1
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Zhou Z, Yang X, Mao A, Xu H, Lin C, Yang M, Hu W, Shao J, Xu P, Li Y, Li W, Lin R, Zhang R, Xie Q, Xu Z, Meng W. Deficiency of CAMSAP2 impairs olfaction and the morphogenesis of mitral cells. EMBO Rep 2024; 25:2861-2877. [PMID: 38839944 PMCID: PMC11239855 DOI: 10.1038/s44319-024-00166-x] [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: 10/06/2023] [Revised: 04/07/2024] [Accepted: 04/22/2024] [Indexed: 06/07/2024] Open
Abstract
In developing olfactory bulb (OB), mitral cells (MCs) remodel their dendrites to establish the precise olfactory circuit, and these circuits are critical for individuals to sense odors and elicit behaviors for survival. However, how microtubules (MTs) participate in the process of dendritic remodeling remains elusive. Here, we reveal that calmodulin-regulated spectrin-associated proteins (CAMSAPs), a family of proteins that bind to the minus-end of the noncentrosomal MTs, play a crucial part in the development of MC dendrites. We observed that Camsap2 knockout (KO) males are infertile while the reproductive tract is normal. Further study showed that the infertility was due to the severe defects of mating behavior in male mice. Besides, mice with loss-of-function displayed defects in the sense of smell. Furthermore, we found that the deficiency of CAMSAP2 impairs the classical morphology of MCs, and the CAMSAP2-dependent dendritic remodeling process is responsible for this defect. Thus, our findings demonstrate that CAMSAP2 plays a vital role in regulating the development of MCs.
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Affiliation(s)
- Zhengrong Zhou
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China.
- Neuroscience Center, Department of Basic Medical Sciences, Shantou University Medical College, 515041, Shantou, Guangdong, China.
| | - Xiaojuan Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Aihua Mao
- Biology Department, College of Sciences, Shantou University, 515063, Shantou, China
| | - Honglin Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Chunnuan Lin
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Mengge Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Weichang Hu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Jinhui Shao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Peipei Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yuejia Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Wenguang Li
- Animal Laboratory Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Ruifan Lin
- Chinese Academy of Chinese Medical Sciences, 100700, Beijing, China
| | - Rui Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Qi Xie
- Chinese Academy of Chinese Medical Sciences, 100700, Beijing, China
| | - Zhiheng Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
- Innovation Academy for Seed Design, Chinese Academy of Sciences, 100101, Beijing, China
| | - Wenxiang Meng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
- Innovation Academy for Seed Design, Chinese Academy of Sciences, 100101, Beijing, China.
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2
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Peace ST, Johnson BC, Werth JC, Li G, Kaiser ME, Fukunaga I, Schaefer AT, Molnar AC, Cleland TA. Coherent olfactory bulb gamma oscillations arise from coupling independent columnar oscillators. J Neurophysiol 2024; 131:492-508. [PMID: 38264784 PMCID: PMC7615692 DOI: 10.1152/jn.00361.2023] [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: 09/29/2023] [Revised: 01/19/2024] [Accepted: 01/20/2024] [Indexed: 01/25/2024] Open
Abstract
Spike timing-based representations of sensory information depend on embedded dynamical frameworks within neuronal networks that establish the rules of local computation and interareal communication. Here, we investigated the dynamical properties of olfactory bulb circuitry in mice of both sexes using microelectrode array recordings from slice and in vivo preparations. Neurochemical activation or optogenetic stimulation of sensory afferents evoked persistent gamma oscillations in the local field potential. These oscillations arose from slower, GABA(A) receptor-independent intracolumnar oscillators coupled by GABA(A)-ergic synapses into a faster, broadly coherent network oscillation. Consistent with the theoretical properties of coupled-oscillator networks, the spatial extent of zero-phase coherence was bounded in slices by the reduced density of lateral interactions. The intact in vivo network, however, exhibited long-range lateral interactions that suffice in simulation to enable zero-phase gamma coherence across the olfactory bulb. The timing of action potentials in a subset of principal neurons was phase-constrained with respect to evoked gamma oscillations. Coupled-oscillator dynamics in olfactory bulb thereby enable a common clock, robust to biological heterogeneities, that is capable of supporting gamma-band spike synchronization and phase coding across the ensemble of activated principal neurons.NEW & NOTEWORTHY Odor stimulation evokes rhythmic gamma oscillations in the field potential of the olfactory bulb, but the dynamical mechanisms governing these oscillations have remained unclear. Establishing these mechanisms is important as they determine the biophysical capacities of the bulbar circuit to, for example, maintain zero-phase coherence across a spatially extended network, or coordinate the timing of action potentials in principal neurons. These properties in turn constrain and suggest hypotheses of sensory coding.
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Affiliation(s)
- Shane T Peace
- Department of Neurobiology & Behavior, Cornell University, Ithaca, New York, United States
| | - Benjamin C Johnson
- Department of Electrical and Computer Engineering, Cornell University, Ithaca, New York, United States
| | - Jesse C Werth
- Department of Psychology, Cornell University, Ithaca, New York, United States
| | - Guoshi Li
- Department of Psychology, Cornell University, Ithaca, New York, United States
| | - Martin E Kaiser
- Behavioural Neurophysiology, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Izumi Fukunaga
- Behavioural Neurophysiology, Max Planck Institute for Medical Research, Heidelberg, Germany
- Neurophysiology of Behaviour Laboratory, The Francis Crick Institute, London, United Kingdom
- Sensory and Behavioural Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Andreas T Schaefer
- Behavioural Neurophysiology, Max Planck Institute for Medical Research, Heidelberg, Germany
- Neurophysiology of Behaviour Laboratory, The Francis Crick Institute, London, United Kingdom
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
| | - Alyosha C Molnar
- Department of Electrical and Computer Engineering, Cornell University, Ithaca, New York, United States
| | - Thomas A Cleland
- Department of Psychology, Cornell University, Ithaca, New York, United States
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3
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Cohen O, Kahan A, Steinberg I, Malinowski ST, Rokni D, Spehr M, Ben-Shaul Y. Stimulus-Induced Theta-Band LFP Oscillations Format Neuronal Representations of Social Chemosignals in the Mouse Accessory Olfactory Bulb. J Neurosci 2023; 43:8700-8722. [PMID: 37903594 PMCID: PMC10727196 DOI: 10.1523/jneurosci.1055-23.2023] [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: 06/07/2023] [Revised: 10/13/2023] [Accepted: 10/16/2023] [Indexed: 11/01/2023] Open
Abstract
Social communication is crucial for the survival of many species. In most vertebrates, a dedicated chemosensory system, the vomeronasal system (VNS), evolved to process ethologically relevant chemosensory cues. The first central processing stage of the VNS is the accessory olfactory bulb (AOB), which sends information to downstream brain regions via AOB mitral cells (AMCs). Recent studies provided important insights about the functional properties of AMCs, but little is known about the principles that govern their coordinated activity. Here, we recorded local field potentials (LFPs) and single-unit activity in the AOB of adult male and female mice during presentation of natural stimuli. Our recordings reveal prominent LFP theta-band oscillatory episodes with a characteristic spatial pattern across the AOB. Throughout an experiment, the AOB network shows varying degrees of similarity to this pattern, in a manner that depends on the sensory stimulus. Analysis of LFP signal polarity and single-unit activity indicates that oscillatory episodes are generated locally within the AOB, likely representing a reciprocal interaction between AMCs and granule cells. Notably, spike times of many AMCs are constrained to the negative LFP oscillation phase in a manner that can drastically affect integration by downstream processing stages. Based on these observations, we propose that LFP oscillations may gate, bind, and organize outgoing signals from individual AOB neurons to downstream processing stages. Our findings suggest that, as in other neuronal systems and brain regions, population-level oscillations play a key role in organizing and enhancing transmission of socially relevant chemosensory information.SIGNIFICANCE STATEMENT The accessory olfactory bulb (AOB) is the first central stage of the vomeronasal system, a chemosensory system dedicated to processing cues from other organisms. Information from the AOB is conveyed to other brain regions via activity of its principal neurons, AOB mitral cells (AMCs). Here, we show that socially relevant sensory stimulation of the mouse vomeronasal system leads not only to changes in AMC activity, but also to distinct theta-band (∼5 Hz) oscillatory episodes in the local field potential. Notably AMCs favor the negative phase of these oscillatory events. Our findings suggest a novel mechanism for the temporal coordination of distributed patterns of neuronal activity, which can serve to efficiently activate downstream processing stages.
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Affiliation(s)
- Oksana Cohen
- Department of Medical Neurobiology, Institute for Medical Research Israel Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Anat Kahan
- Department of Medical Neurobiology, Institute for Medical Research Israel Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
- Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot 7610001, Israel
| | - Idan Steinberg
- Alpha Program, Future Scientist Center, The Hebrew University Youth Division, Jerusalem 9190401, Israel
| | - Sebastian T Malinowski
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, 52062 Aachen, Germany
| | - Dan Rokni
- Department of Medical Neurobiology, Institute for Medical Research Israel Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Marc Spehr
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, 52062 Aachen, Germany
| | - Yoram Ben-Shaul
- Department of Medical Neurobiology, Institute for Medical Research Israel Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
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4
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Danskin BP, Hattori R, Zhang YE, Babic Z, Aoi M, Komiyama T. Exponential history integration with diverse temporal scales in retrosplenial cortex supports hyperbolic behavior. SCIENCE ADVANCES 2023; 9:eadj4897. [PMID: 38019904 PMCID: PMC10686558 DOI: 10.1126/sciadv.adj4897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023]
Abstract
Animals use past experience to guide future choices. The integration of experiences typically follows a hyperbolic, rather than exponential, decay pattern with a heavy tail for distant history. Hyperbolic integration affords sensitivity to both recent environmental dynamics and long-term trends. However, it is unknown how the brain implements hyperbolic integration. We found that mouse behavior in a foraging task showed hyperbolic decay of past experience, but the activity of cortical neurons showed exponential decay. We resolved this apparent mismatch by observing that cortical neurons encode history information with heterogeneous exponential time constants that vary across neurons. A model combining these diverse timescales recreated the heavy-tailed, hyperbolic history integration observed in behavior. In particular, the time constants of retrosplenial cortex (RSC) neurons best matched the behavior, and optogenetic inactivation of RSC uniquely reduced behavioral history dependence. These results indicate that behavior-relevant history information is maintained across multiple timescales in parallel and that RSC is a critical reservoir of information guiding decision-making.
