1
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Vogler NW, Chen R, Virkler A, Tu VY, Gottfried JA, Geffen MN. Direct piriform-to-auditory cortical projections shape auditory-olfactory integration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.11.602976. [PMID: 39071445 PMCID: PMC11275881 DOI: 10.1101/2024.07.11.602976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
In a real-world environment, the brain must integrate information from multiple sensory modalities, including the auditory and olfactory systems. However, little is known about the neuronal circuits governing how odors influence and modulate sound processing. Here, we investigated the mechanisms underlying auditory-olfactory integration using anatomical, electrophysiological, and optogenetic approaches, focusing on the auditory cortex as a key locus for cross-modal integration. First, retrograde and anterograde viral tracing strategies revealed a direct projection from the piriform cortex to the auditory cortex. Next, using in vivo electrophysiological recordings of neuronal activity in the auditory cortex of awake mice, we found that odor stimuli modulate auditory cortical responses to sound. Finally, we used in vivo optogenetic manipulations during electrophysiology to demonstrate that olfactory modulation in auditory cortex, specifically, odor-driven enhancement of sound responses, depends on direct input from the piriform cortex. Together, our results identify a novel cortical circuit shaping olfactory modulation in the auditory cortex, shedding new light on the neuronal mechanisms underlying auditory-olfactory integration.
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Affiliation(s)
- Nathan W. Vogler
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania
| | - Ruoyi Chen
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania
| | - Alister Virkler
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania
| | - Violet Y. Tu
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania
| | - Jay A. Gottfried
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania
| | - Maria N. Geffen
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania
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2
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Chen Z, Padmanabhan K. Adult-neurogenesis allows for representational stability and flexibility in early olfactory system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.02.601573. [PMID: 39005290 PMCID: PMC11244980 DOI: 10.1101/2024.07.02.601573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
In the early olfactory system, adult-neurogenesis, a process of neuronal replacement results in the continuous reorganization of synaptic connections and network architecture throughout the animal's life. This poses a critical challenge: How does the olfactory system maintain stable representations of odors and therefore allow for stable sensory perceptions amidst this ongoing circuit instability? Utilizing a detailed spiking network model of early olfactory circuits, we uncovered dual roles for adult-neurogenesis: one that both supports representational stability to faithfully encode odor information and also one that facilitates plasticity to allow for learning and adaptation. In the main olfactory bulb, adult-neurogenesis affects neural codes in individual mitral and tufted cells but preserves odor representations at the neuronal population level. By contrast, in the olfactory piriform cortex, both individual cell responses and overall population dynamics undergo progressive changes due to adult-neurogenesis. This leads to representational drift, a gradual alteration in sensory perception. Both processes are dynamic and depend on experience such that repeated exposure to specific odors reduces the drift due to adult-neurogenesis; thus, when the odor environment is stable over the course of adult-neurogenesis, it is neurogenesis that actually allows the representations to remain stable in piriform cortex; when those olfactory environments change, adult-neurogenesis allows the cortical representations to track environmental change. Whereas perceptual stability and plasticity due to learning are often thought of as two distinct, often contradictory processing in neuronal coding, we find that adult-neurogenesis serves as a shared mechanism for both. In this regard, the quixotic presence of adult-neurogenesis in the mammalian olfactory bulb that has been the focus of considerable debate in chemosensory neuroscience may be the mechanistic underpinning behind an array of complex computations.
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Affiliation(s)
- Zhen Chen
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY14627
| | - Krishnan Padmanabhan
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642
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3
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Wang DC, Santos-Valencia F, Song JH, Franks KM, Luo L. Embryonically active piriform cortex neurons promote intracortical recurrent connectivity during development. Neuron 2024:S0896-6273(24)00414-8. [PMID: 38964330 DOI: 10.1016/j.neuron.2024.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 04/28/2024] [Accepted: 06/11/2024] [Indexed: 07/06/2024]
Abstract
Neuronal activity plays a critical role in the maturation of circuits that propagate sensory information into the brain. How widely does early activity regulate circuit maturation across the developing brain? Here, we used targeted recombination in active populations (TRAP) to perform a brain-wide survey for prenatally active neurons in mice and identified the piriform cortex as an abundantly TRAPed region. Whole-cell recordings in neonatal slices revealed preferential interconnectivity within embryonically TRAPed piriform neurons and their enhanced synaptic connectivity with other piriform neurons. In vivo Neuropixels recordings in neonates demonstrated that embryonically TRAPed piriform neurons exhibit broad functional connectivity within piriform and lead spontaneous synchronized population activity during a transient neonatal period, when recurrent connectivity is strengthening. Selectively activating or silencing these neurons in neonates enhanced or suppressed recurrent synaptic strength, respectively. Thus, embryonically TRAPed piriform neurons represent an interconnected hub-like population whose activity promotes recurrent connectivity in early development.
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Affiliation(s)
- David C Wang
- Howard Hughes Medical Institute and Department of Biology, Stanford University, Stanford, CA 94305, USA; Stanford MSTP, Stanford, CA 94305, USA
| | | | - Jun H Song
- Howard Hughes Medical Institute and Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Kevin M Franks
- Department of Neurobiology, Duke University School of Medicine, Durham, NC 27710, USA.
| | - Liqun Luo
- Howard Hughes Medical Institute and Department of Biology, Stanford University, Stanford, CA 94305, USA.
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4
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Ye Y, Wang Y, Zhuang Y, Tan H, Zuo Z, Yun H, Yuan K, Zhou W. Decomposition of an odorant in olfactory perception and neural representation. Nat Hum Behav 2024; 8:1150-1162. [PMID: 38499771 DOI: 10.1038/s41562-024-01849-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 02/19/2024] [Indexed: 03/20/2024]
Abstract
Molecules-the elementary units of substances-are commonly considered the units of processing in olfactory perception, giving rise to undifferentiated odour objects invariant to environmental variations. By selectively perturbing the processing of chemical substructures with adaptation ('the psychologist's microelectrode') in a series of psychophysical and neuroimaging experiments (458 participants), we show that two perceptually distinct odorants sharing part of their structural features become significantly less discernible following adaptation to a third odorant containing their non-shared structural features, in manners independent of olfactory intensity, valence, quality or general olfactory adaptation. The effect is accompanied by reorganizations of ensemble activity patterns in the posterior piriform cortex that parallel subjective odour quality changes, in addition to substructure-based neural adaptations in the anterior piriform cortex and amygdala. Central representations of odour quality and the perceptual outcome thus embed submolecular structural information and are malleable by recent olfactory encounters.
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Affiliation(s)
- Yuting Ye
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- Institute of Psychology, School of Public Affairs, Xiamen University, Xiamen, China
| | - Yanqing Wang
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- School of Psychology, Northwest Normal University, Lanzhou, China
| | - Yuan Zhuang
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Huibang Tan
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Zhentao Zuo
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, China
- Sino-Dannish College, University of Chinese Academy of Sciences, Beijing, China
| | - Hanqi Yun
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Kaiqi Yuan
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Wen Zhou
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
- Chinese Institute for Brain Research, Beijing, China.
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5
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Saxon D, Alderman PJ, Sorrells SF, Vicini S, Corbin JG. Neuronal Subtypes and Connectivity of the Adult Mouse Paralaminar Amygdala. eNeuro 2024; 11:ENEURO.0119-24.2024. [PMID: 38811163 PMCID: PMC11208988 DOI: 10.1523/eneuro.0119-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/03/2024] [Accepted: 05/10/2024] [Indexed: 05/31/2024] Open
Abstract
The paralaminar nucleus of the amygdala (PL) comprises neurons that exhibit delayed maturation. PL neurons are born during gestation but mature during adolescent ages, differentiating into excitatory neurons. These late-maturing PL neurons contribute to the increase in size and cell number of the amygdala between birth and adulthood. However, the function of the PL upon maturation is unknown, as the region has only recently begun to be characterized in detail. In this study, we investigated key defining features of the adult mouse PL; the intrinsic morpho-electric properties of its neurons, and its input and output circuit connectivity. We identify two subtypes of excitatory neurons in the PL based on unsupervised clustering of electrophysiological properties. These subtypes are defined by differential action potential firing properties and dendritic architecture, suggesting divergent functional roles. We further uncover major axonal inputs to the adult PL from the main olfactory network and basolateral amygdala. We also find that axonal outputs from the PL project reciprocally to these inputs and to diverse targets including the amygdala, frontal cortex, hippocampus, hypothalamus, and brainstem. Thus, the adult mouse PL is centrally placed to play a major role in the integration of olfactory sensory information, to coordinate affective and autonomic behavioral responses to salient odor stimuli.
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Affiliation(s)
- David Saxon
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC 20011
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20007
| | - Pia J Alderman
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Shawn F Sorrells
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Stefano Vicini
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20007
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20007
| | - Joshua G Corbin
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC 20011
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Mooziri M, Samii Moghaddam A, Mirshekar MA, Raoufy MR. Olfactory bulb-medial prefrontal cortex theta synchronization is associated with anxiety. Sci Rep 2024; 14:12101. [PMID: 38802558 PMCID: PMC11130310 DOI: 10.1038/s41598-024-63101-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 05/24/2024] [Indexed: 05/29/2024] Open
Abstract
Anxiety is among the most fundamental mammalian behaviors. Despite the physiological and pathological importance, its underlying neural mechanisms remain poorly understood. Here, we recorded the activity of olfactory bulb (OB) and medial prefrontal cortex (mPFC) of rats, which are critical structures to brain's emotional processing network, while exploring different anxiogenic environments. Our results show that presence in anxiogenic contexts increases the OB and mPFC regional theta activities. Also, these local activity changes are associated with enhanced OB-mPFC theta power- and phase-based functional connectivity as well as OB-to-mPFC information transfer. Interestingly, these effects are more prominent in the unsafe zones of the anxiogenic environments, compared to safer zones. This consistent trend of changes in diverse behavioral environments as well as local and long-range neural activity features suggest that the dynamics of OB-mPFC circuit theta oscillations might underlie different types of anxiety behaviors, with possible implications for anxiety disorders.
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Affiliation(s)
- Morteza Mooziri
- Student Research Committee, Zahedan University of Medical Sciences, Zahedan, Iran
- School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
- Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Ali Samii Moghaddam
- Student Research Committee, Zahedan University of Medical Sciences, Zahedan, Iran
- School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Mohammad Ali Mirshekar
- Clinical Immunology Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.
