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Zimmerman CA, Bolkan SS, Pan-Vazquez A, Wu B, Keppler EF, Meares-Garcia JB, Guthman EM, Fetcho RN, McMannon B, Lee J, Hoag AT, Lynch LA, Janarthanan SR, López Luna JF, Bondy AG, Falkner AL, Wang SSH, Witten IB. A neural mechanism for learning from delayed postingestive feedback. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.06.561214. [PMID: 37873112 PMCID: PMC10592633 DOI: 10.1101/2023.10.06.561214] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Animals learn the value of foods based on their postingestive effects and thereby develop aversions to foods that are toxic1-6 and preferences to those that are nutritious7-14. However, it remains unclear how the brain is able to assign credit to flavors experienced during a meal with postingestive feedback signals that can arise after a substantial delay. Here, we reveal an unexpected role for postingestive reactivation of neural flavor representations in this temporal credit assignment process. To begin, we leverage the fact that mice learn to associate novel15-18, but not familiar, flavors with delayed gastric malaise signals to investigate how the brain represents flavors that support aversive postingestive learning. Surveying cellular resolution brainwide activation patterns reveals that a network of amygdala regions is unique in being preferentially activated by novel flavors across every stage of the learning process: the initial meal, delayed malaise, and memory retrieval. By combining high-density recordings in the amygdala with optogenetic stimulation of genetically defined hindbrain malaise cells, we find that postingestive malaise signals potently and specifically reactivate amygdalar novel flavor representations from a recent meal. The degree of malaise-driven reactivation of individual neurons predicts strengthening of flavor responses upon memory retrieval, leading to stabilization of the population-level representation of the recently consumed flavor. In contrast, meals without postingestive consequences degrade neural flavor representations as flavors become familiar and safe. Thus, our findings demonstrate that interoceptive reactivation of amygdalar flavor representations provides a neural mechanism to resolve the temporal credit assignment problem inherent to postingestive learning.
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Affiliation(s)
| | - Scott S Bolkan
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | | | - Bichan Wu
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Emma F Keppler
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | | | - Eartha Mae Guthman
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Robert N Fetcho
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Brenna McMannon
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Junuk Lee
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Austin T Hoag
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Laura A Lynch
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | | | - Juan F López Luna
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Adrian G Bondy
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Annegret L Falkner
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Samuel S-H Wang
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Ilana B Witten
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ, USA
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2
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Bielecki J, Dam Nielsen SK, Nachman G, Garm A. Associative learning in the box jellyfish Tripedalia cystophora. Curr Biol 2023; 33:4150-4159.e5. [PMID: 37741280 DOI: 10.1016/j.cub.2023.08.056] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 07/17/2023] [Accepted: 08/18/2023] [Indexed: 09/25/2023]
Abstract
Associative learning, such as classical or operant conditioning, has never been unequivocally associated with animals outside bilatarians, e.g., vertebrates, arthropods, or mollusks. Learning modulates behavior and is imperative for survival in the vast majority of animals. Obstacle avoidance is one of several visually guided behaviors in the box jellyfish, Tripedalia cystophora Conant, 1897 (Cnidaria: Cubozoa), and it is intimately associated with foraging between prop roots in their mangrove habitat. The obstacle avoidance behavior (OAB) is a species-specific defense reaction (SSDR) for T. cystophora, so identifying such SSDR is essential for testing the learning capacity of a given animal. Using the OAB, we show that box jellyfish performed associative learning (operant conditioning). We found that the rhopalial nervous system is the learning center and that T. cystophora combines visual and mechanical stimuli during operant conditioning. Since T. cystophora has a dispersed central nervous system lacking a conventional centralized brain, our work challenges the notion that associative learning requires complex neuronal circuitry. Moreover, since Cnidaria is the sister group to Bilateria, it suggests the intriguing possibility that advanced neuronal processes, like operant conditioning, are a fundamental property of all nervous systems.
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Affiliation(s)
- Jan Bielecki
- Institute of Physiology, Kiel University, 24118 Kiel, Germany.
| | | | - Gösta Nachman
- Section of Ecology and Evolution, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Anders Garm
- Marine Biological Section, University of Copenhagen, 2100 Copenhagen, Denmark.
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3
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Xu S, Momin M, Ahmed S, Hossain A, Veeramuthu L, Pandiyan A, Kuo CC, Zhou T. Illuminating the Brain: Advances and Perspectives in Optoelectronics for Neural Activity Monitoring and Modulation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303267. [PMID: 37726261 DOI: 10.1002/adma.202303267] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/30/2023] [Indexed: 09/21/2023]
Abstract
Optogenetic modulation of brain neural activity that combines optical and electrical modes in a unitary neural system has recently gained robust momentum. Controlling illumination spatial coverage, designing light-activated modulators, and developing wireless light delivery and data transmission are crucial for maximizing the use of optical neuromodulation. To this end, biocompatible electrodes with enhanced optoelectrical performance, device integration for multiplexed addressing, wireless transmission, and multimodal operation in soft systems have been developed. This review provides an outlook for uniformly illuminating large brain areas while spatiotemporally imaging the neural responses upon optoelectrical stimulation with little artifacts. Representative concepts and important breakthroughs, such as head-mounted illumination, multiple implanted optical fibers, and micro-light-delivery devices, are discussed. Examples of techniques that incorporate electrophysiological monitoring and optoelectrical stimulation are presented. Challenges and perspectives are posed for further research efforts toward high-density optoelectrical neural interface modulation, with the potential for nonpharmacological neurological disease treatments and wireless optoelectrical stimulation.