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Affiliation(s)
- Bethanny P. Danskin
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA, USA
| | - Ryoma Hattori
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA, USA
| | - Yu E. Zhang
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA, USA
| | - Zeljana Babic
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA, USA
| | - Mikio Aoi
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA, USA
| | - Takaki Komiyama
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA, USA
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5
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Diaz C, Franks KM, Blazing RM. Neuroscience: Seq-ing maps in the olfactory cortex. Curr Biol 2023; 33:R266-R269. [PMID: 37040708 PMCID: PMC10644302 DOI: 10.1016/j.cub.2023.02.055] [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] [Indexed: 04/13/2023]
Abstract
Many cortical brain regions are spatially organized to optimize sensory representation. Such topographic maps have so far been elusive in the olfactory cortex. A high-throughput tracing study reveals that the neural circuits connecting olfactory regions are indeed topographically organized.
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Affiliation(s)
- Carolyn Diaz
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | - Kevin M Franks
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA.
| | - Robin M Blazing
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
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6
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Ananthamurthy KG, Bhalla US. Synthetic Data Resource and Benchmarks for Time Cell Analysis and Detection Algorithms. eNeuro 2023; 10:ENEURO.0007-22.2023. [PMID: 36823166 PMCID: PMC10027052 DOI: 10.1523/eneuro.0007-22.2023] [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: 01/02/2022] [Revised: 11/21/2022] [Accepted: 02/09/2023] [Indexed: 02/25/2023] Open
Abstract
Hippocampal CA1 cells take part in reliable, time-locked activity sequences in tasks that involve an association between temporally separated stimuli, in a manner that tiles the interval between the stimuli. Such cells have been termed time cells. Here, we adopt a first-principles approach to comparing diverse analysis and detection algorithms for identifying time cells. We generated synthetic activity datasets using calcium signals recorded in vivo from the mouse hippocampus using two-photon (2-P) imaging, as template response waveforms. We assigned known, ground truth values to perturbations applied to perfect activity signals, including noise, calcium event width, timing imprecision, hit trial ratio and background (untuned) activity. We tested a range of published and new algorithms and their variants on this dataset. We find that most algorithms correctly classify over 80% of cells, but have different balances between true and false positives, and different sensitivity to the five categories of perturbation. Reassuringly, most methods are reasonably robust to perturbations, including background activity, and show good concordance in classification of time cells. The same algorithms were also used to analyze and identify time cells in experimental physiology datasets recorded in vivo and most show good concordance.
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Affiliation(s)
- Kambadur G Ananthamurthy
- National Centre for Biological Sciences - Tata Institute of Fundamental Research, Bellary Road, Bengaluru - 560065, Karnataka, India
| | - Upinder S Bhalla
- National Centre for Biological Sciences - Tata Institute of Fundamental Research, Bellary Road, Bengaluru - 560065, Karnataka, India
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7
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Robust odor identification in novel olfactory environments in mice. Nat Commun 2023; 14:673. [PMID: 36781878 PMCID: PMC9925783 DOI: 10.1038/s41467-023-36346-x] [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: 09/15/2020] [Accepted: 01/26/2023] [Indexed: 02/15/2023] Open
Abstract
Relevant odors signaling food, mates, or predators can be masked by unpredictable mixtures of less relevant background odors. Here, we developed a mouse behavioral paradigm to test the role played by the novelty of the background odors. During the task, mice identified target odors in previously learned background odors and were challenged by catch trials with novel background odors, a task similar to visual CAPTCHA. Female wild-type (WT) mice could accurately identify known targets in novel background odors. WT mice performance was higher than linear classifiers and the nearest neighbor classifier trained using olfactory bulb glomerular activation patterns. Performance was more consistent with an odor deconvolution method. We also used our task to investigate the performance of female Cntnap2-/- mice, which show some autism-like behaviors. Cntnap2-/- mice had glomerular activation patterns similar to WT mice and matched WT mice target detection for known background odors. However, Cntnap2-/- mice performance fell almost to chance levels in the presence of novel backgrounds. Our findings suggest that mice use a robust algorithm for detecting odors in novel environments and this computation is impaired in Cntnap2-/- mice.
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8
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Hook C, Puche AC. Bulbar projecting subcortical GABAergic neurons send collateral branches extensively and selectively to primary olfactory cortical regions. J Comp Neurol 2023; 531:451-460. [PMID: 36463397 PMCID: PMC9795336 DOI: 10.1002/cne.25434] [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: 07/06/2022] [Revised: 09/26/2022] [Accepted: 10/27/2022] [Indexed: 12/05/2022]
Abstract
Circuit operations of the olfactory bulb are modulated by higher order projections from multiple regions, many of which are themselves targets of bulbar output. Multiple glutamatergic regions project to the olfactory bulb, including the anterior olfactory nucleus (AON), prefrontal cortex (PFC), piriform cortex (PC), entorhinal cortex (EC), and tenia tecta (TT). In contrast, only one region provides GABAergic projections to the bulb. These GABA neurons are located in the horizontal limb of the diagonal band of Broca extending posteriorly through the magnocellular preoptic nucleus to the nucleus of the lateral olfactory bulb. However, it was unclear whether bulbar projecting GABAergic neurons collaterallize projecting to other brain regions. To address this, we mapped collateral projections from bulbar projecting GABAergic neurons using intersectional strategies of viral and traditional tract tracers. This approach revealed bulbar projecting GABAergic neurons show remarkable specificity targeting other primary olfactory cortical regions exhibiting abundant collateral projections into the accessory olfactory bulb, AON, PFC, PC, and TT. The only "nonolfactory" region receiving collateral projections was sparse connectivity to the medial prefrontal orbital cortex. This suggests that basal forebrain inhibitory feedback also modulates glutamatergic feedback areas that are themselves prominent bulbar projection regions. Thus, inhibitory feedback may be simultaneously modulating both synaptic processing of olfactory information in the bulb and associational processing of olfactory information from primary olfactory cortex. We hypothesize that these olfactory GABAergic feedback neurons are a regulator of the entire olfactory system.
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Affiliation(s)
- Chelsea Hook
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Adam C Puche
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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9
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Chae H, Banerjee A, Dussauze M, Albeanu DF. Long-range functional loops in the mouse olfactory system and their roles in computing odor identity. Neuron 2022; 110:3970-3985.e7. [PMID: 36174573 PMCID: PMC9742324 DOI: 10.1016/j.neuron.2022.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 07/12/2022] [Accepted: 09/02/2022] [Indexed: 12/15/2022]
Abstract
Elucidating the neural circuits supporting odor identification remains an open challenge. Here, we analyze the contribution of the two output cell types of the mouse olfactory bulb (mitral and tufted cells) to decode odor identity and concentration and its dependence on top-down feedback from their respective major cortical targets: piriform cortex versus anterior olfactory nucleus. We find that tufted cells substantially outperform mitral cells in decoding both odor identity and intensity. Cortical feedback selectively regulates the activity of its dominant bulb projection cell type and implements different computations. Piriform feedback specifically restructures mitral responses, whereas feedback from the anterior olfactory nucleus preferentially controls the gain of tufted representations without altering their odor tuning. Our results identify distinct functional loops involving the mitral and tufted cells and their cortical targets. We suggest that in addition to the canonical mitral-to-piriform pathway, tufted cells and their target regions are ideally positioned to compute odor identity.
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Affiliation(s)
- Honggoo Chae
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Arkarup Banerjee
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA; Cold Spring Harbor Laboratory School for Biological Sciences, Cold Spring Harbor, NY, USA
| | - Marie Dussauze
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA; Cold Spring Harbor Laboratory School for Biological Sciences, Cold Spring Harbor, NY, USA
| | - Dinu F Albeanu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA; Cold Spring Harbor Laboratory School for Biological Sciences, Cold Spring Harbor, NY, USA.
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10
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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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11
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Zanon M, Zanini D, Haase A. All-optical manipulation of the Drosophila olfactory system. Sci Rep 2022; 12:8506. [PMID: 35595846 PMCID: PMC9123005 DOI: 10.1038/s41598-022-12237-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/09/2022] [Indexed: 11/09/2022] Open
Abstract
Thanks to its well-known neuroanatomy, limited brain size, complex behaviour, and the extensive genetic methods, Drosophila has become an indispensable model in neuroscience. A vast number of studies have focused on its olfactory system and the processing of odour information. Optogenetics is one of the recently developed genetic tools that significantly advance this field of research, allowing to replace odour stimuli by direct neuronal activation with light. This becomes a universal all-optical toolkit when spatially selective optogenetic activation is combined with calcium imaging to read out neuronal responses. Initial experiments showed a successful implementation to study the olfactory system in fish and mice, but the olfactory system of Drosophila has been so far precluded from an application. To fill this gap, we present here optogenetic tools to selectively stimulate functional units in the Drosophila olfactory system, combined with two-photon calcium imaging to read out the activity patterns elicited by these stimuli at different levels of the brain. This method allows to study the spatial and temporal features of the information flow and reveals the functional connectivity in the olfactory network.
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Affiliation(s)
- Mirko Zanon
- Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy.
- Department of Physics, University of Trento, Trento, Italy.
| | - Damiano Zanini
- Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy
- Neurobiology and Genetics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Albrecht Haase
- Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy.
- Department of Physics, University of Trento, Trento, Italy.
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12
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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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13
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Bast WG, Albeanu DF. Mapping odorant receptors to their glomeruli. Nat Neurosci 2022; 25:405-407. [DOI: 10.1038/s41593-022-01045-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Hiratani N, Latham PE. Developmental and evolutionary constraints on olfactory circuit selection. Proc Natl Acad Sci U S A 2022; 119:e2100600119. [PMID: 35263217 PMCID: PMC8931209 DOI: 10.1073/pnas.2100600119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 01/14/2022] [Indexed: 11/18/2022] Open
Abstract
SignificanceIn this work, we explore the hypothesis that biological neural networks optimize their architecture, through evolution, for learning. We study early olfactory circuits of mammals and insects, which have relatively similar structure but a huge diversity in size. We approximate these circuits as three-layer networks and estimate, analytically, the scaling of the optimal hidden-layer size with input-layer size. We find that both longevity and information in the genome constrain the hidden-layer size, so a range of allometric scalings is possible. However, the experimentally observed allometric scalings in mammals and insects are consistent with biologically plausible values. This analysis should pave the way for a deeper understanding of both biological and artificial networks.