- Department of Physiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.
| | - Mohammad Reza Raoufy
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
- Institute for Brain Sciences and Cognition, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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7
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Yamaguchi M. Connectivity of the olfactory tubercle: inputs, outputs, and their plasticity. Front Neural Circuits 2024; 18:1423505. [PMID: 38841557 PMCID: PMC11150588 DOI: 10.3389/fncir.2024.1423505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 05/07/2024] [Indexed: 06/07/2024] Open
Abstract
The olfactory tubercle (OT) is a unique part of the olfactory cortex of the mammal brain in that it is also a component of the ventral striatum. It is crucially involved in motivational behaviors, particularly in adaptive olfactory learning. This review introduces the basic properties of the OT, its synaptic connectivity with other brain areas, and the plasticity of the connectivity associated with learning behavior. The adaptive properties of olfactory behavior are discussed further based on the characteristics of OT neuronal circuits.
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Affiliation(s)
- Masahiro Yamaguchi
- Department of Physiology, Kochi Medical School, Kochi University, Kochi, Japan
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8
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Wang J, Yang Q, Liu X, Li J, Wen YL, Hu Y, Xu TL, Duan S, Xu H. The basal forebrain to lateral habenula circuitry mediates social behavioral maladaptation. Nat Commun 2024; 15:4013. [PMID: 38740778 DOI: 10.1038/s41467-024-48378-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 04/29/2024] [Indexed: 05/16/2024] Open
Abstract
Elucidating the neural basis of fear allows for more effective treatments for maladaptive fear often observed in psychiatric disorders. Although the basal forebrain (BF) has an essential role in fear learning, its function in fear expression and the underlying neuronal and circuit substrates are much less understood. Here we report that BF glutamatergic neurons are robustly activated by social stimulus following social fear conditioning in male mice. And cell-type-specific inhibition of those excitatory neurons largely reduces social fear expression. At the circuit level, BF glutamatergic neurons make functional contacts with the lateral habenula (LHb) neurons and these connections are potentiated in conditioned mice. Moreover, optogenetic inhibition of BF-LHb glutamatergic pathway significantly reduces social fear responses. These data unravel an important function of the BF in fear expression via its glutamatergic projection onto the LHb, and suggest that selective targeting BF-LHb excitatory circuitry could alleviate maladaptive fear in relevant disorders.
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Affiliation(s)
- Jun Wang
- Department of Neurobiology and Department of Psychiatry of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China.
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, 1369 West Wenyi Road, Hangzhou, 311121, China.
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, 310058, China.
| | - Qian Yang
- Department of Neurobiology and Department of Psychiatry of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Xue Liu
- Department of Neurobiology and Department of Psychiatry of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- Lingang Laboratory, Shanghai, 200031, China
| | - Jie Li
- Department of Neurobiology and Department of Psychiatry of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Ya-Lan Wen
- Department of Neurobiology and Department of Psychiatry of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yuzheng Hu
- Department of Psychology and Behavioral Sciences, Zhejiang University, Hangzhou, 310027, China
| | - Tian-Le Xu
- Center for Brain Science and Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Shumin Duan
- Department of Neurobiology and Department of Psychiatry of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, 1369 West Wenyi Road, Hangzhou, 311121, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, 310058, China
| | - Han Xu
- Department of Neurobiology and Department of Psychiatry of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China.
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, 1369 West Wenyi Road, Hangzhou, 311121, China.
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, 310058, China.
- Lingang Laboratory, Shanghai, 200031, China.
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9
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Cai L, Argunşah AÖ, Damilou A, Karayannis T. A nasal chemosensation-dependent critical window for somatosensory development. Science 2024; 384:652-660. [PMID: 38723089 DOI: 10.1126/science.adn5611] [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: 12/15/2023] [Accepted: 04/05/2024] [Indexed: 05/31/2024]
Abstract
Nasal chemosensation is considered the evolutionarily oldest mammalian sense and, together with somatosensation, is crucial for neonatal well-being before auditory and visual pathways start engaging the brain. Using anatomical and functional approaches in mice, we reveal that odor-driven activity propagates to a large part of the cortex during the first postnatal week and enhances whisker-evoked activation of primary whisker somatosensory cortex (wS1). This effect disappears in adult animals, in line with the loss of excitatory connectivity from olfactory cortex to wS1. By performing neonatal odor deprivation, followed by electrophysiological and behavioral work in adult animals, we identify a key transient regulation of nasal chemosensory information necessary for the development of wS1 sensory-driven dynamics and somatosensation. Our work uncovers a cross-modal critical window for nasal chemosensation-dependent somatosensory functional maturation.
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Affiliation(s)
- Linbi Cai
- Laboratory of Neural Circuit Assembly, Brain Research Institute (HiFo), University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
- Neuroscience Center Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Ali Özgür Argunşah
- Laboratory of Neural Circuit Assembly, Brain Research Institute (HiFo), University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
- Neuroscience Center Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Angeliki Damilou
- Laboratory of Neural Circuit Assembly, Brain Research Institute (HiFo), University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
- Neuroscience Center Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Theofanis Karayannis
- Laboratory of Neural Circuit Assembly, Brain Research Institute (HiFo), University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
- Neuroscience Center Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
- University Research Priority Program (URPP), Adaptive Brain Circuits in Development and Learning (AdaBD), University of Zurich, CH-8057 Zurich, Switzerland
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10
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Wang DC, Santos-Valencia F, Song JH, Franks KM, Luo L. Embryonically Active Piriform Cortex Neurons Promote Intracortical Recurrent Connectivity during Development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.593265. [PMID: 38766173 PMCID: PMC11100831 DOI: 10.1101/2024.05.08.593265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Neuronal activity plays a critical role in the maturation of circuits that propagate sensory information into the brain. How widely does early activity regulate circuit maturation across the developing brain? Here, we used Targeted Recombination in Active Populations (TRAP) to perform a brain-wide survey for prenatally active neurons in mice and identified the piriform cortex as an abundantly TRAPed region. Whole-cell recordings in neonatal slices revealed preferential interconnectivity within embryonically TRAPed piriform neurons and their enhanced synaptic connectivity with other piriform neurons. In vivo Neuropixels recordings in neonates demonstrated that embryonically TRAPed piriform neurons exhibit broad functional connectivity within piriform and lead spontaneous synchronized population activity during a transient neonatal period, when recurrent connectivity is strengthening. Selectively activating or silencing of these neurons in neonates enhanced or suppressed recurrent synaptic strength, respectively. Thus, embryonically TRAPed piriform neurons represent an interconnected hub-like population whose activity promotes recurrent connectivity in early development.
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11
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Kundu S, Paul B, Reuevni I, Lamprecht R, Barkai E. Learning-induced bidirectional enhancement of inhibitory synaptic metaplasticity. J Physiol 2024; 602:2343-2358. [PMID: 38654583 DOI: 10.1113/jp284761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 04/02/2024] [Indexed: 04/26/2024] Open
Abstract
Training rodents in a particularly difficult olfactory-discrimination (OD) task results in the acquisition of the ability to perform the task well, termed 'rule learning'. In addition to enhanced intrinsic excitability and synaptic excitation in piriform cortex pyramidal neurons, rule learning results in increased synaptic inhibition across the whole cortical network to the point where it precisely maintains the balance between inhibition and excitation. The mechanism underlying such precise inhibitory enhancement remains to be explored. Here, we use brain slices from transgenic mice (VGAT-ChR2-EYFP), enabling optogenetic stimulation of single GABAergic neurons and recordings of unitary synaptic events in pyramidal neurons. Quantal analysis revealed that learning-induced enhanced inhibition is mediated by increased quantal size of the evoked inhibitory events. Next, we examined the plasticity of synaptic inhibition induced by long-lasting, intrinsically evoked spike firing in post-synaptic neurons. Repetitive depolarizing current pulses from depolarized (-70 mV) or hyperpolarized (-90 mV) membrane potentials induced long-term depression (LTD) and long-term potentiation (LTP) of synaptic inhibition, respectively. We found a profound bidirectional increase in the ability to induce both LTD, mediated by L-type calcium channels, and LTP, mediated by R-type calcium channels after rule learning. Blocking the GABAB receptor reversed the effect of intrinsic stimulation at -90 mV from LTP to LTD. We suggest that learning greatly enhances the ability to modify the strength of synaptic inhibition of principal neurons in both directions. Such plasticity of synaptic plasticity allows fine-tuning of inhibition on each particular neuron, thereby stabilizing the network while maintaining the memory of the rule. KEY POINTS: Olfactory discrimination rule learning results in long-lasting enhancement of synaptic inhibition on piriform cortex pyramidal neurons. Quantal analysis of unitary inhibitory synaptic events, evoked by optogenetic minimal stimulation, revealed that enhanced synaptic inhibition is mediated by increased quantal size. Surprisingly, metaplasticity of synaptic inhibition, induced by intrinsically evoked repetitive spike firing, is increased bidirectionally. The susceptibility to both long-term depression (LTD) and long-term potentiation (LTP) of inhibition is enhanced after learning. LTD of synaptic inhibition is mediated by L-type calcium channels and LTP by R-type calcium channels. LTP is also dependent on activation of GABAB receptors. We suggest that learning-induced changes in the metaplasticity of synaptic inhibition enable the fine-tuning of inhibition on each particular neuron, thereby stabilizing the network while maintaining the memory of the rule.
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Affiliation(s)
- Sankhanava Kundu
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Blesson Paul
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Iris Reuevni
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Raphael Lamprecht
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Edi Barkai
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
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12
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Fang S, Luo Z, Wei Z, Qin Y, Zheng J, Zhang H, Jin J, Li J, Miao C, Yang S, Li Y, Liang Z, Yu XD, Zhang XM, Xiong W, Zhu H, Gan WB, Huang L, Li B. Sexually dimorphic control of affective state processing and empathic behaviors. Neuron 2024; 112:1498-1517.e8. [PMID: 38430912 DOI: 10.1016/j.neuron.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/08/2023] [Accepted: 02/01/2024] [Indexed: 03/05/2024]
Abstract
Recognizing the affective states of social counterparts and responding appropriately fosters successful social interactions. However, little is known about how the affective states are expressed and perceived and how they influence social decisions. Here, we show that male and female mice emit distinct olfactory cues after experiencing distress. These cues activate distinct neural circuits in the piriform cortex (PiC) and evoke sexually dimorphic empathic behaviors in observers. Specifically, the PiC → PrL pathway is activated in female observers, inducing a social preference for the distressed counterpart. Conversely, the PiC → MeA pathway is activated in male observers, evoking excessive self-grooming behaviors. These pathways originate from non-overlapping PiC neuron populations with distinct gene expression signatures regulated by transcription factors and sex hormones. Our study unveils how internal states of social counterparts are processed through sexually dimorphic mechanisms at the molecular, cellular, and circuit levels and offers insights into the neural mechanisms underpinning sex differences in higher brain functions.