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Affiliation(s)
- Shumao Xu
- Department of Engineering Science and Mechanics, Center for Neural Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
| | - Marzia Momin
- Department of Engineering Science and Mechanics, Center for Neural Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
| | - Salahuddin Ahmed
- Department of Engineering Science and Mechanics, Center for Neural Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
| | - Arafat Hossain
- Department of Electrical Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
| | - Loganathan Veeramuthu
- Department of Molecular Science and Engineering, National Taipei University of Technology, Taipei, 10608, Republic of China
| | - Archana Pandiyan
- Department of Molecular Science and Engineering, National Taipei University of Technology, Taipei, 10608, Republic of China
| | - Chi-Ching Kuo
- Department of Molecular Science and Engineering, National Taipei University of Technology, Taipei, 10608, Republic of China
| | - Tao Zhou
- Department of Engineering Science and Mechanics, Center for Neural Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
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4
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Robins S. The 21st century engram. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2023; 14:e1653. [PMID: 37177850 DOI: 10.1002/wcs.1653] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/10/2023] [Accepted: 04/22/2023] [Indexed: 05/15/2023]
Abstract
The search for the engram-the neural mechanism of memory-has been a guiding research project for neuroscience since its emergence as a distinct scientific field. Recent developments in the tools and techniques available for investigating the mechanisms of memory have allowed researchers to proclaimed the search is over. While there is ongoing debate about the justification for that claim, renewed interest in the engram is clear. This attention highlights the impoverished status of the engram concept. As research accelerates, the simple characterization of the engram as an enduring physical change is stretched thin. Now that the engram commitment has been made more explicit, it must also be made more precise. If the project of 20th century neurobiology was finding the engram, the project of the 21st must be supplying a richer account of what's been found. This paper sketches a history of the engram, and a way forward. This article is categorized under: Philosophy > Foundations of Cognitive Science.
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Affiliation(s)
- Sarah Robins
- Department of Philosophy, University of Kansas, Lawrence, Kansas, USA
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Liu S, Wong HY, Xie L, Iqbal Z, Lei Z, Fu Z, Lam YY, Ramkrishnan AS, Li Y. Astrocytes in CA1 modulate schema establishment in the hippocampal-cortical neuron network. BMC Biol 2022; 20:250. [DOI: 10.1186/s12915-022-01445-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 10/20/2022] [Indexed: 11/11/2022] Open
Abstract
Abstract
Background
Schema, a concept from cognitive psychology used to explain how new information is integrated with previous experience, is a framework of acquired knowledge within associative network structures as biological correlate, which allows new relevant information to be quickly assimilated by parallel cortical encoding in the hippocampus (HPC) and cortex. Previous work demonstrated that myelin generation in the anterior cingulate cortex (ACC) plays a critical role for dynamic paired association (PA) learning and consolidation, while astrocytes in ACC play a vital role in cognitive decision-making. However, circuit components and mechanism involving HPC-anterior cingulate cortex (ACC) during schema formation remain uncertain. Moreover, the correlation between HPC-ACC circuit and HPC astrocytic activity is unclear.
Results
Utilizing a paired association (PA) behavioral paradigm, we dynamically recorded calcium signals of CA1-ACC projection neurons and ACC neurons during schema formation. Depending on the characteristics of the calcium signals, three distinct stages of schema establishment process were identified. The recruitment of CA1-ACC network was investigated in each stage under CA1 astrocytes Gi pathway chemogenetic activation. Results showed that CA1-ACC projecting neurons excitation gradually decreased along with schema development, while ACC neurons revealed an excitation peak in the middle stage. CA1 astrocytic Gi pathway activation will disrupt memory schema development by reducing CA1-ACC projection neuron recruitment in the initial stage and prevent both CA1-ACC projection neurons and ACC neuron excitation in the middle stage. CA1 astrocytes Gi markedly suppress new PA assimilation into the established memory schema.
Conclusions
These results not only reveal the dynamic feature of CA1-ACC network during schema establishment, but also suggest CA1 astrocyte contribution in different stages of schema establishment.
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Feasibility of Canine Adenovirus Type 2 (CAV2) Based Vector for the Locus Coeruleus Optogenetic Activation in Non-Transgenic Rats: Implications for Functional Studies. Brain Sci 2022; 12:brainsci12070904. [PMID: 35884711 PMCID: PMC9319986 DOI: 10.3390/brainsci12070904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/03/2022] [Accepted: 07/08/2022] [Indexed: 12/10/2022] Open
Abstract
The locus coeruleus norepinephrine (LC-NE) system modulates many visceral and cognitive functions, while LC-NE dysfunction leads to neurological and neurodegenerative conditions such as sleep disorders, depression, ADHD, or Alzheimer's disease. Innovative viral-vector and gene-engineering technology combined with the availability of cell-specific promoters enabled regional targeting and selective control over phenotypically specific populations of neurons. We transduced the LC-NE neurons in adult male rats by delivering the canine adenovirus type 2-based vector carrying the NE-specific promoter PRSx8 and a light-sensitive channelrhodopsin-2 receptor (ChR2) directly in the LC or retrogradely from the LC targets. The highest ChR2 expression level was achieved when the virus was delivered medially to the trigeminal pathway and ~100 μm lateral to the LC. The injections close or directly in the LC compromised the tissue integrity and NE cell phenotype. Retrograde labeling was more optimal given the transduction of projection-selective subpopulations. Our results highlight a limited inference of ChR2 expression from representative cases to the entire population of targeted cells. The actual fraction of manipulated neurons appears most essential for an adequate interpretation of the study outcome. The actual fraction of manipulated neurons appears most essential for an adequate interpretation of the study outcome. Thus, besides the cell-type specificity and the transduction efficiency, the between-subject variability in the proportion of the remaining viral-transduced targeted cell population must be considered in any functional connectivity study.
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Mirzayi P, Shobeiri P, Kalantari A, Perry G, Rezaei N. Optogenetics: implications for Alzheimer's disease research and therapy. Mol Brain 2022; 15:20. [PMID: 35197102 PMCID: PMC8867657 DOI: 10.1186/s13041-022-00905-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/10/2022] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD), a critical neurodegenerative condition, has a wide range of effects on brain activity. Synaptic plasticity and neuronal circuits are the most vulnerable in Alzheimer's disease, but the exact mechanism is unknown. Incorporating optogenetics into the study of AD has resulted in a significant leap in this field during the last decades, kicking off a revolution in our knowledge of the networks that underpin cognitive functions. In Alzheimer's disease, optogenetics can help to reduce and reverse neural circuit and memory impairments. Here we review how optogenetically driven methods have helped expand our knowledge of Alzheimer's disease, and how optogenetic interventions hint at a future translation into therapeutic possibilities for further utilization in clinical settings. In conclusion, neuroscience has witnessed one of its largest revolutions following the introduction of optogenetics into the field.