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Affiliation(s)
- Naoki Hiratani
- Gatsby Computational Neuroscience Unit, University College London, London W1T 4JG, United Kingdom
| | - Peter E. Latham
- Gatsby Computational Neuroscience Unit, University College London, London W1T 4JG, United Kingdom
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15
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Xue Y, Waller L, Adesnik H, Pégard N. Three-dimensional multi-site random access photostimulation (3D-MAP). eLife 2022; 11:73266. [PMID: 35156923 PMCID: PMC8843094 DOI: 10.7554/elife.73266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 01/19/2022] [Indexed: 11/22/2022] Open
Abstract
Optical control of neural ensemble activity is crucial for understanding brain function and disease, yet no technology can achieve optogenetic control of very large numbers of neurons at an extremely fast rate over a large volume. State-of-the-art multiphoton holographic optogenetics requires high-power illumination that only addresses relatively small populations of neurons in parallel. Conversely, one-photon holographic techniques can stimulate more neurons with two to three orders lower power, but with limited resolution or addressable volume. Perhaps most problematically, two-photon holographic optogenetic systems are extremely expensive and sophisticated which has precluded their broader adoption in the neuroscience community. To address this technical gap, we introduce a new one-photon light sculpting technique, three-dimensional multi-site random access photostimulation (3D-MAP), that overcomes these limitations by modulating light dynamically, both in the spatial and in the angular domain at multi-kHz rates. We use 3D-MAP to interrogate neural circuits in 3D and demonstrate simultaneous photostimulation and imaging of dozens of user-selected neurons in the intact mouse brain in vivo with high spatio-temporal resolution. 3D-MAP can be broadly adopted for high-throughput all-optical interrogation of brain circuits owing to its powerful combination of scale, speed, simplicity, and cost.
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Affiliation(s)
- Yi Xue
- Department of Electrical Engineering & Computer Sciences, University of California, Berkeley
| | - Laura Waller
- Department of Electrical Engineering & Computer Sciences, University of California, Berkeley
| | - Hillel Adesnik
- Department of Molecular & Cell Biology, University of California, Berkeley
- Helen Wills Neuroscience Institute, University of California, Berkeley
| | - Nicolas Pégard
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill
- UNC Neuroscience Center, University of North Carolina at Chapel Hill
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16
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Kersen DEC, Tavoni G, Balasubramanian V. Connectivity and dynamics in the olfactory bulb. PLoS Comput Biol 2022; 18:e1009856. [PMID: 35130267 PMCID: PMC8853646 DOI: 10.1371/journal.pcbi.1009856] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 02/17/2022] [Accepted: 01/22/2022] [Indexed: 12/22/2022] Open
Abstract
Dendrodendritic interactions between excitatory mitral cells and inhibitory granule cells in the olfactory bulb create a dense interaction network, reorganizing sensory representations of odors and, consequently, perception. Large-scale computational models are needed for revealing how the collective behavior of this network emerges from its global architecture. We propose an approach where we summarize anatomical information through dendritic geometry and density distributions which we use to calculate the connection probability between mitral and granule cells, while capturing activity patterns of each cell type in the neural dynamical systems theory of Izhikevich. In this way, we generate an efficient, anatomically and physiologically realistic large-scale model of the olfactory bulb network. Our model reproduces known connectivity between sister vs. non-sister mitral cells; measured patterns of lateral inhibition; and theta, beta, and gamma oscillations. The model in turn predicts testable relationships between network structure and several functional properties, including lateral inhibition, odor pattern decorrelation, and LFP oscillation frequency. We use the model to explore the influence of cortex on the olfactory bulb, demonstrating possible mechanisms by which cortical feedback to mitral cells or granule cells can influence bulbar activity, as well as how neurogenesis can improve bulbar decorrelation without requiring cell death. Our methodology provides a tractable tool for other researchers.
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Affiliation(s)
- 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
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - 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
| | - Vijay Balasubramanian
- Computational Neuroscience Initiative, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Bioengineering, 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, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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17
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Yang W, Wu T, Tu S, Qin Y, Shen C, Li J, Choi MK, Duan F, Zhang Y. Redundant neural circuits regulate olfactory integration. PLoS Genet 2022; 18:e1010029. [PMID: 35100258 PMCID: PMC8830790 DOI: 10.1371/journal.pgen.1010029] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 02/10/2022] [Accepted: 01/11/2022] [Indexed: 11/18/2022] Open
Abstract
Olfactory integration is important for survival in a natural habitat. However, how the nervous system processes signals of two odorants present simultaneously to generate a coherent behavioral response is poorly understood. Here, we characterize circuit basis for a form of olfactory integration in Caenorhabditis elegans. We find that the presence of a repulsive odorant, 2-nonanone, that signals threat strongly blocks the attraction of other odorants, such as isoamyl alcohol (IAA) or benzaldehyde, that signal food. Using a forward genetic screen, we found that genes known to regulate the structure and function of sensory neurons, osm-5 and osm-1, played a critical role in the integration process. Loss of these genes mildly reduces the response to the repellent 2-nonanone and disrupts the integration effect. Restoring the function of OSM-5 in either AWB or ASH, two sensory neurons known to mediate 2-nonanone-evoked avoidance, is sufficient to rescue. Sensory neurons AWB and downstream interneurons AVA, AIB, RIM that play critical roles in olfactory sensorimotor response are able to process signals generated by 2-nonanone or IAA or the mixture of the two odorants and contribute to the integration. Thus, our results identify redundant neural circuits that regulate the robust effect of a repulsive odorant to block responses to attractive odorants and uncover the neuronal and cellular basis for this complex olfactory task. In their natural environment, animals, including humans, encounter complex olfactory stimuli. Thus, how the brain processes multiple sensory cues to generate a coherent behavioral output is critical for the survival of the animal. In the present study, we combined molecular cellular genetics, optical physiology and behavioral analysis to study a common olfactory phenomenon in which the presence of one odorant blocks the response to another. Our results show that the integrated response is regulated by redundant neuronal circuits that engage several interneurons essential for olfactory sensorimotor responses, a mechanism that likely ensures a robust behavioral response to sensory cues representing information critical for survival.
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Affiliation(s)
- Wenxing Yang
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
- * E-mail: (WY); (YZ)
| | - Taihong Wu
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
| | - Shasha Tu
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Yuang Qin
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Chengchen Shen
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Jiangyun Li
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Myung-Kyu Choi
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
| | - Fengyun Duan
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail: (WY); (YZ)
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18
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Sridharan S, Gajowa MA, Ogando MB, Jagadisan UK, Abdeladim L, Sadahiro M, Bounds HA, Hendricks WD, Turney TS, Tayler I, Gopakumar K, Oldenburg IA, Brohawn SG, Adesnik H. High-performance microbial opsins for spatially and temporally precise perturbations of large neuronal networks. Neuron 2022; 110:1139-1155.e6. [PMID: 35120626 PMCID: PMC8989680 DOI: 10.1016/j.neuron.2022.01.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 12/01/2021] [Accepted: 01/06/2022] [Indexed: 12/16/2022]
Abstract
The biophysical properties of existing optogenetic tools constrain the scale, speed, and fidelity of precise optogenetic control. Here, we use structure-guided mutagenesis to engineer opsins that exhibit very high potency while retaining fast kinetics. These new opsins enable large-scale, temporally and spatially precise control of population neural activity. We extensively benchmark these new opsins against existing optogenetic tools and provide a detailed biophysical characterization of a diverse family of opsins under two-photon illumination. This establishes a resource for matching the optimal opsin to the goals and constraints of patterned optogenetics experiments. Finally, by combining these new opsins with optimized procedures for holographic photostimulation, we demonstrate the simultaneous coactivation of several hundred spatially defined neurons with a single hologram and nearly double that number by temporally interleaving holograms at fast rates. These newly engineered opsins substantially extend the capabilities of patterned illumination optogenetic paradigms for addressing neural circuits and behavior.
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Affiliation(s)
- Savitha Sridharan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Marta A Gajowa
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Mora B Ogando
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Uday K Jagadisan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Lamiae Abdeladim
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Masato Sadahiro
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Hayley A Bounds
- The Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - William D Hendricks
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Toby S Turney
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Biophysics Graduate Program, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ian Tayler
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Karthika Gopakumar
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ian Antón Oldenburg
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Stephen G Brohawn
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; The Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Hillel Adesnik
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; The Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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19
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Tootoonian S, Schaefer AT, Latham PE. Sparse connectivity for MAP inference in linear models using sister mitral cells. PLoS Comput Biol 2022; 18:e1009808. [PMID: 35100264 PMCID: PMC8830798 DOI: 10.1371/journal.pcbi.1009808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 02/10/2022] [Accepted: 01/05/2022] [Indexed: 11/19/2022] Open
Abstract
Sensory processing is hard because the variables of interest are encoded in spike trains in a relatively complex way. A major goal in studies of sensory processing is to understand how the brain extracts those variables. Here we revisit a common encoding model in which variables are encoded linearly. Although there are typically more variables than neurons, this problem is still solvable because only a small number of variables appear at any one time (sparse prior). However, previous solutions require all-to-all connectivity, inconsistent with the sparse connectivity seen in the brain. Here we propose an algorithm that provably reaches the MAP (maximum a posteriori) inference solution, but does so using sparse connectivity. Our algorithm is inspired by the circuit of the mouse olfactory bulb, but our approach is general enough to apply to other modalities. In addition, it should be possible to extend it to nonlinear encoding models.