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Affiliation(s)
- Shunchang Fang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Zhengyi Luo
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Zicheng Wei
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Yuxin Qin
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Jieyan Zheng
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Hongyang Zhang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Jianhua Jin
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Jiali Li
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Chenjian Miao
- Institute on Aging, Hefei, China and Brain Disorders, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Shana Yang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Yonglin Li
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Zirui Liang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Xiao-Dan Yu
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Xiao Min Zhang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Wei Xiong
- Institute on Aging, Hefei, China and Brain Disorders, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Hongying Zhu
- Institute on Aging, Hefei, China and Brain Disorders, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | | | - Lianyan Huang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China; Key Laboratory of Human Microbiome and Chronic Diseases (Sun Yat-Sen University), Ministry of Education, Guangzhou 510655, China.
| | - Boxing Li
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China; Key Laboratory of Human Microbiome and Chronic Diseases (Sun Yat-Sen University), Ministry of Education, Guangzhou 510655, China.
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13
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A Dehaqani A, Michelon F, Patella P, Petrucco L, Piasini E, Iurilli G. A mechanosensory feedback that uncouples external and self-generated sensory responses in the olfactory cortex. Cell Rep 2024; 43:114013. [PMID: 38551962 DOI: 10.1016/j.celrep.2024.114013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/20/2023] [Accepted: 03/13/2024] [Indexed: 04/28/2024] Open
Abstract
Sampling behaviors have sensory consequences that can hinder perceptual stability. In olfaction, sniffing affects early odor encoding, mimicking a sudden change in odor concentration. We examined how the inhalation speed affects the representation of odor concentration in the main olfactory cortex. Neurons combine the odor input with a global top-down signal preceding the sniff and a mechanosensory feedback generated by the air passage through the nose during inhalation. Still, the population representation of concentration is remarkably sniff invariant. This is because the mechanosensory and olfactory responses are uncorrelated within and across neurons. Thus, faster odor inhalation and an increase in concentration change the cortical activity pattern in distinct ways. This encoding strategy affords tolerance to potential concentration fluctuations caused by varying inhalation speeds. Since mechanosensory reafferences are widespread across sensory systems, the coding scheme described here may be a canonical strategy to mitigate the sensory ambiguities caused by movements.
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Affiliation(s)
- Alireza A Dehaqani
- Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy; CIMeC, University of Trento, 38068 Rovereto, Italy
| | - Filippo Michelon
- Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy; CIMeC, University of Trento, 38068 Rovereto, Italy
| | - Paola Patella
- Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy
| | - Luigi Petrucco
- Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy
| | - Eugenio Piasini
- International School for Advanced Studies (SISSA), Trieste, Italy
| | - Giuliano Iurilli
- Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy.
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14
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Zak JD, Reddy G, Konanur V, Murthy VN. Distinct information conveyed to the olfactory bulb by feedforward input from the nose and feedback from the cortex. Nat Commun 2024; 15:3268. [PMID: 38627390 PMCID: PMC11021479 DOI: 10.1038/s41467-024-47366-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 03/29/2024] [Indexed: 04/19/2024] Open
Abstract
Sensory systems are organized hierarchically, but feedback projections frequently disrupt this order. In the olfactory bulb (OB), cortical feedback projections numerically match sensory inputs. To unravel information carried by these two streams, we imaged the activity of olfactory sensory neurons (OSNs) and cortical axons in the mouse OB using calcium indicators, multiphoton microscopy, and diverse olfactory stimuli. Here, we show that odorant mixtures of increasing complexity evoke progressively denser OSN activity, yet cortical feedback activity is of similar sparsity for all stimuli. Also, representations of complex mixtures are similar in OSNs but are decorrelated in cortical axons. While OSN responses to increasing odorant concentrations exhibit a sigmoidal relationship, cortical axonal responses are complex and nonmonotonic, which can be explained by a model with activity-dependent feedback inhibition in the cortex. Our study indicates that early-stage olfactory circuits have access to local feedforward signals and global, efficiently formatted information about odor scenes through cortical feedback.
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Affiliation(s)
- Joseph D Zak
- Department of Biological Sciences, University of Illinois Chicago, Chicago, IL, 60607, USA.
- Department of Psychology, University of Illinois Chicago, Chicago, IL, 60607, USA.
| | - Gautam Reddy
- Physics & Informatics Laboratories, NTT Research, Inc., Sunnyvale, CA, 94085, USA
- Department of Physics, Princeton University, Princeton, NJ, 08540, USA
- Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA
| | - Vaibhav Konanur
- Department of Biological Sciences, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Venkatesh N Murthy
- Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
- Kempner Institute for the Study of Natural and Artificial Intelligence, Harvard University, Allston, 02134, USA
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15
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Deloulme JC, Leclercq M, Deschaux O, Flore G, Capellano L, Tocco C, Braz BY, Studer M, Lahrech H. Structural interhemispheric connectivity defects in mouse models of BBSOAS: Insights from high spatial resolution 3D white matter tractography. Neurobiol Dis 2024; 193:106455. [PMID: 38408685 DOI: 10.1016/j.nbd.2024.106455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/23/2024] [Accepted: 02/23/2024] [Indexed: 02/28/2024] Open
Abstract
White matter (WM) tract formation and axonal pathfinding are major processes in brain development allowing to establish precise connections between targeted structures. Disruptions in axon pathfinding and connectivity impairments will lead to neural circuitry abnormalities, often associated with various neurodevelopmental disorders (NDDs). Among several neuroimaging methodologies, Diffusion Tensor Imaging (DTI) is a magnetic resonance imaging (MRI) technique that has the advantage of visualizing in 3D the WM tractography of the whole brain non-invasively. DTI is particularly valuable in unpinning structural tract connectivity defects of neural networks in NDDs. In this study, we used 3D DTI to unveil brain-specific tract defects in two mouse models lacking the Nr2f1 gene, which mutations in patients have been proven to cause an emerging NDD, called Bosch-Boonstra-Schaaf Optic Atrophy (BBSOAS). We aimed to investigate the impact of the lack of cortical Nr2f1 function on WM morphometry and tract microstructure quantifications. We found in both mutant mice partial loss of fibers and severe misrouting of the two major cortical commissural tracts, the corpus callosum, and the anterior commissure, as well as the two major hippocampal efferent tracts, the post-commissural fornix, and the ventral hippocampal commissure. DTI tract malformations were supported by 2D histology, 3D fluorescent imaging, and behavioral analyses. We propose that these interhemispheric connectivity impairments are consistent in explaining some cognitive defects described in BBSOAS patients, particularly altered information processing between the two brain hemispheres. Finally, our results highlight 3DDTI as a relevant neuroimaging modality that can provide appropriate morphometric biomarkers for further diagnosis of BBSOAS patients.
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Affiliation(s)
| | | | - Olivier Deschaux
- University Côte d'Azur (UCA), CNRS, Inserm, Institute of Biology Valrose (iBV), Nice, France
| | - Gemma Flore
- Institute of Genetics and Biophysics "Adriano Buzzati Traverso", CNR, Napoli, Italy
| | - Laetitia Capellano
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institute Neurosciences, 38000 Grenoble, France
| | - Chiara Tocco
- University Côte d'Azur (UCA), CNRS, Inserm, Institute of Biology Valrose (iBV), Nice, France
| | - Barbara Yael Braz
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institute Neurosciences, 38000 Grenoble, France
| | - Michèle Studer
- University Côte d'Azur (UCA), CNRS, Inserm, Institute of Biology Valrose (iBV), Nice, France.
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16
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Hu Y, Du W, Qi J, Luo H, Zhang Z, Luo M, Wang Y. Comparative brain-wide mapping of ketamine- and isoflurane-activated nuclei and functional networks in the mouse brain. eLife 2024; 12:RP88420. [PMID: 38512722 PMCID: PMC10957177 DOI: 10.7554/elife.88420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024] Open
Abstract
Ketamine (KET) and isoflurane (ISO) are two widely used general anesthetics, yet their distinct and shared neurophysiological mechanisms remain elusive. In this study, we conducted a comparative analysis of the effects of KET and ISO on c-Fos expression across the mouse brain, utilizing hierarchical clustering and c-Fos-based functional network analysis to evaluate the responses of individual brain regions to each anesthetic. Our findings reveal that KET activates a wide range of brain regions, notably in the cortical and subcortical nuclei involved in sensory, motor, emotional, and reward processing, with the temporal association areas (TEa) as a strong hub, suggesting a top-down mechanism affecting consciousness by primarily targeting higher order cortical networks. In contrast, ISO predominantly influences brain regions in the hypothalamus, impacting neuroendocrine control, autonomic function, and homeostasis, with the locus coeruleus (LC) as a connector hub, indicating a bottom-up mechanism in anesthetic-induced unconsciousness. KET and ISO both activate brain areas involved in sensory processing, memory and cognition, reward and motivation, as well as autonomic and homeostatic control, highlighting their shared effects on various neural pathways. In conclusion, our results highlight the distinct but overlapping effects of KET and ISO, enriching our understanding of the mechanisms underlying general anesthesia.
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Affiliation(s)
- Yue Hu
- Department of Anesthesiology, Huashan Hospital, Fudan UniversityShanghaiChina
| | - Wenjie Du
- Department of Anesthesiology, Huashan Hospital, Fudan UniversityShanghaiChina
| | - Jiangtao Qi
- Department of Anesthesiology, Huashan Hospital, Fudan UniversityShanghaiChina
| | - Huoqing Luo
- School of Life Science and Technology, ShanghaiTech UniversityShanghaiChina
| | - Zhao Zhang
- Department of Anesthesiology, Huashan Hospital, Fudan UniversityShanghaiChina
| | - Mengqiang Luo
- Department of Anesthesiology, Huashan Hospital, Fudan UniversityShanghaiChina
| | - Yingwei Wang
- Department of Anesthesiology, Huashan Hospital, Fudan UniversityShanghaiChina
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17
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Saxon D, Alderman PJ, Sorrells SF, Vicini S, Corbin JG. Neuronal subtypes and connectivity of the adult mouse paralaminar amygdala. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.11.575250. [PMID: 38260244 PMCID: PMC10802617 DOI: 10.1101/2024.01.11.575250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The paralaminar nucleus of the amygdala (PL) is comprised of neurons which exhibit delayed maturation. PL neurons are born during gestation but mature during adolescent ages, differentiating into excitatory neurons. The PL is prominent in the adult amygdala, contributing to its increased neuron number and relative size compared to childhood. However, the function of the PL is unknown, as the region has only recently begun to be characterized in detail. In this study, we investigated key defining features of the adult PL; the intrinsic morpho-electric properties of its neurons, and its input and output connectivity. We identify two subtypes of excitatory neurons in the PL based on unsupervised clustering of electrophysiological properties. These subtypes are defined by differential action potential firing properties and dendritic architecture, suggesting divergent functional roles. We further uncover major axonal inputs to the adult PL from the main olfactory network and basolateral amygdala. We also find that axonal outputs from the PL project reciprocally to major inputs, and to diverse targets including the amygdala, frontal cortex, hippocampus, hypothalamus, and brainstem. Thus, the adult PL is centrally placed to play a major role in the integration of olfactory sensory information, likely coordinating affective and autonomic behavioral responses to salient odor stimuli. Significance Statement Mammalian amygdala development includes a growth period from childhood to adulthood, believed to support emotional and social learning. This amygdala growth is partly due to the maturation of neurons during adolescence in the paralaminar amygdala. However, the functional properties of these neurons are unknown. In our recent studies, we characterized the paralaminar amygdala in the mouse. Here, we investigate the properties of the adult PL in the mouse, revealing the existence of two neuronal subtypes that may play distinct functional roles in the adult brain. We further reveal the brain-wide input and output connectivity of the PL, indicating that the PL combines olfactory cues for emotional processing and delivers information to regions associated with reward and autonomic states.