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Affiliation(s)
- Parsa Mirzayi
- School of Medicine, Tehran University of Medical Sciences (TUMS), Children's Medical Center Hospital, Dr. Qarib St., Keshavarz Blvd, 14194, Tehran, Iran
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Parnian Shobeiri
- School of Medicine, Tehran University of Medical Sciences (TUMS), Children's Medical Center Hospital, Dr. Qarib St., Keshavarz Blvd, 14194, Tehran, Iran
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
- Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Amirali Kalantari
- School of Medicine, Tehran University of Medical Sciences (TUMS), Children's Medical Center Hospital, Dr. Qarib St., Keshavarz Blvd, 14194, Tehran, Iran
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - George Perry
- Department of Biology and Neurosciences Institute, University of Texas at San Antonio (UTSA), San Antonio, TX, USA
| | - Nima Rezaei
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
- Research Center for Immunodeficiencies, Children's Medical Center, Dr. Gharib St, Keshavarz Blvd, Tehran, Iran.
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8
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Keshmiri Neghab H, Soheilifar MH, Grusch M, Ortega MM, Esmaeeli Djavid G, Saboury AA, Goliaei B. The state of the art of biomedical applications of optogenetics. Lasers Surg Med 2021; 54:202-216. [PMID: 34363230 DOI: 10.1002/lsm.23463] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 07/08/2021] [Accepted: 07/23/2021] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND OBJECTIVE Optogenetics has opened new insights into biomedical research with the ability to manipulate and control cellular activity using light in combination with genetically engineered photosensitive proteins. By stimulating with light, this method provides high spatiotemporal and high specificity resolution, which is in contrast to conventional pharmacological or electrical stimulation. Optogenetics was initially introduced to control neural activities but was gradually extended to other biomedical fields. STUDY DESIGN In this paper, firstly, we summarize the current optogenetic tools stimulated by different light sources, including lasers, light-emitting diodes, and laser diodes. Second, we outline the variety of biomedical applications of optogenetics not only for neuronal circuits but also for various kinds of cells and tissues from cardiomyocytes to ganglion cells. Furthermore, we highlight the potential of this technique for treating neurological disorders, cardiac arrhythmia, visual impairment, hearing loss, and urinary bladder diseases as well as clarify the mechanisms underlying cancer progression and control of stem cell differentiation. CONCLUSION We sought to summarize the various types of promising applications of optogenetics to treat a broad spectrum of disorders. It is conceivable to expect that optogenetics profits a growing number of patients suffering from a range of different diseases in the near future.
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Affiliation(s)
- Hoda Keshmiri Neghab
- Department of Photo Healing and Regeneration, Medical Laser Research Center, Yara Institute, ACECR, Tehran, Iran
| | | | - Michael Grusch
- Department of Medicine I, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Manoela Marques Ortega
- Laboratory of Cell and Molecular Tumor Biology and Bioactive Compounds, São Francisco University, Bragança Paulista, São Paulo, Brazil
| | - Gholamreza Esmaeeli Djavid
- Department of Photo Healing and Regeneration, Medical Laser Research Center, Yara Institute, ACECR, Tehran, Iran
| | - Ali Akbar Saboury
- Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Bahram Goliaei
- Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
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9
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Honoré E, Khlaifia A, Bosson A, Lacaille JC. Hippocampal Somatostatin Interneurons, Long-Term Synaptic Plasticity and Memory. Front Neural Circuits 2021; 15:687558. [PMID: 34149368 PMCID: PMC8206813 DOI: 10.3389/fncir.2021.687558] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 04/30/2021] [Indexed: 12/13/2022] Open
Abstract
A distinctive feature of the hippocampal structure is the diversity of inhibitory interneurons. These complex inhibitory interconnections largely contribute to the tight modulation of hippocampal circuitry, as well as to the formation and coordination of neuronal assemblies underlying learning and memory. Inhibitory interneurons provide more than a simple transitory inhibition of hippocampal principal cells (PCs). The synaptic plasticity of inhibitory neurons provides long-lasting changes in the hippocampal network and is a key component of memory formation. The dendrite targeting interneurons expressing the peptide somatostatin (SOM) are particularly interesting in this regard because they display unique long-lasting synaptic changes leading to metaplastic regulation of hippocampal networks. In this article, we examine the actions of the neuropeptide SOM on hippocampal cells, synaptic plasticity, learning, and memory. We address the different subtypes of hippocampal SOM interneurons. We describe the long-term synaptic plasticity that takes place at the excitatory synapses of SOM interneurons, its singular induction and expression mechanisms, as well as the consequences of these changes on the hippocampal network, learning, and memory. We also review evidence that astrocytes provide cell-specific dynamic regulation of inhibition of PC dendrites by SOM interneurons. Finally, we cover how, in mouse models of Alzheimer’s disease (AD), dysfunction of plasticity of SOM interneuron excitatory synapses may also contribute to cognitive impairments in brain disorders.