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Affiliation(s)
- Sina Tootoonian
- Gatsby Computational Neuroscience Unit, University College London, London, United Kingdom
- Sensory Circuits and Neurotechnology Laboratory, The Francis Crick Institute, London, United Kingdom
- * E-mail:
| | - Andreas T. Schaefer
- Sensory Circuits and Neurotechnology Laboratory, The Francis Crick Institute, London, United Kingdom
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Peter E. Latham
- Gatsby Computational Neuroscience Unit, University College London, London, United Kingdom
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20
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Maset A, Albanesi M, di Soccio A, Canova M, dal Maschio M, Lodovichi C. Aberrant Patterns of Sensory-Evoked Activity in the Olfactory Bulb of LRRK2 Knockout Mice. Cells 2021; 10:3212. [PMID: 34831434 PMCID: PMC8622670 DOI: 10.3390/cells10113212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/10/2021] [Accepted: 11/12/2021] [Indexed: 12/13/2022] Open
Abstract
The LRRK2 gene is the major genetic determinant of familiar Parkinson's disease (PD). Leucine-rich repeat kinase 2 (LRRK2) is a multidomain protein involved in several intracellular signaling pathways. A wealth of evidence indicates that LRRK2 is enriched at the presynaptic compartment where it regulates vesicle trafficking and neurotransmitter release. However, whether the role of LRRK2 affects neuronal networks dynamic at systems level remains unknown. Addressing this question is critical to unravel the impact of LRRK2 on brain function. Here, combining behavioral tests, electrophysiological recordings, and functional imaging, we investigated neuronal network dynamics, in vivo, in the olfactory bulb of mice carrying a null mutation in LRRK2 gene (LRRK2 knockout, LRRK2 KO, mice). We found that LRRK2 KO mice exhibit olfactory behavioral deficits. At the circuit level, the lack of LRRK2 expression results in altered gamma rhythms and odorant-evoked activity with significant impairments, while the spontaneous activity exhibited limited alterations. Overall, our data in the olfactory bulb suggest that the multifaced role of LRRK2 has a strong impact at system level when the network is engaged in active sensory processing.
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Affiliation(s)
- Andrea Maset
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy; (A.M.); (M.A.); (A.d.S.)
- Padova Neuroscience Center (PNC), Università degli Studi di Padova Via Orus 2, 35129 Padova, Italy; (M.C.); (M.d.M.)
| | - Marco Albanesi
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy; (A.M.); (M.A.); (A.d.S.)
- Padova Neuroscience Center (PNC), Università degli Studi di Padova Via Orus 2, 35129 Padova, Italy; (M.C.); (M.d.M.)
| | - Antonio di Soccio
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy; (A.M.); (M.A.); (A.d.S.)
- Padova Neuroscience Center (PNC), Università degli Studi di Padova Via Orus 2, 35129 Padova, Italy; (M.C.); (M.d.M.)
| | - Martina Canova
- Padova Neuroscience Center (PNC), Università degli Studi di Padova Via Orus 2, 35129 Padova, Italy; (M.C.); (M.d.M.)
| | - Marco dal Maschio
- Padova Neuroscience Center (PNC), Università degli Studi di Padova Via Orus 2, 35129 Padova, Italy; (M.C.); (M.d.M.)
- Department of Biomedical Sciences-UNIPD, Università degli Studi di Padova, Via U. Bassi 58B, 35121 Padova, Italy
| | - Claudia Lodovichi
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy; (A.M.); (M.A.); (A.d.S.)
- Padova Neuroscience Center (PNC), Università degli Studi di Padova Via Orus 2, 35129 Padova, Italy; (M.C.); (M.d.M.)
- Institute of Neuroscience-CNR, Viale G. Colombo 3, 35121 Padova, Italy
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21
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Adesnik H, Abdeladim L. Probing neural codes with two-photon holographic optogenetics. Nat Neurosci 2021; 24:1356-1366. [PMID: 34400843 PMCID: PMC9793863 DOI: 10.1038/s41593-021-00902-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/30/2021] [Indexed: 02/07/2023]
Abstract
Optogenetics ushered in a revolution in how neuroscientists interrogate brain function. Because of technical limitations, the majority of optogenetic studies have used low spatial resolution activation schemes that limit the types of perturbations that can be made. However, neural activity manipulations at finer spatial scales are likely to be important to more fully understand neural computation. Spatially precise multiphoton holographic optogenetics promises to address this challenge and opens up many new classes of experiments that were not previously possible. More specifically, by offering the ability to recreate extremely specific neural activity patterns in both space and time in functionally defined ensembles of neurons, multiphoton holographic optogenetics could allow neuroscientists to reveal fundamental aspects of the neural codes for sensation, cognition and behavior that have been beyond reach. This Review summarizes recent advances in multiphoton holographic optogenetics that substantially expand its capabilities, highlights outstanding technical challenges and provides an overview of the classes of experiments it can execute to test and validate key theoretical models of brain function. Multiphoton holographic optogenetics could substantially accelerate the pace of neuroscience discovery by helping to close the loop between experimental and theoretical neuroscience, leading to fundamental new insights into nervous system function and disorder.
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22
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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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23
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Heinbockel T, Straiker A. Cannabinoids Regulate Sensory Processing in Early Olfactory and Visual Neural Circuits. Front Neural Circuits 2021; 15:662349. [PMID: 34305536 PMCID: PMC8294086 DOI: 10.3389/fncir.2021.662349] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/11/2021] [Indexed: 12/25/2022] Open
Abstract
Our sensory systems such as the olfactory and visual systems are the target of neuromodulatory regulation. This neuromodulation starts at the level of sensory receptors and extends into cortical processing. A relatively new group of neuromodulators includes cannabinoids. These form a group of chemical substances that are found in the cannabis plant. Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the main cannabinoids. THC acts in the brain and nervous system like the chemical substances that our body produces, the endogenous cannabinoids or endocannabinoids, also nicknamed the brain's own cannabis. While the function of the endocannabinoid system is understood fairly well in limbic structures such as the hippocampus and the amygdala, this signaling system is less well understood in the olfactory pathway and the visual system. Here, we describe and compare endocannabinoids as signaling molecules in the early processing centers of the olfactory and visual system, the olfactory bulb, and the retina, and the relevance of the endocannabinoid system for synaptic plasticity.
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Affiliation(s)
- Thomas Heinbockel
- Department of Anatomy, Howard University College of Medicine, Washington, DC, United States
| | - Alex Straiker
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States
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24
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An engineered channelrhodopsin optimized for axon terminal activation and circuit mapping. Commun Biol 2021; 4:461. [PMID: 33846537 PMCID: PMC8042110 DOI: 10.1038/s42003-021-01977-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 03/11/2021] [Indexed: 11/09/2022] Open
Abstract
Optogenetic tools such as channelrhodopsin-2 (ChR2) enable the manipulation and mapping of neural circuits. However, ChR2 variants selectively transported down a neuron’s long-range axonal projections for precise presynaptic activation remain lacking. As a result, ChR2 activation is often contaminated by the spurious activation of en passant fibers that compromise the accurate interpretation of functional effects. Here, we explored the engineering of a ChR2 variant specifically localized to presynaptic axon terminals. The metabotropic glutamate receptor 2 (mGluR2) C-terminal domain fused with a proteolytic motif and axon-targeting signal (mGluR2-PA tag) localized ChR2-YFP at axon terminals without disturbing normal transmission. mGluR2-PA-tagged ChR2 evoked transmitter release in distal projection areas enabling lower levels of photostimulation. Circuit connectivity mapping in vivo with the Spike Collision Test revealed that mGluR2-PA-tagged ChR2 is useful for identifying axonal projection with significant reduction in the polysynaptic excess noise. These results suggest that the mGluR2-PA tag helps actuate trafficking to the axon terminal, thereby providing abundant possibilities for optogenetic experiments. Hamada et al. engineer and utilise a channelrhodopsin-2 variant that is localized to presynaptic axon terminals. They demonstrate its use for circuitry mapping in vivo and thus provide a useful tool for future optogenetic experiments
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25
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Chockanathan U, Crosier EJW, Waddle S, Lyman E, Gerkin RC, Padmanabhan K. Changes in pairwise correlations during running reshape global network state in the main olfactory bulb. J Neurophysiol 2021; 125:1612-1623. [PMID: 33656931 DOI: 10.1152/jn.00464.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neural codes for sensory inputs have been hypothesized to reside in a broader space defined by ongoing patterns of spontaneous activity. To understand the structure of this spontaneous activity in the olfactory system, we performed high-density recordings of neural populations in the main olfactory bulb of awake mice. We observed changes in pairwise correlations of spontaneous activity between mitral and tufted (M/T) cells when animals were running, which resulted in an increase in the entropy of the population. Surprisingly, pairwise maximum entropy models that described the population activity using only assumptions about the firing rates and correlations of neurons were better at predicting the global structure of activity when animals were stationary as compared to when they were running, implying that higher order (3rd, 4th order) interactions governed population activity during locomotion. Taken together, we found that locomotion alters the functional interactions that shape spontaneous population activity at the earliest stages of olfactory processing, one synapse away from the sensory receptors in the nasal epithelium. These data suggest that the coding space available for sensory representations responds adaptively to the animal's behavioral state.NEW & NOTEWORTHY The organization and structure of spontaneous population activity in the olfactory system places constraints of how odor information is represented. Using high-density electrophysiological recordings of mitral and tufted cells, we found that running increases the dimensionality of spontaneous activity, implicating higher order interactions among neurons during locomotion. Behavior, thus, flexibly alters neuronal activity at the earliest stages of sensory processing.