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18
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Simoes de Souza F, Restrepo D. Olfactory cortex: Temporal segregation of inputs from the two nostrils. Curr Biol 2023; 33:R1286-R1288. [PMID: 38113838 DOI: 10.1016/j.cub.2023.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Piriform cortex processes odor information coming from two nostrils to give rise to unified perception of odorant identity and intensity. A new study reveals that human piriform cortex harbours distinct representations of odor input from ipsilateral and contralateral nostrils through temporal segregation.
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Affiliation(s)
- Fabio Simoes de Souza
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Diego Restrepo
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
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19
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Licht T, Yunerman M, Maor I, Lawabny N, Oz Rokach R, Shiff I, Mizrahi A, Rokni D. Adaptive olfactory circuitry restores function despite severe olfactory bulb degeneration. Curr Biol 2023; 33:4857-4868.e6. [PMID: 37858342 PMCID: PMC10681124 DOI: 10.1016/j.cub.2023.09.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 08/31/2023] [Accepted: 09/25/2023] [Indexed: 10/21/2023]
Abstract
The olfactory bulb (OB) is a critical component of mammalian olfactory neuroanatomy. Beyond being the first and sole relay station for olfactory information to the rest of the brain, it also contains elaborate stereotypical circuitry that is considered essential for olfaction. Indeed, substantial lesions of the OB in rodents lead to anosmia. Here, we examined the circuitry that underlies olfaction in a mouse model with severe developmental degeneration of the OB. These mice could perform odor-guided tasks and even responded normally to innate olfactory cues. Despite the near total loss of the OB, piriform cortices in these mice responded to odors, and its neural activity sufficed to decode odor identity. We found that sensory neurons express the full repertoire of olfactory receptors, and their axons project primarily to the rudiments of the OB but also, ectopically, to olfactory cortical regions. Within the OB, the number of principal neurons was greatly reduced, and the morphology of their dendrites was abnormal, extending over large regions within the OB. Glomerular organization was totally lost in the severe cases of OB degeneration and altered in the more conserved OBs. This study shows that olfactory functionality can be preserved despite reduced and aberrant circuitry that is missing many of the elements believed to be essential for olfaction, and it may explain reported retention of olfaction in humans with degenerated OBs.
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Affiliation(s)
- Tamar Licht
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel.
| | - Michael Yunerman
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel
| | - Ido Maor
- Department of Neurobiology, The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Naheel Lawabny
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel
| | - Renana Oz Rokach
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel
| | - Idit Shiff
- Genomics Applications Laboratory, Core Research Facility, Faculty of Medicine, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel
| | - Adi Mizrahi
- Department of Neurobiology, The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Dan Rokni
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel.
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20
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Sepahvand T, Nazari N, Qin T, Rajani V, Yuan Q. Olfactory threat extinction in the piriform cortex: An age-dependent employment of NMDA receptor-dependent long-term depression. Proc Natl Acad Sci U S A 2023; 120:e2309986120. [PMID: 37878718 PMCID: PMC10622944 DOI: 10.1073/pnas.2309986120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 09/27/2023] [Indexed: 10/27/2023] Open
Abstract
Extinction of threat memory is a measure of behavioral flexibility. In the absence of additional reinforcement, the extinction of learned behaviors allows animals and humans to adapt to their changing environment. Extinction mechanisms and their therapeutic implications for maladaptive learning have been extensively studied. However, how aging affects extinction learning is much less understood. Using a rat model of olfactory threat extinction, we show that the extinction of olfactory threat memory is impaired in aged Sprague-Darley rats. Following extinction training, long-term depression (LTD) in the piriform cortex (PC) was inducible ex vivo in aged rats and was NMDA receptor (NMDAR)-independent. On the other hand, adult rats acquired successful olfactory threat extinction, and LTD was not inducible following extinction training. Neuronal cFos activation in the posterior PC correlated with learning and extinction performance in rats. NMDAR blockade either systemically or locally in the PC during extinction training prevented successful extinction in adult rats, following which NMDAR-dependent LTD became inducible ex vivo. This suggests that extinction learning employs NMDAR-dependent LTD mechanisms in the PC of adult rats, thus occluding further LTD induction ex vivo. The rescue of olfactory threat extinction in aged rats by D-cycloserine, a partial NMDAR agonist, suggests that the impairment in olfactory threat extinction of aged animals may relate to NMDAR hypofunctioning and a lack of NMDAR-dependent LTD. These findings are consistent with an age-related switch from NMDAR-dependent to NMDAR-independent LTD in the PC. Optimizing NMDAR function in sensory cortices may improve learning and flexible behavior in the aged population.
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Affiliation(s)
- Tayebeh Sepahvand
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
| | - Negar Nazari
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
| | - Tian Qin
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
| | - Vishaal Rajani
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
| | - Qi Yuan
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
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21
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Cao Y, Cao S, Ge RL, Bao H, Mou Y, Ji W. Brain-aging related protein expression and imaging characteristics of mice exposed to chronic hypoxia at high altitude. Front Aging Neurosci 2023; 15:1268230. [PMID: 37849650 PMCID: PMC10577427 DOI: 10.3389/fnagi.2023.1268230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/18/2023] [Indexed: 10/19/2023] Open
Abstract
Objective To determine changes in protein expression related to brain aging and imaging features in mice after chronic hypoxia exposure at high altitude. Method A total of 24 healthy 4-week-old mice were randomly divided into high altitude hypoxia (HH) and plain control (PC) groups (n = 8 per group). HH mice were transported from Xi'an (450 m above sea level) to Maduo (4,300 m above sea level) while PC mice were raised in Xi'an. After 6 months, 7.0T magnetic resonance imaging (MRI) was performed. All mice completed T2-weighted imaging (T2WI), diffusion tensor imaging (DTI), resting-state functional MRI (rs-fMRI), arterial spin labeling (ASL), and magnetic resonance angiography (MRA) examinations. Next, brain slices were prepared and Nissl staining was used to observe morphological changes in neurons. Ultrastructural changes in neurons were observed by transmission electron microscopy. Expression changes of Caspase-3, klotho, P16, P21, and P53 at the gene and protein levels were detected by real-time PCR (RT-PCR) and Western blot. Results The number of neuronal Nissl bodies in the hippocampus and frontal cortex was significantly decreased in the HH group compared to the PC group. Some hippocampal and frontal cortical neurons were apoptotic, the nuclei were wrinkled, chromatin was aggregated, and most mitochondria were mildly swollen (crista lysis, fracture). Compared with the PC group, the HH group showed elevated expression of caspase-3 mRNA, P16 mRNA, P21 mRNA, and P53 mRNA in the hippocampus and frontal cortex. Expression of Klotho mRNA in the frontal cortex was also significantly decreased. Western blot results showed that caspase-3 protein expression in the hippocampus and frontal cortex of the HH group was increased compared with the PC group. Moreover, there was decreased Klotho protein expression and significantly increased P-P53 protein expression. Compared with the PC group, expression of P16 protein in the frontal cortex of the HH group was increased and the gray matter (GM) volume in the left visceral area, left caudate nucleus, and left piriform cortex was decreased. Furthermore, the amplitude of low frequency fluctuation was decreased in the left posterior nongranular insular lobe, right small cell reticular nucleus, left flocculus, left accessory flocculus, and left primary auditory area, but increased in the GM layer of the left superior colliculus. Regional homogeneity was decreased in the left and right olfactory regions, but increased in the left bed nucleus. After exposure to high altitude, functional connectivity (FC) between the bilateral caudate nucleus and thalamus, corpus callosum, cingulate gyrus, anterior limbic cortex, globus pallidus, and hippocampus was weakened. FC between the right caudate nucleus and hypothalamus and entorhinal cortex was also weakened. The fractional anisotropy value of the left hippocampus was decreased in the HH group. Compared with the PC group, the HH group showed significantly increased inner diameters of the bilateral common carotid artery and left internal carotid artery. The cerebral blood flow values of the bilateral cortex and bilateral hippocampus in the HH group did not change significantly. Conclusion Taken together, our findings show that chronic hypoxia exposure at high altitude may promote neuronal apoptosis and abnormal expression of related proteins, changing the structure and function of brain. These changes may contribute to brain aging.
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Affiliation(s)
- Yaxin Cao
- Tangdu Hospital of Air Force Military Medical University, Xi’an, China
| | - Shundao Cao
- Department of Neurology, Xi’an No. 1 Hospital, Xi’an, China
| | - Ri-Li Ge
- Research Center for High Altitude Medicine, Qinghai University, Xining, China
| | - Haihua Bao
- Department of Medical Imaging Center, Qinghai University Affiliated Hospital, Xining, China
| | - Yalin Mou
- Department of Medical Imaging Center, Qinghai University Affiliated Hospital, Xining, China
| | - Weizhong Ji
- Qinghai Provincial People’s Hospital, Xining, China
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22
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Srinivasan S, Daste S, Modi MN, Turner GC, Fleischmann A, Navlakha S. Effects of stochastic coding on olfactory discrimination in flies and mice. PLoS Biol 2023; 21:e3002206. [PMID: 37906721 PMCID: PMC10618007 DOI: 10.1371/journal.pbio.3002206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 08/21/2023] [Indexed: 11/02/2023] Open
Abstract
Sparse coding can improve discrimination of sensory stimuli by reducing overlap between their representations. Two factors, however, can offset sparse coding's benefits: similar sensory stimuli have significant overlap and responses vary across trials. To elucidate the effects of these 2 factors, we analyzed odor responses in the fly and mouse olfactory regions implicated in learning and discrimination-the mushroom body (MB) and the piriform cortex (PCx). We found that neuronal responses fall along a continuum from extremely reliable across trials to extremely variable or stochastic. Computationally, we show that the observed variability arises from noise within central circuits rather than sensory noise. We propose this coding scheme to be advantageous for coarse- and fine-odor discrimination. More reliable cells enable quick discrimination between dissimilar odors. For similar odors, however, these cells overlap and do not provide distinguishing information. By contrast, more unreliable cells are decorrelated for similar odors, providing distinguishing information, though these benefits only accrue with extended training with more trials. Overall, we have uncovered a conserved, stochastic coding scheme in vertebrates and invertebrates, and we identify a candidate mechanism, based on variability in a winner-take-all (WTA) inhibitory circuit, that improves discrimination with training.