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Affiliation(s)
- Eve Honoré
- Department of Neurosciences, Centre for Interdisciplinary Research on Brain and Learning, Research Group on the Central Nervous System, Université de Montréal, Montreal, QC, Canada
| | - Abdessattar Khlaifia
- Department of Neurosciences, Centre for Interdisciplinary Research on Brain and Learning, Research Group on the Central Nervous System, Université de Montréal, Montreal, QC, Canada
| | - Anthony Bosson
- Department of Neurosciences, Centre for Interdisciplinary Research on Brain and Learning, Research Group on the Central Nervous System, Université de Montréal, Montreal, QC, Canada
| | - Jean-Claude Lacaille
- Department of Neurosciences, Centre for Interdisciplinary Research on Brain and Learning, Research Group on the Central Nervous System, Université de Montréal, Montreal, QC, Canada
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Hemonnot-Girard AL, Ben Haim L, Escartin C, Hirbec H. [New technologies to unveil the role of brain glial cells]. Med Sci (Paris) 2021; 37:59-67. [PMID: 33492220 DOI: 10.1051/medsci/2020253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Brain function relies on complex interactions between neurons and different types of glial cells, such as astrocytes, microglia and oligodendrocytes. The relatively young field of "gliobiology" is thriving. Thanks to various technical innovations, it is now possible to address challenging biological questions on glial cells and unravel their multiple roles in brain function and dysfunction.
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Affiliation(s)
| | - Lucile Ben Haim
- Université Paris-Saclay, CEA, CNRS, MIRCen (Molecular Imaging Research Center), Laboratoire des maladies neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Carole Escartin
- Université Paris-Saclay, CEA, CNRS, MIRCen (Molecular Imaging Research Center), Laboratoire des maladies neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Hélène Hirbec
- IGF, Univ Montpellier, CNRS, Inserm, Montpellier, France
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11
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Kol A, Adamsky A, Groysman M, Kreisel T, London M, Goshen I. Astrocytes contribute to remote memory formation by modulating hippocampal-cortical communication during learning. Nat Neurosci 2020; 23:1229-1239. [PMID: 32747787 PMCID: PMC7611962 DOI: 10.1038/s41593-020-0679-6] [Citation(s) in RCA: 185] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 06/26/2020] [Indexed: 12/15/2022]
Abstract
Remote memories depend on coordinated activity in the hippocampus and frontal cortices, but the timeline of these interactions is debated. Astrocytes sense and modify neuronal activity, but their role in remote memory was scarcely explored. We expressed the Gi-coupled receptor hM4Di in CA1 astrocytes, and discovered that astrocytic manipulation during learning specifically impaired remote, but not recent, memory recall, and decreased activity in the anterior cingulate cortex (ACC) during retrieval. We revealed massive recruitment of ACC-projecting CA1 neurons during memory acquisition, accompanied by activation of ACC neurons. Astrocytic Gi activation disrupted CA3 to CA1 communication in-vivo, and reduced the downstream response in ACC. In behaving mice, it induced a projection-specific inhibition of CA1-to-ACC neurons during learning, consequently preventing ACC recruitment. Finally, direct inhibition of CA1-to-ACC projecting neurons spared recent and impaired remote memory. Our findings suggest that remote memory acquisition involves projection-specific functions of astrocytes in regulating CA1-to-ACC neuronal communication.
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Affiliation(s)
- Adi Kol
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Adar Adamsky
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Maya Groysman
- ELSC Vector Core Facility, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tirzah Kreisel
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Michael London
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel.,Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Inbal Goshen
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel.
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12
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Hirbec H, Déglon N, Foo LC, Goshen I, Grutzendler J, Hangen E, Kreisel T, Linck N, Muffat J, Regio S, Rion S, Escartin C. Emerging technologies to study glial cells. Glia 2020; 68:1692-1728. [PMID: 31958188 DOI: 10.1002/glia.23780] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 12/11/2022]
Abstract
Development, physiological functions, and pathologies of the brain depend on tight interactions between neurons and different types of glial cells, such as astrocytes, microglia, oligodendrocytes, and oligodendrocyte precursor cells. Assessing the relative contribution of different glial cell types is required for the full understanding of brain function and dysfunction. Over the recent years, several technological breakthroughs were achieved, allowing "glio-scientists" to address new challenging biological questions. These technical developments make it possible to study the roles of specific cell types with medium or high-content workflows and perform fine analysis of their mutual interactions in a preserved environment. This review illustrates the potency of several cutting-edge experimental approaches (advanced cell cultures, induced pluripotent stem cell (iPSC)-derived human glial cells, viral vectors, in situ glia imaging, opto- and chemogenetic approaches, and high-content molecular analysis) to unravel the role of glial cells in specific brain functions or diseases. It also illustrates the translation of some techniques to the clinics, to monitor glial cells in patients, through specific brain imaging methods. The advantages, pitfalls, and future developments are discussed for each technique, and selected examples are provided to illustrate how specific "gliobiological" questions can now be tackled.
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Affiliation(s)
- Hélène Hirbec
- Institute for Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Nicole Déglon
- Laboratory of Neurotherapies and Neuromodulation, Department of Clinical Neuroscience, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland.,Laboratory of Neurotherapies and Neuromodulation, Neuroscience Research Center, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Lynette C Foo
- Neuroimmunology and Neurodegeneration Section, The Neuroscience and Rare Diseases Discovery and Translational Area, F. Hoffman-La Roche, Basel, Switzerland
| | - Inbal Goshen
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jaime Grutzendler
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Emilie Hangen
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département de la Recherche Fondamentale, Institut de Biologie François Jacob, MIRCen, Fontenay-aux-Roses, France.,Centre National de la Recherche Scientifique, Neurodegenerative Diseases Laboratory, Université Paris-Sud, Université Paris-Saclay, UMR 9199, Fontenay-aux-Roses, France
| | - Tirzah Kreisel
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nathalie Linck
- Institute for Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Julien Muffat
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, and Department of Molecular Genetics, The University of Toronto, Toronto, Canada
| | - Sara Regio
- Laboratory of Neurotherapies and Neuromodulation, Department of Clinical Neuroscience, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland.,Laboratory of Neurotherapies and Neuromodulation, Neuroscience Research Center, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Sybille Rion
- Neuroimmunology and Neurodegeneration Section, The Neuroscience and Rare Diseases Discovery and Translational Area, F. Hoffman-La Roche, Basel, Switzerland
| | - Carole Escartin
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département de la Recherche Fondamentale, Institut de Biologie François Jacob, MIRCen, Fontenay-aux-Roses, France.,Centre National de la Recherche Scientifique, Neurodegenerative Diseases Laboratory, Université Paris-Sud, Université Paris-Saclay, UMR 9199, Fontenay-aux-Roses, France
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13
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The striatum, the hippocampus, and short-term memory binding: Volumetric analysis of the subcortical grey matter's role in mild cognitive impairment. NEUROIMAGE-CLINICAL 2019; 25:102158. [PMID: 31918064 PMCID: PMC7036699 DOI: 10.1016/j.nicl.2019.102158] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/27/2019] [Accepted: 12/28/2019] [Indexed: 12/14/2022]
Abstract
Hippocampal atrophy plays no role in short-term memory binding. The globus pallidus could be part of the brain network supporting binding. Total brain atrophy does not correlate with striatal grey matter atrophy in MCI. Striatal grey matter atrophy reflects in total brain atrophy in controls. Hippocampal and parahippocampal volumes correlate in MCI and controls.