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Affiliation(s)
- Udaysankar Chockanathan
- Medical Scientist Training Program (MSTP), University of Rochester School of Medicine, Rochester, New York.,Department of Neuroscience and Neuroscience Graduate Program (NGP), University of Rochester School of Medicine, Rochester, New York
| | - Emily J W Crosier
- Department of Neuroscience and Neuroscience Graduate Program (NGP), University of Rochester School of Medicine, Rochester, New York
| | - Spencer Waddle
- Department of Physics, University of Delaware, Newark, Delaware
| | - Edward Lyman
- Department of Physics, University of Delaware, Newark, Delaware
| | - Richard C Gerkin
- School of Life Sciences, Arizona State University, Tempe, Arizona
| | - Krishnan Padmanabhan
- Medical Scientist Training Program (MSTP), University of Rochester School of Medicine, Rochester, New York.,Department of Neuroscience and Neuroscience Graduate Program (NGP), University of Rochester School of Medicine, Rochester, New York.,Center for Visual Sciences, University of Rochester School of Medicine, Rochester, New York
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26
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Qiu Q, Wu Y, Ma L, Yu CR. Encoding innately recognized odors via a generalized population code. Curr Biol 2021; 31:1813-1825.e4. [PMID: 33651991 PMCID: PMC8119320 DOI: 10.1016/j.cub.2021.01.094] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 12/25/2020] [Accepted: 01/27/2021] [Indexed: 01/19/2023]
Abstract
Odors carrying intrinsic values often trigger instinctive aversive or attractive responses. It is not known how innate valence is encoded. An intuitive model suggests that the information is conveyed through specific channels in hardwired circuits along the olfactory pathway, insulated from influences of other odors, to trigger innate responses. Here, we show that in mice, mixing innately aversive or attractive odors with a neutral odor and, surprisingly, mixing two odors with the same valence, abolish the innate behavioral responses. Recordings from the olfactory bulb indicate that odors are not masked at the level of peripheral activation and glomeruli independently encode components in the mixture. In contrast, crosstalk among the mitral and tufted (M/T) cells changes their patterns of activity such that those elicited by the mixtures can no longer be linearly decoded as separate components. The changes in behavioral and M/T cell responses are associated with reduced activation of brain areas linked to odor preferences. Thus, crosstalk among odor channels at the earliest processing stage in the olfactory pathway leads to re-coding of odor identity to abolish valence associated with the odors. These results are inconsistent with insulated labeled lines and support a model of a common mechanism of odor recognition for both innate and learned valence associations.
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Affiliation(s)
- Qiang Qiu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Yunming Wu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Limei Ma
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - C Ron Yu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA.
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27
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Abstract
Optical manipulation is a powerful way to control neural activity in vitro and in vivo with millisecond precision. Patterning of light provides the remarkable ability to simultaneously target spatially segregated neurons from a population. Commercially available projectors provide one of the simplest and most economical ways of achieving spatial light modulation at millisecond timescales. Here, we describe the protocol for constructing a projector-based spatio-temporal light patterning system integrated with a microscope on a typical electrophysiology rig. The set-up is well suited for applications requiring rapid, distinct, and combinatorial inputs, akin to brain activity. This equipment involved is fairly economical (<$5000 including all optical and mechanical components), and the set-up is easy to assemble and program.
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Affiliation(s)
- Aanchal Bhatia
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore, Karnataka, India
| | - Sahil Moza
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore, Karnataka, India
| | - Upinder S Bhalla
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore, Karnataka, India.
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28
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Topographically Distinct Projection Patterns of Early-Generated and Late-Generated Projection Neurons in the Mouse Olfactory Bulb. eNeuro 2020; 7:ENEURO.0369-20.2020. [PMID: 33158934 PMCID: PMC7716433 DOI: 10.1523/eneuro.0369-20.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 10/11/2020] [Accepted: 10/16/2020] [Indexed: 12/23/2022] Open
Abstract
In the mouse brain, olfactory information is transmitted to the olfactory cortex via olfactory bulb (OB) projection neurons known as mitral and tufted cells. Although mitral and tufted cells share many cellular characteristics, these cell types are distinct in their somata location and in their axonal and dendritic projection patterns. Moreover, mitral cells consist of heterogeneous subpopulations. In the mouse brain, olfactory information is transmitted to the olfactory cortex via olfactory bulb (OB) projection neurons known as mitral and tufted cells. Although mitral and tufted cells share many cellular characteristics, these cell types are distinct in their somata location and in their axonal and dendritic projection patterns. Moreover, mitral cells consist of heterogeneous subpopulations. We have previously shown that mitral cells generated at different embryonic days differentially localize within the mitral cell layer (MCL) and extend their lateral dendrites to different sublayers of the external plexiform layer (EPL). Here, we examined the axonal projection patterns from the subpopulations of OB projection neurons that are determined by the timing of neurogenesis (neuronal birthdate) to understand the developmental origin of the diversity in olfactory pathways. We separately labeled early-generated and late-generated OB projection neurons using in utero electroporation performed at embryonic day (E)11 and E12, respectively, and quantitatively analyzed their axonal projection patterns in the whole mouse brain using high-resolution 3D imaging. In this study, we demonstrate that the axonal projection of late-generated OB projection neurons is restricted to the anterior portion of the olfactory cortex while those of the early-generated OB projection neurons innervate the entire olfactory cortex. Our results suggest that the late-generated mitral cells do not extend their axons to the posterior regions of the olfactory cortex. Therefore, the mitral cells having different birthdates differ, not only in cell body location and dendritic projections within the OB, but also in their axonal projection pattern to the olfactory cortex.
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29
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Wu Y, Dal Maschio M, Kubo F, Baier H. An Optical Illusion Pinpoints an Essential Circuit Node for Global Motion Processing. Neuron 2020; 108:722-734.e5. [PMID: 32966764 DOI: 10.1016/j.neuron.2020.08.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 07/21/2020] [Accepted: 08/26/2020] [Indexed: 11/16/2022]
Abstract
Direction-selective (DS) neurons compute the direction of motion in a visual scene. Brain-wide imaging in larval zebrafish has revealed hundreds of DS neurons scattered throughout the brain. However, the exact population that causally drives motion-dependent behaviors-e.g., compensatory eye and body movements-remains largely unknown. To identify the behaviorally relevant population of DS neurons, here we employ the motion aftereffect (MAE), which causes the well-known "waterfall illusion." Together with region-specific optogenetic manipulations and cellular-resolution functional imaging, we found that MAE-responsive neurons represent merely a fraction of the entire population of DS cells in larval zebrafish. They are spatially clustered in a nucleus in the ventral lateral pretectal area and are necessary and sufficient to steer the entire cycle of optokinetic eye movements. Thus, our illusion-based behavioral paradigm, combined with optical imaging and optogenetics, identified key circuit elements of global motion processing in the vertebrate brain.
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Affiliation(s)
- Yunmin Wu
- Department Genes - Circuits - Behavior, Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Marco Dal Maschio
- Department Genes - Circuits - Behavior, Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany; Department of Biomedical Sciences, University of Padua, Via 8 Febbraio, 2, 35122 Padova, Italy
| | - Fumi Kubo
- Department Genes - Circuits - Behavior, Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany; Center for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
| | - Herwig Baier
- Department Genes - Circuits - Behavior, Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany
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30
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Imamura F, Ito A, LaFever BJ. Subpopulations of Projection Neurons in the Olfactory Bulb. Front Neural Circuits 2020; 14:561822. [PMID: 32982699 PMCID: PMC7485133 DOI: 10.3389/fncir.2020.561822] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/12/2020] [Indexed: 12/17/2022] Open
Abstract
Generation of neuronal diversity is a biological strategy widely used in the brain to process complex information. The olfactory bulb is the first relay station of olfactory information in the vertebrate central nervous system. In the olfactory bulb, axons of the olfactory sensory neurons form synapses with dendrites of projection neurons that transmit the olfactory information to the olfactory cortex. Historically, the olfactory bulb projection neurons have been classified into two populations, mitral cells and tufted cells. The somata of these cells are distinctly segregated within the layers of the olfactory bulb; the mitral cells are located in the mitral cell layer while the tufted cells are found in the external plexiform layer. Although mitral and tufted cells share many morphological, biophysical, and molecular characteristics, they differ in soma size, projection patterns of their dendrites and axons, and odor responses. In addition, tufted cells are further subclassified based on the relative depth of their somata location in the external plexiform layer. Evidence suggests that different types of tufted cells have distinct cellular properties and play different roles in olfactory information processing. Therefore, mitral and different types of tufted cells are considered as starting points for parallel pathways of olfactory information processing in the brain. Moreover, recent studies suggest that mitral cells also consist of heterogeneous subpopulations with different cellular properties despite the fact that the mitral cell layer is a single-cell layer. In this review, we first compare the morphology of projection neurons in the olfactory bulb of different vertebrate species. Next, we explore the similarities and differences among subpopulations of projection neurons in the rodent olfactory bulb. We also discuss the timing of neurogenesis as a factor for the generation of projection neuron heterogeneity in the olfactory bulb. Knowledge about the subpopulations of olfactory bulb projection neurons will contribute to a better understanding of the complex olfactory information processing in higher brain regions.
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Affiliation(s)
- Fumiaki Imamura
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, United States
| | - Ayako Ito
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, United States
| | - Brandon J LaFever
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, United States
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31
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Bolding KA, Nagappan S, Han BX, Wang F, Franks KM. Recurrent circuitry is required to stabilize piriform cortex odor representations across brain states. eLife 2020; 9:e53125. [PMID: 32662420 PMCID: PMC7360366 DOI: 10.7554/elife.53125] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 06/19/2020] [Indexed: 11/13/2022] Open
Abstract
Pattern completion, or the ability to retrieve stable neural activity patterns from noisy or partial cues, is a fundamental feature of memory. Theoretical studies indicate that recurrently connected auto-associative or discrete attractor networks can perform this process. Although pattern completion and attractor dynamics have been observed in various recurrent neural circuits, the role recurrent circuitry plays in implementing these processes remains unclear. In recordings from head-fixed mice, we found that odor responses in olfactory bulb degrade under ketamine/xylazine anesthesia while responses immediately downstream, in piriform cortex, remain robust. Recurrent connections are required to stabilize cortical odor representations across states. Moreover, piriform odor representations exhibit attractor dynamics, both within and across trials, and these are also abolished when recurrent circuitry is eliminated. Here, we present converging evidence that recurrently-connected piriform populations stabilize sensory representations in response to degraded inputs, consistent with an auto-associative function for piriform cortex supported by recurrent circuitry.