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Affiliation(s)
- Shyam Srinivasan
- Kavli Institute for Brain and Mind, University of California, San Diego, California, United States of America
- Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Simon Daste
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, Rhode Island, United States of America
- Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island, United States of America
| | - Mehrab N. Modi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Glenn C. Turner
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Alexander Fleischmann
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, Rhode Island, United States of America
- Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island, United States of America
| | - Saket Navlakha
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
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23
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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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Sha MFR, Koga Y, Murata Y, Taniguchi M, Yamaguchi M. Learning-dependent structural plasticity of intracortical and sensory connections to functional domains of the olfactory tubercle. Front Neurosci 2023; 17:1247375. [PMID: 37680965 PMCID: PMC10480507 DOI: 10.3389/fnins.2023.1247375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 08/09/2023] [Indexed: 09/09/2023] Open
Abstract
The olfactory tubercle (OT), which is a component of the olfactory cortex and ventral striatum, has functional domains that play a role in odor-guided motivated behaviors. Learning odor-guided attractive and aversive behavior activates the anteromedial (am) and lateral (l) domains of the OT, respectively. However, the mechanism driving learning-dependent activation of specific OT domains remains unknown. We hypothesized that the neuronal connectivity of OT domains is plastically altered through olfactory experience. To examine the plastic potential of synaptic connections to OT domains, we optogenetically stimulated intracortical inputs from the piriform cortex or sensory inputs from the olfactory bulb to the OT in mice in association with a food reward for attractive learning and electrical foot shock for aversive learning. For both intracortical and sensory connections, axon boutons that terminated in the OT domains were larger in the amOT than in the lOT for mice exhibiting attractive learning and larger in the lOT than in the amOT for mice exhibiting aversive learning. These results indicate that both intracortical and sensory connections to the OT domains have learning-dependent plastic potential, suggesting that this plasticity underlies learning-dependent activation of specific OT domains and the acquisition of appropriate motivated behaviors.
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Affiliation(s)
| | | | | | | | - Masahiro Yamaguchi
- Department of Physiology, Kochi Medical School, Kochi University, Kochi, Japan
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25
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Todd LL, Sivakumar R, Lynch SG, Diebolt JH, White J, Villwock JA. Longitudinal Olfactory Patterns in Multiple Sclerosis: A Scoping Review and Implication for Use in Management of Disease. Int J MS Care 2023; 25:131-136. [PMID: 37250191 PMCID: PMC10211351 DOI: 10.7224/1537-2073.2022-019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND Although studies regarding multiple sclerosis (MS) and olfactory dysfunction (OD) have been previously described and summarized, there is not a sole review of longitudinal studies regarding the matter. This review examines the existing literature investigating MS and its effect on olfaction. In addition, the role of OD in the diagnosis and prognosis of MS is explored. METHODS A scoping review of the literature was performed covering longitudinal studies investigating MS and OD. Systematic searches of PubMed, Google Scholar, Web of Science, Embase, PsycInfo, Cumulative Index to Nursing and Allied Health Literature, AgeLine, and MEDLINE were performed using terms that encompassed MS and olfaction. The aim of this review was to build on the existing literature by summarizing only findings that were demonstrated longitudinally. RESULTS Of 6938 articles identified from the search, 9 met the inclusion criteria: longitudinal observation of relapsing-remitting or progressive MS. Olfaction was measured and scored using various testing arrays, and these scores were then correlated with a multitude of clinical markers. Across all studies, patients with MS demonstrated increased OD. Longitudinally, 2 contrasting patterns were identified: (1) clinical markers of acute inflammation correlated with an increased odor threshold and (2) clinical markers of neurodegeneration, or progression of disease, correlated with a decreased ability to discriminate and identify odors. CONCLUSIONS These studies suggest that olfaction is a dynamic, dependent variable of neurodegeneration, correlating with inflammation and clinical markers. This opens the door for future exploration of olfaction's relationship with MS diagnosis, characterization, and therapeutic response.
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Affiliation(s)
- Lauren L. Todd
- From the School of Medicine (LLT, RS), University of Kansas Medical Center, Kansas City, KS, USA
| | - Ram Sivakumar
- From the School of Medicine (LLT, RS), University of Kansas Medical Center, Kansas City, KS, USA
| | - Sharon G. Lynch
- From the Department of Neurology (SGL), University of Kansas Medical Center, Kansas City, KS, USA
| | - Jennifer H. Diebolt
- From the Department of Otolaryngology (JHD, JAV), University of Kansas Medical Center, Kansas City, KS, USA
| | - Jacob White
- Welch Medical Library, Johns Hopkins University, Baltimore, MD, USA (JW)
| | - Jennifer A. Villwock
- From the Department of Otolaryngology (JHD, JAV), University of Kansas Medical Center, Kansas City, KS, USA
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26
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Berners-Lee A, Shtrahman E, Grimaud J, Murthy VN. Experience-dependent evolution of odor mixture representations in piriform cortex. PLoS Biol 2023; 21:e3002086. [PMID: 37098044 PMCID: PMC10129003 DOI: 10.1371/journal.pbio.3002086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 03/17/2023] [Indexed: 04/26/2023] Open
Abstract
Rodents can learn from exposure to rewarding odors to make better and quicker decisions. The piriform cortex is thought to be important for learning complex odor associations; however, it is not understood exactly how it learns to remember discriminations between many, sometimes overlapping, odor mixtures. We investigated how odor mixtures are represented in the posterior piriform cortex (pPC) of mice while they learn to discriminate a unique target odor mixture against hundreds of nontarget mixtures. We find that a significant proportion of pPC neurons discriminate between the target and all other nontarget odor mixtures. Neurons that prefer the target odor mixture tend to respond with brief increases in firing rate at odor onset compared to other neurons, which exhibit sustained and/or decreased firing. We allowed mice to continue training after they had reached high levels of performance and find that pPC neurons become more selective for target odor mixtures as well as for randomly chosen repeated nontarget odor mixtures that mice did not have to discriminate from other nontargets. These single unit changes during overtraining are accompanied by better categorization decoding at the population level, even though behavioral metrics of mice such as reward rate and latency to respond do not change. However, when difficult ambiguous trial types are introduced, the robustness of the target selectivity is correlated with better performance on the difficult trials. Taken together, these data reveal pPC as a dynamic and robust system that can optimize for both current and possible future task demands at once.
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Affiliation(s)
- Alice Berners-Lee
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
| | - Elizabeth Shtrahman
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
| | - Julien Grimaud
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
- Cell Engineering Laboratory (CellTechs), Sup'Biotech, Villejuif, France
| | - Venkatesh N Murthy
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
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Organizational Principles of the Centrifugal Projections to the Olfactory Bulb. Int J Mol Sci 2023; 24:ijms24054579. [PMID: 36902010 PMCID: PMC10002860 DOI: 10.3390/ijms24054579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 03/03/2023] Open
Abstract
Centrifugal projections in the olfactory system are critical to both olfactory processing and behavior. The olfactory bulb (OB), the first relay station in odor processing, receives a substantial number of centrifugal inputs from the central brain regions. However, the anatomical organization of these centrifugal connections has not been fully elucidated, especially for the excitatory projection neurons of the OB, the mitral/tufted cells (M/TCs). Using rabies virus-mediated retrograde monosynaptic tracing in Thy1-Cre mice, we identified that the three most prominent inputs of the M/TCs came from the anterior olfactory nucleus (AON), the piriform cortex (PC), and the basal forebrain (BF), similar to the granule cells (GCs), the most abundant population of inhibitory interneurons in the OB. However, M/TCs received proportionally less input from the primary olfactory cortical areas, including the AON and PC, but more input from the BF and contralateral brain regions than GCs. Unlike organizationally distinct inputs from the primary olfactory cortical areas to these two types of OB neurons, inputs from the BF were organized similarly. Furthermore, individual BF cholinergic neurons innervated multiple layers of the OB, forming synapses on both M/TCs and GCs. Taken together, our results indicate that the centrifugal projections to different types of OB neurons may provide complementary and coordinated strategies in olfactory processing and behavior.
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28
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Prentice RN, Rizwan SB. Translational Considerations in the Development of Intranasal Treatments for Epilepsy. Pharmaceutics 2023; 15:pharmaceutics15010233. [PMID: 36678862 PMCID: PMC9865314 DOI: 10.3390/pharmaceutics15010233] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/09/2022] [Accepted: 11/29/2022] [Indexed: 01/13/2023] Open
Abstract
Epilepsy is a common and serious neurological disorder, to which a high proportion of patients continue to be considered "drug-resistant", despite the availability of a host of anti-seizure drugs. Investigation into new treatment strategies is therefore of great importance. One such strategy is the use of the nose to deliver drugs directly to the brain with the help of pharmaceutical formulation to overcome the physical challenges presented by this route. The following review explores intranasal delivery of anti-seizure drugs, covering the link between the nose and seizures, pathways from the nose to the brain, current formulations in clinical use, animal seizure models and their proposed application in studying intranasal treatments, and a critical discussion of relevant pre-clinical studies in the literature.
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29
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Zhou L, Ran Q, Yi R, Tang H, Zhang Y, Yu T. Glutamatergic Neurons of Piriform Cortex Delay Induction of Inhalational General Anesthesia. FUNDAMENTAL RESEARCH 2023. [DOI: 10.1016/j.fmre.2022.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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30
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Yan M, Xiong M, Wu Y, Lin D, Chen P, Chen J, Liu Z, Zhang H, Ren D, Fei E, Lai X, Zou S, Wang S. LRP4 is required for the olfactory association task in the piriform cortex. Cell Biosci 2022; 12:54. [PMID: 35526070 PMCID: PMC9080164 DOI: 10.1186/s13578-022-00792-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 04/18/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Low-density lipoprotein receptor-related protein 4 (LRP4) plays a critical role in the central nervous system (CNS), including hippocampal synaptic plasticity, maintenance of excitatory synaptic transmission, fear regulation, as well as long-term potentiation (LTP).