Background Deficits in short-term memory (STM) binding are a distinguishing feature of preclinical stages leading to Alzheimer's disease (AD). However, the neuroanatomical correlates of conjunctive STM binding are largely unexplored. Here we examine the possible association between the volumes of hippocampi, parahippocampal gyri, and grey matter within the subcortical structures – all found to have foci that seemingly correlate with basic daily living activities in AD patients - with cognitive tests related to conjunctive STM binding. Materials and methods Hippocampal, thalamic, parahippocampal and corpus striatum volumes were semi-automatically quantified in brain magnetic resonance images from 25 cognitively normal people and 21 patients with Mild Cognitive Impairment (MCI) at high risk of AD progression, who undertook a battery of cognitive tests and the short-term memory binding test. Associations were assessed using linear regression models and group differences were assessed using the Mann-Whitney U test. Results Hippocampal and parahippocampal gyrus volumes differed between MCI and control groups. Although the grey matter volume in the globus pallidus (r = -0.71, p < 0.001) and parahippocampal gyry (r = -0.63, p < 0.05) correlated with a STM binding task in the MCI group, only the former remained associated with STM binding deficits in MCI patients, after correcting for age, gender and years of education (β = -0.56,P = 0.042) although with borderline significance. Conclusions Loss of hippocampal volume plays no role in the processing of STM binding. Structures within the basal ganglia, namely the globus pallidus, could be part of the extrahippocampal network supporting binding. Replication of this study in large samples is now needed.
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14
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Bickle J. Laser Lights and Designer Drugs: New Techniques for Descending Levels of Mechanisms “in a Single Bound”? Top Cogn Sci 2019; 12:1241-1256. [DOI: 10.1111/tops.12452] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 07/26/2019] [Accepted: 07/30/2019] [Indexed: 12/01/2022]
Affiliation(s)
- John Bickle
- Mississippi State Univesity
- University of Mississippi Medical Center
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15
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Quillfeldt JA. Temporal Flexibility of Systems Consolidation and the Synaptic Occupancy/Reset Theory (SORT): Cues About the Nature of the Engram. Front Synaptic Neurosci 2019; 11:1. [PMID: 30814946 PMCID: PMC6381034 DOI: 10.3389/fnsyn.2019.00001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 01/14/2019] [Indexed: 11/24/2022] Open
Abstract
The ability to adapt to new situations involves behavioral changes expressed either from an innate repertoire, or by acquiring experience through memory consolidation mechanisms, by far a much richer and flexible source of adaptation. Memory formation consists of two interrelated processes that take place at different spatial and temporal scales, Synaptic Consolidation, local plastic changes in the recruited neurons, and Systems Consolidation, a process of gradual reorganization of the explicit/declarative memory trace between hippocampus and the neocortex. In this review, we summarize some converging experimental results from our lab that support a normal temporal framework of memory systems consolidation as measured both from the anatomical and the psychological points of view, and propose a hypothetical model that explains these findings while predicting other phenomena. Then, the same experimental design was repeated interposing additional tasks between the training and the remote test to verify for any interference: we found that (a) when the animals were subject to a succession of new learnings, systems consolidation was accelerated, with the disengagement of the hippocampus taking place before the natural time point of this functional switch, but (b) when a few reactivation sessions reexposed the animal to the training context without the shock, systems consolidation was delayed, with the hippocampus prolonging its involvement in retrieval. We hypothesize that new learning recruits from a fixed number of plastic synapses in the CA1 area to store the engram index, while reconsolidation lead to a different outcome, in which additional synapses are made available. The first situation implies the need of a reset mechanism in order to free synapses needed for further learning, and explains the acceleration observed under intense learning activity, while the delay might be explained by a different process, able to generate extra free synapses: depending on the cognitive demands, it deals either with a fixed or a variable pool of available synapses. The Synaptic Occupancy/Reset Theory (SORT) emerged as an explanation for the temporal flexibility of systems consolidation, to encompass the two different dynamics of explicit memories, as well as to bridge both synaptic and systems consolidation in one single mechanism.
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Affiliation(s)
- Jorge Alberto Quillfeldt
- Psychobiology and Neurocomputation Lab, Department of Biophysics, Institute of Biosciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Department of Psychology, McGill University, Montreal, QC, Canada
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16
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Luchkina NV, Bolshakov VY. Diminishing fear: Optogenetic approach toward understanding neural circuits of fear control. Pharmacol Biochem Behav 2018; 174:64-79. [PMID: 28502746 PMCID: PMC5681900 DOI: 10.1016/j.pbb.2017.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 04/13/2017] [Accepted: 05/10/2017] [Indexed: 02/05/2023]
Abstract
Understanding complex behavioral processes, both learned and innate, requires detailed characterization of the principles governing signal flow in corresponding neural circuits. Previous studies were hampered by the lack of appropriate tools needed to address the complexities of behavior-driving micro- and macrocircuits. The development and implementation of optogenetic methodologies revolutionized the field of behavioral neuroscience, allowing precise spatiotemporal control of specific, genetically defined neuronal populations and their functional connectivity both in vivo and ex vivo, thus providing unprecedented insights into the cellular and network-level mechanisms contributing to behavior. Here, we review recent pioneering advances in behavioral studies with optogenetic tools, focusing on mechanisms of fear-related behavioral processes with an emphasis on approaches which could be used to suppress fear when it is pathologically expressed. We also discuss limitations of these methodologies as well as review new technological developments which could be used in future mechanistic studies of fear behavior.