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Affiliation(s)
- Kevin A Bolding
- Department of Neurobiology, Duke University Medical SchoolDurhamUnited States
| | | | - Bao-Xia Han
- Department of Neurobiology, Duke University Medical SchoolDurhamUnited States
| | - Fan Wang
- Department of Neurobiology, Duke University Medical SchoolDurhamUnited States
| | - Kevin M Franks
- Department of Neurobiology, Duke University Medical SchoolDurhamUnited States
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32
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Chong E, Moroni M, Wilson C, Shoham S, Panzeri S, Rinberg D. Manipulating synthetic optogenetic odors reveals the coding logic of olfactory perception. Science 2020; 368:368/6497/eaba2357. [PMID: 32554567 DOI: 10.1126/science.aba2357] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 05/01/2020] [Indexed: 12/26/2022]
Abstract
How does neural activity generate perception? Finding the combinations of spatial or temporal activity features (such as neuron identity or latency) that are consequential for perception remains challenging. We trained mice to recognize synthetic odors constructed from parametrically defined patterns of optogenetic activation, then measured perceptual changes during extensive and controlled perturbations across spatiotemporal dimensions. We modeled recognition as the matching of patterns to learned templates. The templates that best predicted recognition were sequences of spatially identified units, ordered by latencies relative to each other (with minimal effects of sniff). Within templates, individual units contributed additively, with larger contributions from earlier-activated units. Our synthetic approach reveals the fundamental logic of the olfactory code and provides a general framework for testing links between sensory activity and perception.
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Affiliation(s)
- Edmund Chong
- Neuroscience Institute, NYU Langone Health, New York, NY 10016, USA.
| | - Monica Moroni
- Neural Computation Laboratory, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy. .,CIMeC, University of Trento, Rovereto, Italy
| | | | - Shy Shoham
- Neuroscience Institute, NYU Langone Health, New York, NY 10016, USA.,Center for Neural Science, New York University, New York, NY 10003, USA.,Tech4Health Institute, NYU Langone Health, New York, NY 10010, USA.,Department of Ophthalmology, NYU Langone Health, New York, NY 10017, USA
| | - Stefano Panzeri
- Neural Computation Laboratory, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy
| | - Dmitry Rinberg
- Neuroscience Institute, NYU Langone Health, New York, NY 10016, USA. .,Center for Neural Science, New York University, New York, NY 10003, USA
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33
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Differential Impacts of Repeated Sampling on Odor Representations by Genetically-Defined Mitral and Tufted Cell Subpopulations in the Mouse Olfactory Bulb. J Neurosci 2020; 40:6177-6188. [PMID: 32601245 DOI: 10.1523/jneurosci.0258-20.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 06/16/2020] [Accepted: 06/18/2020] [Indexed: 12/20/2022] Open
Abstract
Sniffing, the active control of breathing beyond passive respiration, is used by mammals to modulate olfactory sampling. Sniffing allows animals to make odor-guided decisions within ∼200 ms, but animals routinely engage in bouts of high-frequency sniffing spanning several seconds; the impact of such repeated odorant sampling on odor representations remains unclear. We investigated this question in the mouse olfactory bulb (OB), where mitral and tufted cells (MTCs) form parallel output streams of odor information processing. To test the impact of repeated odorant sampling on MTC responses, we used two-photon imaging in anesthetized male and female mice to record activation of MTCs while precisely varying inhalation frequency. A combination of genetic targeting and viral expression of GCaMP6 reporters allowed us to access mitral cell (MC) and superficial tufted cell (sTC) subpopulations separately. We found that repeated odorant sampling differentially affected responses in MCs and sTCs, with MCs showing more diversity than sTCs over the same time period. Impacts of repeated sampling among MCs included both increases and decreases in excitation, as well as changes in response polarity. Response patterns across simultaneously-imaged MCs reformatted over time, with representations of different odorants becoming more distinct. Individual MCs responded differentially to changes in inhalation frequency, whereas sTC responses were more uniform over time and across frequency. Our results support the idea that MCs and TCs comprise functionally distinct pathways for odor information processing, and suggest that the reformatting of MC odor representations by high-frequency sniffing may serve to enhance the discrimination of similar odors.SIGNIFICANCE STATEMENT Repeated sampling of odorants during high-frequency respiration (sniffing) is a hallmark of active odorant sampling by mammals; however, the adaptive function of this behavior remains unclear. We found distinct effects of repeated sampling on odor representations carried by the two main output channels from the mouse olfactory bulb (OB), mitral and tufted cells (MTCs). Mitral cells (MCs) showed more diverse changes in response patterns over time as compared with tufted cells (TCs), leading to odorant representations that were more distinct after repeated sampling. These results support the idea that MTCs contribute different aspects to encoding odor information, and they indicate that MCs (but not TCs) may play a primary role in the modulation of olfactory processing by sampling behavior.
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34
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Effect of Circuit Structure on Odor Representation in the Insect Olfactory System. eNeuro 2020; 7:ENEURO.0130-19.2020. [PMID: 32345734 PMCID: PMC7292731 DOI: 10.1523/eneuro.0130-19.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 02/10/2020] [Accepted: 02/23/2020] [Indexed: 11/30/2022] Open
Abstract
In neuroscience, the structure of a circuit has often been used to intuit function—an inversion of Louis Kahn’s famous dictum, “Form follows function” (Kristan and Katz, 2006). However, different brain networks may use different network architectures to solve the same problem. The olfactory circuits of two insects, the locust, Schistocerca americana, and the fruit fly, Drosophila melanogaster, serve the same function—to identify and discriminate odors. The neural circuitry that achieves this shows marked structural differences. Projection neurons (PNs) in the antennal lobe innervate Kenyon cells (KCs) of the mushroom body. In locust, each KC receives inputs from ∼50% of PNs, a scheme that maximizes the difference between inputs to any two of ∼50,000 KCs. In contrast, in Drosophila, this number is only 5% and appears suboptimal. Using a computational model of the olfactory system, we show that the activity of KCs is sufficiently high-dimensional that it can separate similar odors regardless of the divergence of PN–KC connections. However, when temporal patterning encodes odor attributes, dense connectivity outperforms sparse connections. Increased separability comes at the cost of reliability. The disadvantage of sparse connectivity can be mitigated by incorporating other aspects of circuit architecture seen in Drosophila. Our simulations predict that Drosophila and locust circuits lie at different ends of a continuum where the Drosophila gives up on the ability to resolve similar odors to generalize across varying environments, while the locust separates odor representations but risks misclassifying noisy variants of the same odor.
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35
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Homma R, Nagayama S. A Prism Method for Optical Glomerular Mapping of the Medial Olfactory Bulb in Mice. Front Neural Circuits 2020; 13:79. [PMID: 31920566 PMCID: PMC6933389 DOI: 10.3389/fncir.2019.00079] [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: 10/11/2019] [Accepted: 12/06/2019] [Indexed: 11/13/2022] Open
Abstract
The processing of odor input in the brain begins in the olfactory bulb (OB), where odor information is represented by combinations of active glomeruli. Each glomerulus is associated with a specific odorant receptor type, of which there are ~1,000 in mice; thus different odors activate different subsets of glomeruli. Most receptor types have duplicate lateral and medial glomeruli in each of the left and right OBs. The two sets of glomeruli form separate but mirror-symmetric glomerular maps. It is not known whether the odor representations in these paired maps are exact copies of each other or potentially encode additional information. Previous studies of glomerular odor representations were mostly limited to the lateral map because the medial map is inaccessible with high-resolution activity mapping techniques, such as optical imaging. To address this, we developed a method for optical imaging of the medial bulb by replacing the contralateral bulb with a right-angle prism that has a mirror coating on the hypotenuse. With this method, we performed calcium imaging of corresponding subsets of glomeruli in the lateral map at the dorsal surface and the medial map at the medial wall. Thus, we demonstrate an experimental model system for comparing odor representations in these redundant sensory maps, enabling a better understanding of the role of paired maps and the neuronal coding of odor stimuli.
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Affiliation(s)
- Ryota Homma
- Department of Neurobiology & Anatomy, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Shin Nagayama
- Department of Neurobiology & Anatomy, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
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36
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Targeted Cortical Manipulation of Auditory Perception. Neuron 2019; 104:1168-1179.e5. [PMID: 31727548 PMCID: PMC6926484 DOI: 10.1016/j.neuron.2019.09.043] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 07/25/2019] [Accepted: 09/24/2019] [Indexed: 11/27/2022]
Abstract
Driving perception by direct activation of neural ensembles in cortex is a necessary step for achieving a causal understanding of the neural code for auditory perception and developing central sensory rehabilitation methods. Here, using optogenetic manipulations during an auditory discrimination task in mice, we show that auditory cortex can be short-circuited by coarser pathways for simple sound identification. Yet when the sensory decision becomes more complex, involving temporal integration of information, auditory cortex activity is required for sound discrimination and targeted activation of specific cortical ensembles changes perceptual decisions, as predicted by our readout of the cortical code. Hence, auditory cortex representations contribute to sound discriminations by refining decisions from parallel routes. Auditory cortex is dispensable for discrimination of dissimilar pure tones in mice Auditory cortex is involved in a sound discrimination requiring temporal integration Focal cortical activations bias choices in cortex-dependent discriminations Discrimination is faster for pure tones than for optogenetic cortical activations
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37
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Scholl B, Wilson DE, Jaepel J, Fitzpatrick D. Functional Logic of Layer 2/3 Inhibitory Connectivity in the Ferret Visual Cortex. Neuron 2019; 104:451-457.e3. [PMID: 31495646 DOI: 10.1016/j.neuron.2019.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 05/29/2019] [Accepted: 08/01/2019] [Indexed: 10/26/2022]
Abstract
Understanding how cortical inhibition shapes circuit function requires identifying the connectivity rules relating the response properties of inhibitory interneurons and their postsynaptic targets. Here we explore the orientation tuning of layer 2/3 inhibitory inputs in the ferret visual cortex using a combination of in vivo axon imaging, functional input mapping, and physiology. Inhibitory boutons exhibit robust orientation-tuned responses with preferences that can differ significantly from the cortical column in which they reside. Inhibitory input fields measured with patterned optogenetic stimulation and intracellular recordings revealed that these inputs originate from a wide range of orientation domains, inconsistent with a model of co-tuned inhibition and excitation. Intracellular synaptic conductance measurements confirm that individual neurons can depart from a co-tuned regime. Our results argue against a simple rule for the arrangement of inhibitory inputs supplied by layer 2/3 circuits and suggest that heterogeneity in presynaptic inhibitory networks contributes to neural response properties.