Results
In this study, we found that Lrp4 was highly expressed in layer II of the piriform cortex. Both body weight and brain weight decreased in Lrp4ECD/ECD mice without TMD (Transmembrane domain) and ICD (intracellular domain) of LRP4. However, in the piriform cortical neurons of Lrp4ECD/ECD mice, the spine density increased, and the frequency of both mEPSC (miniature excitatory postsynaptic current) and sEPSC (spontaneous excitatory postsynaptic current) was enhanced. Intriguingly, finding food in the buried food-seeking test was prolonged in both Lrp4ECD/ECD mice and Lrp4 cKO (conditional knockout of Lrp4 in the piriform cortex) mice.
Conclusions
This study indicated that the full length of LRP4 in the piriform cortex was necessary for maintaining synaptic plasticity and the integrity of olfactory function.
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Recruitment of interictal- and ictal-like discharges in posterior piriform cortex by delta-rate (1–4 Hz) focal bursts in anterior piriform cortex in vivo. Epilepsy Res 2022; 187:107032. [DOI: 10.1016/j.eplepsyres.2022.107032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/10/2022] [Accepted: 10/06/2022] [Indexed: 11/23/2022]
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32
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Chen Y, Chen X, Baserdem B, Zhan H, Li Y, Davis MB, Kebschull JM, Zador AM, Koulakov AA, Albeanu DF. High-throughput sequencing of single neuron projections reveals spatial organization in the olfactory cortex. Cell 2022; 185:4117-4134.e28. [PMID: 36306734 PMCID: PMC9681627 DOI: 10.1016/j.cell.2022.09.038] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 07/22/2022] [Accepted: 09/28/2022] [Indexed: 11/07/2022]
Abstract
In most sensory modalities, neuronal connectivity reflects behaviorally relevant stimulus features, such as spatial location, orientation, and sound frequency. By contrast, the prevailing view in the olfactory cortex, based on the reconstruction of dozens of neurons, is that connectivity is random. Here, we used high-throughput sequencing-based neuroanatomical techniques to analyze the projections of 5,309 mouse olfactory bulb and 30,433 piriform cortex output neurons at single-cell resolution. Surprisingly, statistical analysis of this much larger dataset revealed that the olfactory cortex connectivity is spatially structured. Single olfactory bulb neurons targeting a particular location along the anterior-posterior axis of piriform cortex also project to matched, functionally distinct, extra-piriform targets. Moreover, single neurons from the targeted piriform locus also project to the same matched extra-piriform targets, forming triadic circuit motifs. Thus, as in other sensory modalities, olfactory information is routed at early stages of processing to functionally diverse targets in a coordinated manner.
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Affiliation(s)
- Yushu Chen
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Xiaoyin Chen
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | | | - Huiqing Zhan
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Yan Li
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Martin B Davis
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | | | - Anthony M Zador
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
| | | | - Dinu F Albeanu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
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33
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Potts Y, Bekkers JM. Dopamine Increases the Intrinsic Excitability of Parvalbumin-Expressing Fast-Spiking Cells in the Piriform Cortex. Front Cell Neurosci 2022; 16:919092. [PMID: 35755774 PMCID: PMC9218566 DOI: 10.3389/fncel.2022.919092] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/20/2022] [Indexed: 11/13/2022] Open
Abstract
The piriform cortex (PCx) is essential for the adaptive processing of olfactory information. Neuromodulatory systems, including those utilizing serotonin, acetylcholine, noradrenaline, and dopamine, innervate and regulate neuronal activity in the PCx. Previous research has demonstrated the importance of acetylcholine, noradrenaline and serotonin in odor learning and memory. In contrast, the role of dopamine in the PCx remains under-explored. Here we examined how dopamine modulates the intrinsic electrical properties of identified classes of neurons in the PCx. We found that dopamine had no consistent effect on the intrinsic electrical properties of two types of glutamatergic neurons (semilunar and superficial pyramidal cells) or three types of GABAergic interneurons (horizontal, neurogliaform and somatastatin-expressing regular-spiking cells). However, dopamine had a striking effect on the intrinsic excitability of the parvalbumin-expressing fast-spiking (FS) class of GABAergic interneuron. Dopamine depolarized the resting potential, increased the input resistance and increased the firing frequency of FS cells. Co-application of dopamine with the D1-class dopamine receptor antagonist SCH 23390 blocked the effects of dopamine modulation on FS cells. Conversely, co-application of dopamine with the D2-class antagonist RS-(±)-sulpiride had no effect on dopamine modulation of these cells. Our results indicate that dopamine binds to D1-class dopamine receptors to increase the intrinsic excitability of FS cells. These findings suggest that dopamine has a highly targeted effect in the PCx and reveal how dopamine may modulate the balance between excitation and inhibition, with consequences for odor processing. In addition, our findings provide clues for understanding why neurodegenerative disorders that modify the dopamine system, such as Parkinson's disease, have a deleterious effect on the sense of smell, and may suggest novel diagnostics for the early detection of such disorders.
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Affiliation(s)
- Yasmin Potts
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - John M Bekkers
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
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Rajani V, Yuan Q. Noradrenergic Modulation of the Piriform Cortex: A Possible Avenue for Understanding Pre-Clinical Alzheimer’s Disease Pathogenesis. Front Cell Neurosci 2022; 16:908758. [PMID: 35722616 PMCID: PMC9204642 DOI: 10.3389/fncel.2022.908758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
Olfactory dysfunction is one of the biomarkers for Alzheimer’s disease (AD) diagnosis and progression. Deficits with odor identification and discrimination are common symptoms of pre-clinical AD, preceding severe memory disorder observed in advanced stages. As a result, understanding mechanisms of olfactory impairment is a major focus in both human studies and animal models of AD. Pretangle tau, a precursor to tau tangles, is first observed in the locus coeruleus (LC). In a recent animal model, LC pretangle tau leads to LC fiber degeneration in the piriform cortex (PC), a cortical area associated with olfactory dysfunction in both human AD and rodent models. Here, we review the role of LC-sourced NE in modulation of PC activity and suggest mechanisms by which pretangle tau-mediated LC dysfunction may impact olfactory processing in preclinical stage of AD. Understanding mechanisms of early olfactory impairment in AD may provide a critical window for detection and intervention of disease progression.
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35
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Olfactory Evaluation in Alzheimer’s Disease Model Mice. Brain Sci 2022; 12:brainsci12050607. [PMID: 35624994 PMCID: PMC9139301 DOI: 10.3390/brainsci12050607] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/26/2022] [Accepted: 05/03/2022] [Indexed: 11/17/2022] Open
Abstract
Olfactory dysfunction is considered a pre-cognitive biomarker of Alzheimer’s disease (AD). Because the olfactory system is highly conserved across species, mouse models corresponding to various AD etiologies have been bred and used in numerous studies on olfactory disorders. The olfactory behavior test is a method required for early olfactory dysfunction detection in AD model mice. Here, we review the olfactory evaluation of AD model mice, focusing on traditional olfactory detection methods, olfactory behavior involving the olfactory cortex, and the results of olfactory behavior in AD model mice, aiming to provide some inspiration for further development of olfactory detection methods in AD model mice.
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Matsukawa M, Yoshikawa M, Katsuyama N, Aizawa S, Sato T. The Anterior Piriform Cortex and Predator Odor Responses: Modulation by Inhibitory Circuits. Front Behav Neurosci 2022; 16:896525. [PMID: 35571276 PMCID: PMC9097892 DOI: 10.3389/fnbeh.2022.896525] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022] Open
Abstract
Rodents acquire more information from the sense of smell than humans because they have a nearly fourfold greater variety of olfactory receptors. They use olfactory information not only for obtaining food, but also for detecting environmental dangers. Predator-derived odor compounds provoke instinctive fear and stress reactions in animals. Inbred lines of experimental animals react in an innate stereotypical manner to predators even without prior exposure. Predator odors have also been used in models of various neuropsychiatric disorders, including post-traumatic stress disorder following a life-threatening event. Although several brain regions have been reported to be involved in predator odor-induced stress responses, in this mini review, we focus on the functional role of inhibitory neural circuits, especially in the anterior piriform cortex (APC). We also discuss the changes in these neural circuits following innate reactions to odor exposure. Furthermore, based on the three types of modulation of the stress response observed by our group using the synthetic fox odorant 2,5-dihydro-2,4,5-trimethylthiazoline, we describe how the APC interacts with other brain regions to regulate the stress response. Finally, we discuss the potential therapeutic application of odors in the treatment of stress-related disorders. A clearer understanding of the odor–stress response is needed to allow targeted modulation of the monoaminergic system and of the intracerebral inhibitory networks. It would be improved the quality of life of those who have stress-related conditions.
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Affiliation(s)
- Mutsumi Matsukawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Japan
- *Correspondence: Mutsumi Matsukawa,
| | - Masaaki Yoshikawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Japan
| | - Narumi Katsuyama
- Cognitive Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Japan
| | - Shin Aizawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Japan
| | - Takaaki Sato
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Ikeda, Japan
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Campos SM, Erley A, Ashraf Z, Wilczynski W. Signaler's Vasotocin Alters the Relationship between the Responder's Forebrain Catecholamines and Communication Behavior in Lizards (Anolis carolinensis). BRAIN, BEHAVIOR AND EVOLUTION 2022; 97:184-196. [PMID: 35320812 DOI: 10.1159/000524217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
Dynamic fluctuations in the distribution of catecholamines across the brain modulate the responsiveness of vertebrates to social stimuli. Previous work demonstrates that green anoles (Anolis carolinensis) increase chemosensory behavior in response to males treated with exogenous arginine vasotocin (AVT), but the neurochemical mechanisms underlying this behavioral shift remains unclear. Since central catecholamine systems, including dopamine, rapidly activate in response to social stimuli, we tested whether exogenous AVT in signalers (stimulus animals) impacts catecholamine concentrations in the forebrain (where olfactory and visual information are integrated and processed) of untreated lizard responders. We also tested whether AVT influences the relationship between forebrain catecholamine concentrations and communication behavior in untreated receivers. We measured global catecholamine (dopamine = DA, epinephrine = Epi, and norepinephrine = NE) concentrations in the forebrain of untreated responders using high-performance liquid chromatography-mass spectrometry following either a 30-min social interaction with a stimulus male or a period of social isolation. Stimulus males were injected with exogenous AVT or vehicle saline (SAL). We found that global DA, but not Epi or NE, concentrations were elevated in lizards responding to SAL-males relative to isolated lizards. Lizards interacting with AVT-males had DA, Epi and NE concentrations that were not significantly different from SAL or isolated groups. For behavior, we found a significant effect of social treatment (AVT vs. SAL) on the relationships between (1) DA concentrations and the motivation to perform a chemical display (latency to tongue flick) and (2) Epi concentrations and time spent displaying mostly green body coloration. We also found a significant negative correlation between DA concentrations and the latency to perform a visual display but found no effect of social treatment on this relationship. These data suggest that catecholamine concentrations in the forebrain of untreated responders are associated with chemical and visual communication in lizards and that signaler AVT alters this relationship for some, but not all, aspects of social communication.