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Affiliation(s)
- Natalia V Luchkina
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA.
| | - Vadim Y Bolshakov
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA.
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17
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Doron A, Goshen I. Investigating the transition from recent to remote memory using advanced tools. Brain Res Bull 2018; 141:35-43. [DOI: 10.1016/j.brainresbull.2017.09.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 08/27/2017] [Accepted: 09/11/2017] [Indexed: 11/30/2022]
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18
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Astrocytic Activation Generates De Novo Neuronal Potentiation and Memory Enhancement. Cell 2018; 174:59-71.e14. [PMID: 29804835 DOI: 10.1016/j.cell.2018.05.002] [Citation(s) in RCA: 394] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 01/31/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022]
Abstract
Astrocytes respond to neuronal activity and were shown to be necessary for plasticity and memory. To test whether astrocytic activity is also sufficient to generate synaptic potentiation and enhance memory, we expressed the Gq-coupled receptor hM3Dq in CA1 astrocytes, allowing their activation by a designer drug. We discovered that astrocytic activation is not only necessary for synaptic plasticity, but also sufficient to induce NMDA-dependent de novo long-term potentiation in the hippocampus that persisted after astrocytic activation ceased. In vivo, astrocytic activation enhanced memory allocation; i.e., it increased neuronal activity in a task-specific way only when coupled with learning, but not in home-caged mice. Furthermore, astrocytic activation using either a chemogenetic or an optogenetic tool during acquisition resulted in memory recall enhancement on the following day. Conversely, directly increasing neuronal activity resulted in dramatic memory impairment. Our findings that astrocytes induce plasticity and enhance memory may have important clinical implications for cognitive augmentation treatments.
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19
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Miyamoto H, Shimohata A, Abe M, Abe T, Mazaki E, Amano K, Suzuki T, Tatsukawa T, Itohara S, Sakimura K, Yamakawa K. Potentiation of excitatory synaptic transmission ameliorates aggression in mice with Stxbp1 haploinsufficiency. Hum Mol Genet 2017; 26:4961-4974. [DOI: 10.1093/hmg/ddx379] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/09/2017] [Indexed: 11/13/2022] Open
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20
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Adamsky A, Goshen I. Astrocytes in Memory Function: Pioneering Findings and Future Directions. Neuroscience 2017; 370:14-26. [PMID: 28571720 DOI: 10.1016/j.neuroscience.2017.05.033] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/05/2017] [Accepted: 05/19/2017] [Indexed: 12/29/2022]
Abstract
Astrocytes have been generally believed to perform mainly homeostatic and supportive functions for neurons in the central nervous system. Recently, a growing body of evidence suggests previously unrecognized and surprising functions for astrocytes, including regulation of synaptic formation, transmission and plasticity, all of which are considered as the infrastructure for information processing and memory formation and stabilization. This review discusses the involvement of astrocytes in memory functions and the possible mechanisms that may underlie it. We review the important breakthroughs obtained in this field, as well as some of the controversies that arose from the past difficulty to manipulate these cells in a cell type-specific and non-invasive manner. Finally, we present new research avenues based on the advanced tools becoming available in recent years: optogenetics and chemogenetics, and the potential ways in which these tools may further illuminate the role of astrocytes in memory processes.
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Affiliation(s)
- Adar Adamsky
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Givat Ram, Jerusalem 91904, Israel
| | - Inbal Goshen
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Givat Ram, Jerusalem 91904, Israel.
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21
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Yang Q, Song D, Qing H. Neural changes in Alzheimer's disease from circuit to molecule: Perspective of optogenetics. Neurosci Biobehav Rev 2017; 79:110-118. [PMID: 28522119 DOI: 10.1016/j.neubiorev.2017.05.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/21/2017] [Accepted: 05/12/2017] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD), as a crucial neurodegenerative disorder, affects neural activities at many levels. Synaptic plasticity and neural circuits are most susceptible in AD, but the detailed mechanism is unclear. Optogenetic tools provide unprecedented spatio-temporal specificity to stimulate specific neural circuits or synaptic molecules to reveal the precise function of normal brain and mechanism of deficits in AD models. Furthermore, using optogenetics to stimulate neurons can rescue learning and memory loss caused by AD. It also has possibility to use light to control the Neurotransmitter receptors and their downstream signal pathway. These technical methods have broad therapeutic application prospect.
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Affiliation(s)
- Qinghu Yang
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Da Song
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Hong Qing
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China.
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22
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Owens MT, Tanner KD. Teaching as Brain Changing: Exploring Connections between Neuroscience and Innovative Teaching. CBE LIFE SCIENCES EDUCATION 2017; 16:16/2/fe2. [PMID: 28450442 PMCID: PMC5459260 DOI: 10.1187/cbe.17-01-0005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
One would hope that of the many ways to conceptualize teaching and learning, scientists would view these processes as driving biological changes in the brain. Here, the authors draw connections between innovative teaching techniques and neuroscience that may support our understanding of why innovative teaching is so effective at promoting learning.