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Affiliation(s)
- Benjamin Scholl
- Max Planck Florida Institute for Neuroscience, 1 Max Planck Way, Jupiter, FL 33458, USA.
| | | | - Juliane Jaepel
- Max Planck Florida Institute for Neuroscience, 1 Max Planck Way, Jupiter, FL 33458, USA
| | - David Fitzpatrick
- Max Planck Florida Institute for Neuroscience, 1 Max Planck Way, Jupiter, FL 33458, USA
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38
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Storace DA, Cohen LB, Choi Y. Using Genetically Encoded Voltage Indicators (GEVIs) to Study the Input-Output Transformation of the Mammalian Olfactory Bulb. Front Cell Neurosci 2019; 13:342. [PMID: 31417362 PMCID: PMC6684792 DOI: 10.3389/fncel.2019.00342] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 07/11/2019] [Indexed: 12/19/2022] Open
Abstract
Genetically encoded voltage indicators (GEVIs) are fluorescent protein reporters of membrane potential. These tools can, in principle, be used to monitor the neural activity of genetically distinct cell types in the brain. Although introduced in 1997, they have been a challenge to use to study intact neural circuits due to a combination of small signal-to-noise ratio, slow kinetics, and poor membrane expression. New strategies have yielded novel GEVIs such as ArcLight, which have improved properties. Here, we compare the in vivo properties of ArcLight with Genetically Encoded Calcium Indicators (GECIs) in the mouse olfactory bulb. We show how voltage imaging can be combined with organic calcium sensitive dyes to measure the input-output transformation of the olfactory bulb. Finally, we demonstrate that ArcLight can be targeted to olfactory bulb interneurons. The olfactory bulb contributes substantially to the perception of the concentration invariance of odor recognition.
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Affiliation(s)
- Douglas A Storace
- Department of Biological Science, Florida State University, Tallahassee, FL, United States.,Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Lawrence B Cohen
- Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States.,Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, South Korea
| | - Yunsook Choi
- Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States.,Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, South Korea
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39
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Chae H, Kepple DR, Bast WG, Murthy VN, Koulakov AA, Albeanu DF. Mosaic representations of odors in the input and output layers of the mouse olfactory bulb. Nat Neurosci 2019; 22:1306-1317. [PMID: 31332371 DOI: 10.1038/s41593-019-0442-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/30/2019] [Indexed: 11/09/2022]
Abstract
The elementary stimulus features encoded by the olfactory system remain poorly understood. We examined the relationship between 1,666 physical-chemical descriptors of odors and the activity of olfactory bulb inputs and outputs in awake mice. Glomerular and mitral and tufted cell responses were sparse and locally heterogeneous, with only a weak dependence of their positions on physical-chemical properties. Odor features represented by ensembles of mitral and tufted cells were overlapping but distinct from those represented in glomeruli, which is consistent with an extensive interplay between feedforward and feedback inputs to the bulb. This reformatting was well described as a rotation in odor space. The physical-chemical descriptors accounted for a small fraction in response variance, and the similarity of odors in the physical-chemical space was a poor predictor of similarity in neuronal representations. Our results suggest that commonly used physical-chemical properties are not systematically represented in bulbar activity and encourage further searches for better descriptors of odor space.
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Affiliation(s)
- Honggoo Chae
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Daniel R Kepple
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.,Watson School for Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Walter G Bast
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Venkatesh N Murthy
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Alexei A Koulakov
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. .,Watson School for Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
| | - Dinu F Albeanu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. .,Watson School for Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
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40
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Scaling Principles of Distributed Circuits. Curr Biol 2019; 29:2533-2540.e7. [PMID: 31327712 DOI: 10.1016/j.cub.2019.06.046] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/21/2019] [Accepted: 06/17/2019] [Indexed: 12/17/2022]
Abstract
Identifying shared quantitative features of a neural circuit across species is important for 3 reasons. Often expressed in the form of power laws and called scaling relationships [1, 2], they reveal organizational principles of circuits, make insights gleaned from model systems widely applicable, and explain circuit performance and function, e.g., visual circuits [3, 4]. The visual circuit is topographic [5, 6], wherein retinal neurons target and activate predictable spatial loci in primary visual cortex. The brain, however, contains many circuits, where neuronal targets and activity are unpredictable and distributed throughout the circuit, e.g., olfactory circuits, in which glomeruli (or mitral cells) in the olfactory bulb synapse with neurons distributed throughout the piriform cortex [7-10]. It is unknown whether such circuits, which we term distributed circuits, are scalable. To determine whether distributed circuits scale, we obtained quantitative descriptions of the olfactory bulb and piriform cortex in six mammals using stereology techniques and light microscopy. Two conserved features provide evidence of scalability. First, the number of piriform neurons n and bulb glomeruli g scale as n∼g3/2. Second, the average number of synapses between a bulb glomerulus and piriform neuron is invariant at one. Using theory and modeling, we show that these two features preserve the discriminatory ability and precision of odor information across the olfactory circuit. As both abilities depend on circuit size, manipulating size provides evolution with a way to adapt a species to its niche without designing developmental programs de novo. These principles might apply to other distributed circuits like the hippocampus.
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Temporal Dynamics of Inhalation-Linked Activity across Defined Subpopulations of Mouse Olfactory Bulb Neurons Imaged In Vivo. eNeuro 2019; 6:ENEURO.0189-19.2019. [PMID: 31209151 PMCID: PMC6597857 DOI: 10.1523/eneuro.0189-19.2019] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 05/23/2019] [Indexed: 11/21/2022] Open
Abstract
In mammalian olfaction, inhalation drives the temporal patterning of neural activity that underlies early olfactory processing. It remains poorly understood how the neural circuits that process incoming olfactory information are engaged in the context of inhalation-linked dynamics. Here, we used artificial inhalation and two-photon calcium imaging to compare the dynamics of activity evoked by odorant inhalation across major cell types of the mouse olfactory bulb (OB). We expressed GCaMP6f or jRGECO1a in mitral and tufted cell (MTC) subpopulations, olfactory sensory neurons (OSNs), and two major juxtaglomerular interneuron classes and imaged responses to a single inhalation of odorant. Activity in all cell types was strongly linked to inhalation, and all cell types showed some variance in the latency, rise times, and durations of their inhalation-linked response. Juxtaglomerular interneuron dynamics closely matched that of sensory inputs, while MTCs showed the highest diversity in responses, with a range of latencies and durations that could not be accounted for by heterogeneity in sensory input dynamics. Diversity was apparent even among “sister” tufted cells innervating the same glomerulus. Surprisingly, inhalation-linked responses of MTCs were highly overlapping and could not be distinguished on the basis of their inhalation-linked dynamics, with the exception of a subpopulation of superficial tufted cells expressing cholecystokinin (CCK). Our results are consistent with a model in which diversity in inhalation-linked patterning of OB output arises first at the level of sensory input and is enhanced by feedforward inhibition from juxtaglomerular interneurons which differentially impact different subpopulations of OB output neurons.
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Mohrhardt J, Nagel M, Fleck D, Ben-Shaul Y, Spehr M. Signal Detection and Coding in the Accessory Olfactory System. Chem Senses 2019; 43:667-695. [PMID: 30256909 PMCID: PMC6211456 DOI: 10.1093/chemse/bjy061] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In many mammalian species, the accessory olfactory system plays a central role in guiding behavioral and physiological responses to social and reproductive interactions. Because of its relatively compact structure and its direct access to amygdalar and hypothalamic nuclei, the accessory olfactory pathway provides an ideal system to study sensory control of complex mammalian behavior. During the last several years, many studies employing molecular, behavioral, and physiological approaches have significantly expanded and enhanced our understanding of this system. The purpose of the current review is to integrate older and newer studies to present an updated and comprehensive picture of vomeronasal signaling and coding with an emphasis on early accessory olfactory system processing stages. These include vomeronasal sensory neurons in the vomeronasal organ, and the circuitry of the accessory olfactory bulb. Because the overwhelming majority of studies on accessory olfactory system function employ rodents, this review is largely focused on this phylogenetic order, and on mice in particular. Taken together, the emerging view from both older literature and more recent studies is that the molecular, cellular, and circuit properties of chemosensory signaling along the accessory olfactory pathway are in many ways unique. Yet, it has also become evident that, like the main olfactory system, the accessory olfactory system also has the capacity for adaptive learning, experience, and state-dependent plasticity. In addition to describing what is currently known about accessory olfactory system function and physiology, we highlight what we believe are important gaps in our knowledge, which thus define exciting directions for future investigation.
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Affiliation(s)
- Julia Mohrhardt
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Aachen, Germany
| | - Maximilian Nagel
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Aachen, Germany
| | - David Fleck
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Aachen, Germany
| | - Yoram Ben-Shaul
- Department of Medical Neurobiology, School of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Marc Spehr
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Aachen, Germany
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Hattori R, Danskin B, Babic Z, Mlynaryk N, Komiyama T. Area-Specificity and Plasticity of History-Dependent Value Coding During Learning. Cell 2019; 177:1858-1872.e15. [PMID: 31080067 DOI: 10.1016/j.cell.2019.04.027] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 03/03/2019] [Accepted: 04/12/2019] [Indexed: 11/16/2022]
Abstract
Decision making is often driven by the subjective value of available options, a value which is formed through experience. To support this fundamental behavior, the brain must encode and maintain the subjective value. To investigate the area specificity and plasticity of value coding, we trained mice in a value-based decision task and imaged neural activity in 6 cortical areas with cellular resolution. History- and value-related signals were widespread across areas, but their strength and temporal patterns differed. In expert mice, the retrosplenial cortex (RSC) uniquely encoded history- and value-related signals with persistent population activity patterns across trials. This unique encoding of RSC emerged during task learning with a strong increase in more distant history signals. Acute inactivation of RSC selectively impaired the reward-history-based behavioral strategy. Our results indicate that RSC flexibly changes its history coding and persistently encodes value-related signals to support adaptive behaviors.
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Affiliation(s)
- Ryoma Hattori
- Neurobiology Section, Center for Neural Circuits and Behavior, Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA.
| | - Bethanny Danskin
- Neurobiology Section, Center for Neural Circuits and Behavior, Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA
| | - Zeljana Babic
- Neurobiology Section, Center for Neural Circuits and Behavior, Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA
| | - Nicole Mlynaryk
- Neurobiology Section, Center for Neural Circuits and Behavior, Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA
| | - Takaki Komiyama
- Neurobiology Section, Center for Neural Circuits and Behavior, Department of Neurosciences, and Halıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USA.