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Affiliation(s)
- Stephanie M Campos
- Biology, Swarthmore College, Swarthmore, Pennsylvania, USA
- Neuroscience Institute and Center for Behavioral Neuroscience, Georgia State University, Atlanta, Georgia, USA
| | | | - Zoha Ashraf
- Biology, Swarthmore College, Swarthmore, Pennsylvania, USA
| | - Walter Wilczynski
- Neuroscience Institute and Center for Behavioral Neuroscience, Georgia State University, Atlanta, Georgia, USA
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38
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Chen Z, Padmanabhan K. Top-down feedback enables flexible coding strategies in the olfactory cortex. Cell Rep 2022; 38:110545. [PMID: 35320723 DOI: 10.1016/j.celrep.2022.110545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/30/2021] [Accepted: 03/01/2022] [Indexed: 11/03/2022] Open
Abstract
In chemical sensation, multiple models have been proposed to explain how odors are represented in the olfactory cortex. One hypothesis is that the combinatorial identity of active neurons within sniff-related time windows is critical, whereas another model proposes that it is the temporal structure of neural activity that is essential for encoding odor information. We find that top-down feedback to the main olfactory bulb dictates the information transmitted to the piriform cortex and switches between these coding strategies. Using a detailed network model, we demonstrate that feedback control of inhibition influences the excitation-inhibition balance in mitral cells, restructuring the dynamics of piriform cortical cells. This results in performance improvement in odor discrimination tasks. These findings present a framework for early olfactory computation, where top-down feedback to the bulb flexibly shapes the temporal structure of neural activity in the piriform cortex, allowing the early olfactory system to dynamically switch between two distinct coding models.
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Affiliation(s)
- Zhen Chen
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627, USA
| | - Krishnan Padmanabhan
- Department of Neuroscience, Neuroscience Graduate Program, Del Monte Institute for Neuroscience, Center for Visual Sciences, Intellectual and Developmental Disability Research Center, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
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Sánchez-González R, López-Mascaraque L. Lineage Relationships Between Subpallial Progenitors and Glial Cells in the Piriform Cortex. Front Neurosci 2022; 16:825969. [PMID: 35386594 PMCID: PMC8979001 DOI: 10.3389/fnins.2022.825969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/21/2022] [Indexed: 11/22/2022] Open
Abstract
The piriform cortex is a paleocortical area, located in the ventrolateral surface of the rodent forebrain, receiving direct input from the olfactory bulb. The three layers of the PC are defined by the diversity of glial and neuronal cells, marker expression, connections, and functions. However, the glial layering, ontogeny, and sibling cell relationship along the PC is an unresolved question in the field. Here, using multi-color genetic lineage tracing approaches with different StarTrack strategies, we performed a rigorous analysis of the derived cell progenies from progenitors located at the subpallium ventricular surface. First, we specifically targeted E12-progenitors with UbC-StarTrack to analyze their adult derived-cell progeny and their location within the piriform cortex layers. The vast majority of the cell progeny derived from targeted progenitors were identified as neurons, but also astrocytes and NG2 cells. Further, to specifically target single Gsx-2 subpallial progenitors and their derived cell-progeny in the piriform cortex, we used the UbC-(Gsx-2-hyPB)-StarTrack to perform an accurate analysis of their clonal relationships. Our results quantitatively delineate the adult clonal cell pattern from single subpallial E12-progenitors, focusing on glial cells. In summary, there is a temporal pattern in the assembly of the glial cell diversity in the piriform cortex, which also reveals spatio-temporal progenitor heterogeneity.
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Suzuki N, Tantirigama MLS, Aung KP, Huang HHY, Bekkers JM. Fast and slow feedforward inhibitory circuits for cortical odor processing. eLife 2022; 11:73406. [PMID: 35297763 PMCID: PMC8929928 DOI: 10.7554/elife.73406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 02/23/2022] [Indexed: 11/23/2022] Open
Abstract
Feedforward inhibitory circuits are key contributors to the complex interplay between excitation and inhibition in the brain. Little is known about the function of feedforward inhibition in the primary olfactory (piriform) cortex. Using in vivo two-photon-targeted patch clamping and calcium imaging in mice, we find that odors evoke strong excitation in two classes of interneurons – neurogliaform (NG) cells and horizontal (HZ) cells – that provide feedforward inhibition in layer 1 of the piriform cortex. NG cells fire much earlier than HZ cells following odor onset, a difference that can be attributed to the faster odor-driven excitatory synaptic drive that NG cells receive from the olfactory bulb. As a result, NG cells strongly but transiently inhibit odor-evoked excitation in layer 2 principal cells, whereas HZ cells provide more diffuse and prolonged feedforward inhibition. Our findings reveal unexpected complexity in the operation of inhibition in the piriform cortex.
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Affiliation(s)
- Norimitsu Suzuki
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Malinda L S Tantirigama
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, Australia.,Neurocure Center for Excellence, Charité Universitätsmedizin Berlin and Humboldt Universität, Berlin, Germany
| | - K Phyu Aung
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Helena H Y Huang
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - John M Bekkers
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, Australia
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Coureaud G, Thomas-Danguin T, Sandoz JC, Wilson DA. Biological constraints on configural odour mixture perception. J Exp Biol 2022; 225:274695. [PMID: 35285471 PMCID: PMC8996812 DOI: 10.1242/jeb.242274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Animals, including humans, detect odours and use this information to behave efficiently in the environment. Frequently, odours consist of complex mixtures of odorants rather than single odorants, and mixtures are often perceived as configural wholes, i.e. as odour objects (e.g. food, partners). The biological rules governing this 'configural perception' (as opposed to the elemental perception of mixtures through their components) remain weakly understood. Here, we first review examples of configural mixture processing in diverse species involving species-specific biological signals. Then, we present the original hypothesis that at least certain mixtures can be processed configurally across species. Indeed, experiments conducted in human adults, newborn rabbits and, more recently, in rodents and honeybees show that these species process some mixtures in a remarkably similar fashion. Strikingly, a mixture AB (A, ethyl isobutyrate; B, ethyl maltol) induces configural processing in humans, who perceive a mixture odour quality (pineapple) distinct from the component qualities (A, strawberry; B, caramel). The same mixture is weakly configurally processed in rabbit neonates, which perceive a particular odour for the mixture in addition to the component odours. Mice and honeybees also perceive the AB mixture configurally, as they respond differently to the mixture compared with its components. Based on these results and others, including neurophysiological approaches, we propose that certain mixtures are convergently perceived across various species of vertebrates/invertebrates, possibly as a result of a similar anatomical organization of their olfactory systems and the common necessity to simplify the environment's chemical complexity in order to display adaptive behaviours.
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Affiliation(s)
- Gérard Coureaud
- Centre de Recherche en Neurosciences de Lyon, Team Sensory Neuroethology (ENES), CNRS/INSERM/UCBL1/UJM, 69500 Lyon, France
| | - Thierry Thomas-Danguin
- Centre des Sciences du Goût et de l'Alimentation, Team Flavor, Food Oral Processing and Perception, INRAE, CNRS, Institut Agro Dijon, Université Bourgogne Franche-Comté, 21000 Dijon, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, CNRS, Université Paris-Saclay, IRD, 91190 Gif-sur-Yvette, France
| | - Donald A Wilson
- Department of Child & Adolescent Psychiatry, New York University Langone School of Medicine and Nathan S. Kline Institute for Psychiatric Research, New York, NY 10016, USA
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42
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Schizophrenia-like endurable behavioral and neuroadaptive changes induced by ketamine administration involve Angiotensin II AT 1 receptor. Behav Brain Res 2022; 425:113809. [PMID: 35218792 DOI: 10.1016/j.bbr.2022.113809] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 01/29/2022] [Accepted: 02/16/2022] [Indexed: 11/21/2022]
Abstract
Schizophrenia is a chronic disease affecting 1% worldwide population, of which 30% are refractory to the available treatments: thus, searching for new pharmacological targets is imperative. The acute and repeated ketamine administration are validated preclinical models that recreate the behavioral and neurochemical features of this pathology, including the parvalbumin-expressing interneurons dysfunction. Angiotensin II, through AT1 receptors (AT1-R), modulates the dopaminergic and GABAergic neurotransmission. We evaluated the AT1-R role in the long-term neuronal activation and behavioral alterations induced by repeated ketamine administration. Adult male Wistar rats received AT1-R antagonist candesartan/vehicle (days 1-10) and ketamine/saline (days 6-10). After 14 days of drug-free, neuronal activation and behavioral analysis were performed. Locomotor activity, social interaction and novel object recognition tests were assessed at basal conditions or after ketamine challenge. Immunostaining for c-Fos, GAD67 and parvalbumin were assessed after ketamine challenge in cingulate, insular, piriform, perirhinal, and entorhinal cortices, striatum, and hippocampus. Additionally, to evaluate the AT1-R involvement in acute ketamine psychotomimetic effects, the same behavioral tests were performed after 6 days of daily-candesartan and a single-ketamine administration. We found that ketamine-induced long-lasting schizophrenia-like behavioral alterations, and regional-dependent neuronal activation changes, involving the GABAergic neurotransmission system and the parvalbumin-expressing interneurons, were AT1-R-dependent. The AT1-R were not involved in the acute ketamine psychotomimetic effects. These results add new evidence to the wide spectrum of action of ketamine and strengthen the AT1-R involvement in endurable alterations induced by psychostimulants administration, previously proposed by our group, as well as their preponderant role in the development of psychiatric pathologies.
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Chee K, Razmara A, Geller AS, Harris WB, Restrepo D, Thompson JA, Kramer DR. The role of the piriform cortex in temporal lobe epilepsy: A current literature review. Front Neurol 2022; 13:1042887. [PMID: 36479052 PMCID: PMC9720270 DOI: 10.3389/fneur.2022.1042887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/07/2022] [Indexed: 11/22/2022] Open
Abstract
Temporal lobe epilepsy is the most common form of focal epilepsy and can have various detrimental consequences within many neurologic domains. Recent evidence suggests that the piriform cortex may also be implicated in seizure physiology. The piriform cortex is a primary component of the olfactory network and is located at the junction of the frontal and temporal lobes, wrapping around the entorhinal sulcus. Similar to the hippocampus, it is a tri-layered allocortical structure, with connections to many adjacent regions including the orbitofrontal cortex, amygdala, peri- and entorhinal cortices, and insula. Both animal and human studies have implicated the piriform cortex as a critical node in the temporal lobe epilepsy network. It has additionally been shown that resection of greater than half of the piriform cortex may significantly increase the odds of achieving seizure freedom. Laser interstitial thermal therapy has also been shown to be an effective treatment strategy with recent evidence hinting that ablation of the piriform cortex may be important for seizure control as well. We propose that sampling piriform cortex in intracranial stereoelectroencephalography (sEEG) procedures with the use of a temporal pole or amygdalar electrode would be beneficial for further understanding the role of the piriform cortex in temporal lobe epilepsy.