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Affiliation(s)
- Melinda T Owens
- Science Education Partnership and Assessment Laboratory, San Francisco State University, San Francisco, CA 94132
| | - Kimberly D Tanner
- Science Education Partnership and Assessment Laboratory, San Francisco State University, San Francisco, CA 94132
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23
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Towne C, Thompson KR. Overview on Research and Clinical Applications of Optogenetics. ACTA ACUST UNITED AC 2016; 75:11.19.1-11.19.21. [DOI: 10.1002/cpph.13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Chris Towne
- Circuit Therapeutics, Inc Menlo Park California
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24
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Govorunova EG, Koppel LA. The Road to Optogenetics: Microbial Rhodopsins. BIOCHEMISTRY (MOSCOW) 2016; 81:928-40. [PMID: 27682165 DOI: 10.1134/s0006297916090029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Optogenetics technology (using light-sensitive microbial proteins to control animal cell physiology) is becoming increasingly popular in laboratories around the world. Among these proteins, particularly important are rhodopsins that transport ions across the membrane and are used in optogenetics to regulate membrane potential by light, mostly in neurons. Although rhodopsin ion pumps transport only one charge per captured photon, channelrhodopsins are capable of more efficient passive transport. In this review, we follow the history of channelrhodopsin discovery in flagellate algae and discuss the latest addition to the channelrhodopsin family, channels with anion, rather than cation, selectivity.
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Affiliation(s)
- E G Govorunova
- Lomonosov Moscow State University, School of Biology, Moscow, 119991, Russia.
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25
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Bergstrom HC. The neurocircuitry of remote cued fear memory. Neurosci Biobehav Rev 2016; 71:409-417. [PMID: 27693699 DOI: 10.1016/j.neubiorev.2016.09.028] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 09/25/2016] [Accepted: 09/27/2016] [Indexed: 11/16/2022]
Abstract
Memories of threatening, fear-evoking events can persist even over a lifetime. While fear memory is widely considered to be a highly persistent and durable form of memory, its circuits are not. This article reviews the dynamic temporal representation of remote fear memory in the brain, at the level of local circuits and distributed networks. Data from the study of Pavlovian cued fear conditioning suggests memory retrieval remains amygdala-dependent, even over protracted time scales, all the while interconnected cortical and subcortical circuits are newly recruited and progressively reorganized. A deeper understanding into how the neurocircuitry of cued fear memory reorganizes with the passage of time will advance our ongoing search for the elusive physical changes representing fear memories in the brain. Considering that persistent, pathological fear memories are a hallmark feature of post-traumatic stress disorder (PTSD), the behavioral and circuit-level study of remote cued fear memory retrieval adds a key element towards a systems understanding of PTSD.
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Affiliation(s)
- Hadley C Bergstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY 12604, United States.
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26
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Grimaud J, Lledo PM. Illuminating odors: when optogenetics brings to light unexpected olfactory abilities. ACTA ACUST UNITED AC 2016; 23:249-54. [PMID: 27194792 PMCID: PMC4880145 DOI: 10.1101/lm.041269.115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/17/2016] [Indexed: 11/25/2022]
Abstract
For hundreds of years, the sense of smell has generated great interest in the world literature, oenologists, and perfume makers but less of scientists. Only recently this sensory modality has gained new attraction in neuroscience when original tools issued from physiology, anatomy, or molecular biology were available to decipher how the brain makes sense of olfactory cues. However, this move was promptly dampened by the difficulties of developing quantitative approaches to study the relationship between the physical characteristics of stimuli and the sensations they create. An upswing of olfactory investigations occurred when genetic tools could be used in combination with devices borrowed from the physics of light (a hybrid technique called optogenetics) to scrutinize the olfactory system and to provide greater physiological precision for studying olfactory-driven behaviors. This review aims to present the most recent studies that have used light to activate components of the olfactory pathway, such as olfactory receptor neurons, or neurons located further downstream, while leaving intact others brain circuits. With the use of optogenetics to unravel the mystery of olfaction, scientists have begun to disentangle how the brain makes sense of smells. In this review, we shall discuss how the brain recognizes odors, how it memorizes them, and how animals make decisions based on odorants they are capable of sensing. Although this review deals with olfaction, the role of light will be central throughout.
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Affiliation(s)
- Julien Grimaud
- Institut Pasteur, Laboratory for Perception and Memory, F-75015 Paris, France Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 3571, F-75015 Paris, France
| | - Pierre-Marie Lledo
- Institut Pasteur, Laboratory for Perception and Memory, F-75015 Paris, France Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 3571, F-75015 Paris, France
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27
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Bickle J. Revolutions in Neuroscience: Tool Development. Front Syst Neurosci 2016; 10:24. [PMID: 27013992 PMCID: PMC4782158 DOI: 10.3389/fnsys.2016.00024] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/22/2016] [Indexed: 11/13/2022] Open
Abstract
Thomas Kuhn's famous model of the components and dynamics of scientific revolutions is still dominant to this day across science, philosophy, and history. The guiding philosophical theme of this article is that, concerning actual revolutions in neuroscience over the past 60 years, Kuhn's account is wrong. There have been revolutions, and new ones are brewing, but they do not turn on competing paradigms, anomalies, or the like. Instead, they turn exclusively on the development of new experimental tools. I adopt a metascientific approach and examine in detail the development of two recent neuroscience revolutions: the impact of engineered genetically mutated mammals in the search for causal mechanisms of "higher" cognitive functions; and the more recent impact of optogenetics and designer receptors exclusively activated by designer drugs (DREADDs). The two key metascientific concepts, I derive from these case studies are a revolutionary new tool's motivating problem, and its initial and second-phase hook experiments. These concepts hardly exhaust a detailed metascience of tool development experiments in neuroscience, but they get that project off to a useful start and distinguish the subsequent account of neuroscience revolutions clearly from Kuhn's famous model. I close with a brief remark about the general importance of molecular biology for a current philosophical understanding of science, as comparable to the place physics occupied when Kuhn formulated his famous theory of scientific revolutions.