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Cortical recruitment determines learning dynamics and strategy. Nat Commun 2019; 10:1479. [PMID: 30931939 PMCID: PMC6443669 DOI: 10.1038/s41467-019-09450-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 03/12/2019] [Indexed: 12/26/2022] Open
Abstract
Salience is a broad and widely used concept in neuroscience whose neuronal correlates, however, remain elusive. In behavioral conditioning, salience is used to explain various effects, such as stimulus overshadowing, and refers to how fast and strongly a stimulus can be associated with a conditioned event. Here, we identify sounds of equal intensity and perceptual detectability, which due to their spectro-temporal content recruit different levels of population activity in mouse auditory cortex. When using these sounds as cues in a Go/NoGo discrimination task, the degree of cortical recruitment matches the salience parameter of a reinforcement learning model used to analyze learning speed. We test an essential prediction of this model by training mice to discriminate light-sculpted optogenetic activity patterns in auditory cortex, and verify that cortical recruitment causally determines association or overshadowing of the stimulus components. This demonstrates that cortical recruitment underlies major aspects of stimulus salience during reinforcement learning.
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Narrowly Confined and Glomerulus-Specific Onset Latencies of Odor-Evoked Calcium Transients in the Juxtaglomerular Cells of the Mouse Main Olfactory Bulb. eNeuro 2019; 6:eN-NWR-0387-18. [PMID: 30834302 PMCID: PMC6397951 DOI: 10.1523/eneuro.0387-18.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 02/01/2019] [Accepted: 02/05/2019] [Indexed: 12/04/2022] Open
Abstract
Odor information is transmitted from olfactory sensory neurons to principal neurons at the glomeruli of the olfactory bulb. The intraglomerular neuronal circuit also includes hundreds of interneurons referred to as juxtaglomerular (JG) cells. Stimulus selectivity is well correlated among many JG cells that are associated with the same glomerulus, consistent with their highly homogeneous sensory inputs. However, much less is known about the temporal aspects of their activity, including the temporal coordination of their odor-evoked responses. As many JG cells within a glomerular module respond to the same stimulus, the extent to which their activity is temporally aligned will affect the temporal profile of their population inhibitory inputs. Using random-access high-speed two-photon microscopy, we recorded the odor-evoked calcium transients of mouse JG cells and compared the onset latency and rise time among neurons putatively associated with the same and different glomeruli. Whereas the overall onset latencies of odor-evoked transients were distributed across a ∼150 ms time window, those from cells putatively associated with the same glomerulus were confined to a much narrower window of several tens of milliseconds. This result suggests that onset latency primarily depends on the associated glomerulus. We also observed glomerular specificity in the rise time. The glomerulus-specific temporal pattern of odor-evoked activity implies that the temporal patterns of inputs from the intraglomerular circuit are unique to individual glomerulus–odor pairs, which may contribute to efficient shaping of the temporal pattern of activity in the principal neurons.
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Shmuel R, Secundo L, Haddad R. Strong, weak and neuron type dependent lateral inhibition in the olfactory bulb. Sci Rep 2019; 9:1602. [PMID: 30733509 PMCID: PMC6367436 DOI: 10.1038/s41598-018-38151-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 12/11/2018] [Indexed: 11/29/2022] Open
Abstract
In many sensory systems, different sensory features are transmitted in parallel by several different types of output neurons. In the mouse olfactory bulb, there are only two output neuron types, the mitral and tufted cells (M/T), which receive similar odor inputs, but they are believed to transmit different odor characteristics. How these two neuron types deliver different odor information is unclear. Here, by combining electrophysiology and optogenetics, it is shown that distinct inhibitory networks modulate M/T cell responses differently. Overall strong lateral inhibition was scarce, with most neurons receiving lateral inhibition from a handful of unorganized surrounding glomeruli (~5% on average). However, there was a considerable variability between different neuron types in the strength and frequency of lateral inhibition. Strong lateral inhibition was mostly found in neurons locked to the first half of the respiration cycle. In contrast, weak inhibition arriving from many surrounding glomeruli was relatively more common in neurons locked to the late phase of the respiration cycle. Proximal neurons could receive different levels of inhibition. These results suggest that there is considerable diversity in the way M/T cells process odors so that even neurons that receive the same odor input transmit different odor information to the cortex.
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Affiliation(s)
- Ronit Shmuel
- Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Lavi Secundo
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Rafi Haddad
- Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel.
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Slankster E, Odell SR, Mathew D. Strength in diversity: functional diversity among olfactory neurons of the same type. J Bioenerg Biomembr 2019; 51:65-75. [PMID: 30604088 PMCID: PMC6382560 DOI: 10.1007/s10863-018-9779-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 11/13/2018] [Indexed: 01/01/2023]
Abstract
Most animals depend upon olfaction to find food, mates, and to avoid predators. An animal's olfactory circuit helps it sense its olfactory environment and generate critical behavioral responses. The general architecture of the olfactory circuit, which is conserved across species, is made up of a few different neuronal types including first-order receptor neurons, second- and third-order neurons, and local interneurons. Each neuronal type differs in their morphology, physiology, and neurochemistry. However, several recent studies have suggested that there is intrinsic diversity even among neurons of the same type and that this diversity is important for neural function. In this review, we first examine instances of intrinsic diversity observed among individual types of olfactory neurons. Next, we review potential genetic and experience-based plasticity mechanisms that underlie this diversity. Finally, we consider the implications of intrinsic neuronal diversity for circuit function. Overall, we hope to highlight the importance of intrinsic diversity as a previously underestimated property of circuit function.
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Affiliation(s)
- Eryn Slankster
- Department of Biology, University of Nevada, 1664 N. Virginia St., MS: 0314, Reno, NV, 89557, USA
| | - Seth R Odell
- Department of Biology, University of Nevada, 1664 N. Virginia St., MS: 0314, Reno, NV, 89557, USA
- Integrated Neuroscience Program, University of Nevada, Reno, NV, 89557, USA
| | - Dennis Mathew
- Department of Biology, University of Nevada, 1664 N. Virginia St., MS: 0314, Reno, NV, 89557, USA.
- Integrated Neuroscience Program, University of Nevada, Reno, NV, 89557, USA.
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Srinivasan S, Stevens CF. The distributed circuit within the piriform cortex makes odor discrimination robust. J Comp Neurol 2018; 526:2725-2743. [PMID: 30014545 DOI: 10.1002/cne.24492] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 05/30/2018] [Accepted: 06/01/2018] [Indexed: 12/14/2022]
Abstract
Distributed circuits wherein connections between subcircuit components seem randomly distributed are common to the olfactory circuit, hippocampus, and cerebellum. In such circuits, activation patterns seem random too, showing no detectable spatial preference, and contrast with regions that have topographic connections between subcircuits and topographic activation patterns. Quantitative studies of topographic circuits in the neocortex have yielded common principles of organization. Whether distributed circuits share similar principles of organization is unknown because similar quantitative information is missing and understanding the way they encode information remains a challenge. We addressed these needs by providing a quantitative description of the mouse piriform cortex, a paleocortical distributed circuit that subserves olfaction. The quantitative information provided two insights. First, with a nearly parameter-free model of the olfactory circuit, we show that the piriform cortex robustly maintains odor information and discrimination ability present in the olfactory bulb. Second, the paleocortex is quantitatively different from the neocortex: it has a lower surface area density, which decreases from the anterior to posterior paleocortex contrasting with the uniform neuronal density of the neocortex. These insights might also apply to other distributed circuits.
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Affiliation(s)
- Shyam Srinivasan
- Salk Institute for Biological Studies, La Jolla, California.,Kavli Institute for Brain and Mind, University of California, San Diego, California
| | - Charles F Stevens
- Salk Institute for Biological Studies, La Jolla, California.,Kavli Institute for Brain and Mind, University of California, San Diego, California
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Sparsened neuronal activity in an optogenetically activated olfactory glomerulus. Sci Rep 2018; 8:14955. [PMID: 30297851 PMCID: PMC6175855 DOI: 10.1038/s41598-018-33021-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 09/07/2018] [Indexed: 12/04/2022] Open
Abstract
Glomeruli are the functional units of olfactory information processing but little remains known about their individual unit function. This is due to their widespread activation by odor stimuli. We expressed channelrhodopsin-2 in a single olfactory sensory neuron type, and used laser stimulation and simultaneous in vivo calcium imaging to study the responses of a single glomerulus to optogenetic stimulation. Calcium signals in the neuropil of this glomerulus were representative of the sensory input and nearly identical if evoked by intensity-matched odor and laser stimuli. However, significantly fewer glomerular layer interneurons and olfactory bulb output neurons (mitral cells) responded to optogenetic versus odor stimuli, resulting in a small and spatially compact optogenetic glomerular unit response. Temporal features of laser stimuli were represented with high fidelity in the neuropil of the glomerulus and the mitral cells, but not in interneurons. Increases in laser stimulus intensity were encoded by larger signal amplitudes in all compartments of the glomerulus, and by the recruitment of additional interneurons and mitral cells. No spatial expansion of the glomerular unit response was observed in response to stronger input stimuli. Our data are among the first descriptions of input-output transformations in a selectively activated olfactory glomerulus.
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Wen D, Li Y, Zhu X, Chen M, Lu J, Li P. Selective photoactivation of neural activity combined with laser speckle imaging of cerebral blood flow. OPTICS LETTERS 2018; 43:3798-3801. [PMID: 30067682 DOI: 10.1364/ol.43.003798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 07/09/2018] [Indexed: 06/08/2023]
Abstract
Neural activity leads to alterations in cerebral blood flow (CBF), i.e., neurovascular regulation, which is implicated in brain physiology and pathology. Here a method for simultaneous imaging of CBF and spatially selective photoactivation of neural activity is proposed. CBF was obtained by laser speckle contrast imaging, and a liquid-crystal spatial light modulator (LC-SLM) was used to generate photoactivation patterns targeting designated locations in the cortex. Animal experiments stimulating defined cortical regions of VGAT-ChR2 and wild-type mice were conducted, and experiments with low-intensity stimulation were performed to investigate the influence of background light produced by the LC-SLM.
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