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Affiliation(s)
- Keanu Chee
- Department of Neurosurgery, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Ashkaun Razmara
- Department of Neurosurgery, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Aaron S Geller
- Department of Neurology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - William B Harris
- Department of Neurosurgery, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Diego Restrepo
- Department of Developmental and Cell Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - John A Thompson
- Department of Neurosurgery, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Daniel R Kramer
- Department of Neurosurgery, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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Nagappan S, Franks KM. Parallel processing by distinct classes of principal neurons in the olfactory cortex. eLife 2021; 10:73668. [PMID: 34913870 PMCID: PMC8676325 DOI: 10.7554/elife.73668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/19/2021] [Indexed: 01/02/2023] Open
Abstract
Understanding how distinct neuron types in a neural circuit process and propagate information is essential for understanding what the circuit does and how it does it. The olfactory (piriform, PCx) cortex contains two main types of principal neurons, semilunar (SL) and superficial pyramidal (PYR) cells. SLs and PYRs have distinct morphologies, local connectivity, biophysical properties, and downstream projection targets. Odor processing in PCx is thought to occur in two sequential stages. First, SLs receive and integrate olfactory bulb input and then PYRs receive, transform, and transmit SL input. To test this model, we recorded from populations of optogenetically identified SLs and PYRs in awake, head-fixed mice. Notably, silencing SLs did not alter PYR odor responses, and SLs and PYRs exhibited differences in odor tuning properties and response discriminability that were consistent with their distinct embeddings within a sensory-associative cortex. Our results therefore suggest that SLs and PYRs form parallel channels for differentially processing odor information in and through PCx.
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Affiliation(s)
| | - Kevin M Franks
- Department of Neurobiology, Duke University Medical School, Durham, United States
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Yan Y, Aierken A, Wang C, Song D, Ni J, Wang Z, Quan Z, Qing H. A potential biomarker of preclinical Alzheimer's disease: The olfactory dysfunction and its pathogenesis-based neural circuitry impairments. Neurosci Biobehav Rev 2021; 132:857-869. [PMID: 34810025 DOI: 10.1016/j.neubiorev.2021.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/26/2021] [Accepted: 11/07/2021] [Indexed: 01/24/2023]
Abstract
The olfactory dysfunction can signal and act as a potential biomarker of preclinical AD. However, the precise regulatory mechanism of olfactory function on the neural pathogenesis of AD is still unclear. The impairment of neural networks in olfaction system has been shown to be tightly associated with AD. As key brain regions of the olfactory system, the olfactory bulb (OB) and the piriform cortex (PCx) have a profound influence on the olfactory function. Therefore, this review will explore the mechanism of olfactory dysfunction in preclinical AD in the perspective of abnormal neural networks in the OB and PCx and their associated brain regions, especially from two aspects of aberrant oscillations and synaptic plasticity damages, which help better understand the underlying mechanism of olfactory neural network damages related to AD.
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Affiliation(s)
- Yan Yan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Ailikemu Aierken
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Chunjian Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Da Song
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Zhe Wang
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, The National Clinical Research Center for Geriatric Disease, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhenzhen Quan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
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Kumar A, Barkai E, Schiller J. Plasticity of olfactory bulb inputs mediated by dendritic NMDA-spikes in rodent piriform cortex. eLife 2021; 10:70383. [PMID: 34698637 PMCID: PMC8575458 DOI: 10.7554/elife.70383] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 10/25/2021] [Indexed: 11/19/2022] Open
Abstract
The piriform cortex (PCx) is essential for learning of odor information. The current view postulates that odor learning in the PCx is mainly due to plasticity in intracortical (IC) synapses, while odor information from the olfactory bulb carried via the lateral olfactory tract (LOT) is ‘hardwired.’ Here, we revisit this notion by studying location- and pathway-dependent plasticity rules. We find that in contrast to the prevailing view, synaptic and optogenetically activated LOT synapses undergo strong and robust long-term potentiation (LTP) mediated by only a few local NMDA-spikes delivered at theta frequency, while global spike timing-dependent plasticity (STDP) protocols failed to induce LTP in these distal synapses. In contrast, IC synapses in apical and basal dendrites undergo plasticity with both NMDA-spikes and STDP protocols but to a smaller extent compared with LOT synapses. These results are consistent with a self-potentiating mechanism of odor information via NMDA-spikes that can form branch-specific memory traces of odors that can further associate with contextual IC information via STDP mechanisms to provide cognitive and emotional value to odors.
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Affiliation(s)
- Amit Kumar
- Department of Physiology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Edi Barkai
- Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Jackie Schiller
- Department of Physiology, Technion-Israel Institute of Technology, Haifa, Israel
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Capsoni S, Fogli Iseppe A, Casciano F, Pignatelli A. Unraveling the Role of Dopaminergic and Calretinin Interneurons in the Olfactory Bulb. Front Neural Circuits 2021; 15:718221. [PMID: 34690707 PMCID: PMC8531203 DOI: 10.3389/fncir.2021.718221] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/31/2021] [Indexed: 11/27/2022] Open
Abstract
The perception and discriminating of odors are sensory activities that are an integral part of our daily life. The first brain region where odors are processed is the olfactory bulb (OB). Among the different cell populations that make up this brain area, interneurons play an essential role in this sensory activity. Moreover, probably because of their activity, they represent an exception compared to other parts of the brain, since OB interneurons are continuously generated in the postnatal and adult period. In this review, we will focus on periglomerular (PG) cells which are a class of interneurons found in the glomerular layer of the OB. These interneurons can be classified into distinct subtypes based on their neurochemical nature, based on the neurotransmitter and calcium-binding proteins expressed by these cells. Dopaminergic (DA) periglomerular cells and calretinin (CR) cells are among the newly generated interneurons and play an important role in the physiology of OB. In the OB, DA cells are involved in the processing of odors and the adaptation of the bulbar network to external conditions. The main role of DA cells in OB appears to be the inhibition of glutamate release from olfactory sensory fibers. Calretinin cells are probably the best morphologically characterized interneurons among PG cells in OB, but little is known about their function except for their inhibitory effect on noisy random excitatory signals arriving at the main neurons. In this review, we will mainly describe the electrophysiological properties related to the excitability profiles of DA and CR cells, with a particular view on the differences that characterize DA mature interneurons from cells in different stages of adult neurogenesis.
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Affiliation(s)
- Simona Capsoni
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
- Bio@SNS Laboratory of Biology, Scuola Normale Superiore, Pisa, Italy
| | - Alex Fogli Iseppe
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Fabio Casciano
- Department of Translational Medicine and LTTA Centre, University of Ferrara, Ferrara, Italy
- Interdepartmental Research Centre for the Study of Multiple Sclerosis and Inflammatory and Degenerative Diseases of the Nervous System, University of Ferrara, Ferrara, Italy
| | - Angela Pignatelli
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
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Tavoni G, Kersen DEC, Balasubramanian V. Cortical feedback and gating in odor discrimination and generalization. PLoS Comput Biol 2021; 17:e1009479. [PMID: 34634035 PMCID: PMC8530364 DOI: 10.1371/journal.pcbi.1009479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 10/21/2021] [Accepted: 09/24/2021] [Indexed: 11/30/2022] Open
Abstract
A central question in neuroscience is how context changes perception. In the olfactory system, for example, experiments show that task demands can drive divergence and convergence of cortical odor responses, likely underpinning olfactory discrimination and generalization. Here, we propose a simple statistical mechanism for this effect based on unstructured feedback from the central brain to the olfactory bulb, which represents the context associated with an odor, and sufficiently selective cortical gating of sensory inputs. Strikingly, the model predicts that both convergence and divergence of cortical odor patterns should increase when odors are initially more similar, an effect reported in recent experiments. The theory in turn predicts reversals of these trends following experimental manipulations and in neurological conditions that increase cortical excitability.
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Affiliation(s)
- Gaia Tavoni
- Computational Neuroscience Initiative, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Neuroscience, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - David E. Chen Kersen
- Computational Neuroscience Initiative, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Vijay Balasubramanian
- Computational Neuroscience Initiative, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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Olfactory Optogenetics: Light Illuminates the Chemical Sensing Mechanisms of Biological Olfactory Systems. BIOSENSORS-BASEL 2021; 11:bios11090309. [PMID: 34562900 PMCID: PMC8470751 DOI: 10.3390/bios11090309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/17/2021] [Accepted: 08/27/2021] [Indexed: 01/26/2023]
Abstract
The mammalian olfactory system has an amazing ability to distinguish thousands of odorant molecules at the trace level. Scientists have made great achievements on revealing the olfactory sensing mechanisms in decades; even though many issues need addressing. Optogenetics provides a novel technical approach to solve this dilemma by utilizing light to illuminate specific part of the olfactory system; which can be used in all corners of the olfactory system for revealing the olfactory mechanism. This article reviews the most recent advances in olfactory optogenetics devoted to elucidate the mechanisms of chemical sensing. It thus attempts to introduce olfactory optogenetics according to the structure of the olfactory system. It mainly includes the following aspects: the sensory input from the olfactory epithelium to the olfactory bulb; the influences of the olfactory bulb (OB) neuron activity patterns on olfactory perception; the regulation between the olfactory cortex and the olfactory bulb; and the neuromodulation participating in odor coding by dominating the olfactory bulb. Finally; current challenges and future development trends of olfactory optogenetics are proposed and discussed.
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50
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Abstract
Olfaction is fundamentally distinct from other sensory modalities. Natural odor stimuli are complex mixtures of volatile chemicals that interact in the nose with a receptor array that, in rodents, is built from more than 1,000 unique receptors. These interactions dictate a peripheral olfactory code, which in the brain is transformed and reformatted as it is broadcast across a set of highly interconnected olfactory regions. Here we discuss the problems of characterizing peripheral population codes for olfactory stimuli, of inferring the specific functions of different higher olfactory areas given their extensive recurrence, and of ultimately understanding how odor representations are linked to perception and action. We argue that, despite the differences between olfaction and other sensory modalities, addressing these specific questions will reveal general principles underlying brain function.
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Affiliation(s)
- David H Brann
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Sandeep Robert Datta
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA;
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