. Terminal neurites fall into a small number of generic classes termed globular, varicose, axiform, and dendritiform. Globular and varicose neurites have large diameter segments that carry almost exclusively presynaptic sites. Dendritiform neurites are thin, highly branched processes that are almost exclusively postsynaptic. Due to the high branching density of dendritiform fibers and the fact that synapses are polyadic, neurites are highly interconnected even within small neuropile volumes. We describe the network motifs most frequently encountered in the Drosophila neuropile. Our study introduces an approach towards a comprehensive anatomical reconstruction of neuronal microcircuitry and delivers microcircuitry comparisons between vertebrate and insect neuropile.
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Affiliation(s)
- Albert Cardona
- Institute of Neuroinformatics, ETH/University of Zürich, Zürich, Switzerland
| | - Stephan Saalfeld
- Max Plank Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Stephan Preibisch
- Max Plank Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Benjamin Schmid
- Lehrstuhl für Genetik und Neurobiologie, University of Würzburg, Würzburg, Germany
| | - Anchi Cheng
- Automated Molecular Imaging Group, The Scripps Research Institute (TSRI), San Diego, California, United States of America
| | - Jim Pulokas
- Automated Molecular Imaging Group, The Scripps Research Institute (TSRI), San Diego, California, United States of America
| | - Pavel Tomancak
- Max Plank Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Volker Hartenstein
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
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Abstract
The stimulus complexity of naturally occurring odours presents unique challenges for central nervous systems that are aiming to internalize the external olfactory landscape. One mechanism by which the brain encodes perceptual representations of behaviourally relevant smells is through the synthesis of different olfactory inputs into a unified perceptual experience--an odour object. Recent evidence indicates that the identification, categorization and discrimination of olfactory stimuli rely on the formation and modulation of odour objects in the piriform cortex. Convergent findings from human and rodent models suggest that distributed piriform ensemble patterns of olfactory qualities and categories are crucial for maintaining the perceptual constancy of ecologically inconstant stimuli.
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35
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Isaacson JS. Odor representations in mammalian cortical circuits. Curr Opin Neurobiol 2010; 20:328-31. [PMID: 20207132 DOI: 10.1016/j.conb.2010.02.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 02/03/2010] [Indexed: 11/30/2022]
Abstract
Spatial and temporal activity patterns of olfactory bulb projection neurons underlie the initial representations of odors in the brain. However, olfactory perception ultimately requires the integration of olfactory bulb output in higher cortical brain regions. Recent studies reveal that odor representations are sparse and highly distributed in the rodent primary olfactory (piriform) cortex. Furthermore, odor-evoked inhibition is far more widespread and broadly tuned than excitation in piriform cortex pyramidal cells. Other recent studies highlight how olfactory sensory inputs are integrated within pyramidal cell dendrites and that feedback projections from piriform cortex to olfactory bulb interneurons are a source of synaptic plasticity.
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Affiliation(s)
- Jeffry S Isaacson
- Center for Neural Circuits and Behavior, Dept. of Neuroscience, University of California, San Diego, La Jolla, 92093, USA.
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36
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Mouret A, Murray K, Lledo PM. Centrifugal Drive onto Local Inhibitory Interneurons of the Olfactory Bulb. Ann N Y Acad Sci 2009; 1170:239-54. [DOI: 10.1111/j.1749-6632.2009.03913.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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