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Affiliation(s)
- John Bickle
- Department of Philosophy and Religion, Mississippi State UniversityMississippi, MS, USA; Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical CenterJackson, MS, USA
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28
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Adult Hippocampal Neurogenesis, Fear Generalization, and Stress. Neuropsychopharmacology 2016; 41:24-44. [PMID: 26068726 PMCID: PMC4677119 DOI: 10.1038/npp.2015.167] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 05/29/2015] [Accepted: 06/05/2015] [Indexed: 12/21/2022]
Abstract
The generalization of fear is an adaptive, behavioral, and physiological response to the likelihood of threat in the environment. In contrast, the overgeneralization of fear, a cardinal feature of posttraumatic stress disorder (PTSD), manifests as inappropriate, uncontrollable expression of fear in neutral and safe environments. Overgeneralization of fear stems from impaired discrimination of safe from aversive environments or discernment of unlikely threats from those that are highly probable. In addition, the time-dependent erosion of episodic details of traumatic memories might contribute to their generalization. Understanding the neural mechanisms underlying the overgeneralization of fear will guide development of novel therapeutic strategies to combat PTSD. Here, we conceptualize generalization of fear in terms of resolution of interference between similar memories. We propose a role for a fundamental encoding mechanism, pattern separation, in the dentate gyrus (DG)-CA3 circuit in resolving interference between ambiguous or uncertain threats and in preserving episodic content of remote aversive memories in hippocampal-cortical networks. We invoke cellular-, circuit-, and systems-based mechanisms by which adult-born dentate granule cells (DGCs) modulate pattern separation to influence resolution of interference and maintain precision of remote aversive memories. We discuss evidence for how these mechanisms are affected by stress, a risk factor for PTSD, to increase memory interference and decrease precision. Using this scaffold we ideate strategies to curb overgeneralization of fear in PTSD.
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29
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Sweeney P, Yang Y. An excitatory ventral hippocampus to lateral septum circuit that suppresses feeding. Nat Commun 2015; 6:10188. [PMID: 26666960 PMCID: PMC4682174 DOI: 10.1038/ncomms10188] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 11/12/2015] [Indexed: 12/20/2022] Open
Abstract
Previous research has focused on feeding circuits residing in the hindbrain and midbrain that govern homeostatic or hedonic control of food intake. However, the feeding circuits controlling emotional or cognitive aspects of food intake are largely unknown. Here we use chemical genetics and optogenetic techniques to dissect appetite control circuits originating from ventral hippocampus (vHPC), a brain region implicated in emotion and cognition. We find that the vHPC projects functional glutamatergic synaptic inputs to the lateral septum (LS) and optogenetic activation of vHPC projections in LS reduces food intake. Consistently, food intake is suppressed by chemogenetic activation of glutamatergic neurons in the vHPC that project to the LS and inactivation of LS neurons blunts vHPC-induced suppression of feeding. Collectively, our results identify an anorexigenic neural circuit originating from vHPC to LS in the brain, revealing a potential therapeutic target for the treatment of anorexia or other appetite disorders. The ventral hippocampus connects to the hypothalamus and has been implicated in feeding behaviours. Here, the authors use a combination of optogenetics and DREADD strategies to dissect the underlying circuit, showing that projections from the vHC to the lateral septum work to regulate feeding suppression.
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Affiliation(s)
- Patrick Sweeney
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, 505 Irving Avenue, IHP#3609, Syracuse, New York 13210, USA
| | - Yunlei Yang
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, 505 Irving Avenue, IHP#3609, Syracuse, New York 13210, USA
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30
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Bunzeck N, Thiel C. Neurochemical modulation of repetition suppression and novelty signals in the human brain. Cortex 2015; 80:161-73. [PMID: 26625882 DOI: 10.1016/j.cortex.2015.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/22/2015] [Accepted: 10/15/2015] [Indexed: 12/11/2022]
Abstract
The repeated processing of a sensory stimulus, such as a picture or sound, leads to a decrement in response in neurons that fired to the initial presentation. These effects are well known from single cell recordings in the inferior temporal cortex in monkeys, and functional neuroimaging in humans on large-scale neural activity could show similar effects in extrastriate, frontal and medial temporal lobe (MTL) regions. The role of specific neurotransmitters in repeated processing of information is, however, less clear. In the first part of this article, we will introduce the two concepts of repetition suppression and novelty signals, which is followed by a brief overview of pharmacological neuroimaging in humans. We will then summarize human studies suggesting that gamma-aminobutyric-acid (GABA) and acetylcholine (ACh) play an important role in modulating behavioral priming and associated repetition suppression in extrastriate and frontal brain regions. Finally, we review studies on neural novelty signals in the dopaminergic mesolimbic system, and conclude that dopamine (DA) regulates the temporal aspects of novelty processing and closely relates to long-term memory encoding rather than behavioral priming. As such, this review describes differential roles of GABA, ACh and DA in repeated stimulus processing, and further suggests that repetition suppression and neural novelty signals may not be two sides of the same coin but rather independent processes.
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Affiliation(s)
- Nico Bunzeck
- Department of Psychology, University of Lübeck, Lübeck, Germany; Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Christiane Thiel
- Biological Psychology, Department of Psychology, European Medical School, Carl von Ossietzky University Oldenburg, Oldenburg, Germany; Cluster of Excellence "Hearing4all" and Research Center Neurosensory Science, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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Kim EGR, Tu H, Luo H, Liu B, Bao S, Zhang J, Xu Y. 3D silicon neural probe with integrated optical fibers for optogenetic modulation. LAB ON A CHIP 2015; 15:2939-2949. [PMID: 26097907 DOI: 10.1039/c4lc01472c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Optogenetics is a powerful modality for neural modulation that can be useful for a wide array of biomedical studies. Penetrating microelectrode arrays provide a means of recording neural signals with high spatial resolution. It is highly desirable to integrate optics with neural probes to allow for functional study of neural tissue by optogenetics. In this paper, we report the development of a novel 3D neural probe coupled simply and robustly to optical fibers using a hollow parylene tube structure. The device shanks are hollow tubes with rigid silicon tips, allowing the insertion and encasement of optical fibers within the shanks. The position of the fiber tip can be precisely controlled relative to the electrodes on the shank by inherent design features. Preliminary in vivo rat studies indicate that these devices are capable of optogenetic modulation simultaneously with 3D neural signal recording.
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Affiliation(s)
- Eric G R Kim
- The Biomedical Engineering Department of Wayne State University, Detroit, MI 48202, USA.
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