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Caccavano AP, Kimmel S, Vlachos A, Mahadevan V, Kim JH, Vargish G, Chittajallu R, London E, Yuan X, Hunt S, Eldridge MAG, Cummins AC, Hines BE, Plotnikova A, Mohanty A, Averbeck BB, Zaghloul K, Dimidschstein J, Fishell G, Pelkey KA, McBain CJ. Divergent opioid-mediated suppression of inhibition between hippocampus and neocortex across species and development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.20.576455. [PMID: 38313283 PMCID: PMC10836073 DOI: 10.1101/2024.01.20.576455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Opioid receptors within the CNS regulate pain sensation and mood and are key targets for drugs of abuse. Within the adult rodent hippocampus (HPC), μ-opioid receptor agonists suppress inhibitory parvalbumin-expressing interneurons (PV-INs), thus disinhibiting the circuit. However, it is uncertain if this disinhibitory motif is conserved in other cortical regions, species, or across development. We observed that PV-IN mediated inhibition is robustly suppressed by opioids in HPC but not neocortex in mice and nonhuman primates, with spontaneous inhibitory tone in resected human tissue also following a consistent dichotomy. This hippocampal disinhibitory motif was established in early development when immature PV-INs and opioids already influence primordial network rhythmogenesis. Acute opioid-mediated modulation was partially occluded with morphine pretreatment, with implications for the effects of opioids on hippocampal network activity during circuit maturation as well as learning and memory. Together, these findings demonstrate that PV-INs exhibit a divergence in opioid sensitivity across brain regions that is remarkably conserved across evolution and highlights the underappreciated role of opioids acting through immature PV-INs in shaping hippocampal development.
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Affiliation(s)
- Adam P Caccavano
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Sarah Kimmel
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Anna Vlachos
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Vivek Mahadevan
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - June Hoan Kim
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Geoffrey Vargish
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Ramesh Chittajallu
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Edra London
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Xiaoqing Yuan
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Steven Hunt
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | | | - Alex C Cummins
- National Institute of Mental Health (NIMH), NIH, Bethesda, MD, USA
| | - Brendan E Hines
- National Institute of Mental Health (NIMH), NIH, Bethesda, MD, USA
| | - Anya Plotnikova
- National Institute of Mental Health (NIMH), NIH, Bethesda, MD, USA
| | - Arya Mohanty
- National Institute of Mental Health (NIMH), NIH, Bethesda, MD, USA
| | - Bruno B Averbeck
- National Institute of Mental Health (NIMH), NIH, Bethesda, MD, USA
| | - Kareem Zaghloul
- National Institute of Neurological Disorders and Stroke (NINDS) Intramural Research Program, NIH Bethesda, MD, USA
| | - Jordane Dimidschstein
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Gord Fishell
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Kenneth A Pelkey
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Chris J McBain
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
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Blaine AT, van Rijn RM. Receptor expression and signaling properties in the brain, and structural ligand motifs that contribute to delta opioid receptor agonist-induced seizures. Neuropharmacology 2023; 232:109526. [PMID: 37004753 PMCID: PMC11078570 DOI: 10.1016/j.neuropharm.2023.109526] [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: 08/02/2022] [Revised: 03/10/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
The δ opioid receptor (δOR) is a therapeutic target for the treatment of various neurological disorders, such as migraines, chronic pain, alcohol use, and mood disorders. Relative to μ opioid receptor agonists, δOR agonists show lower abuse liability and may be potentially safer analgesic alternatives. However, currently no δOR agonists are approved for clinical use. A small number of δOR agonists reached Phase II trials, but ultimately failed to progress due to lack of efficacy. One side effect of δOR agonism that remains poorly understood is the ability of δOR agonists to produce seizures. The lack of a clear mechanism of action is partly driven by the fact that δOR agonists range in their propensity to induce seizure behavior, with multiple δOR agonists reportedly not causing seizures. There is a significant gap in our current understanding of why certain δOR agonists are more likely to induce seizures, and what signal-transduction pathway and/or brain area is engaged to produce these seizures. In this review we provide a comprehensive overview of the current state of knowledge of δOR agonist-mediated seizures. The review was structured to highlight which agonists produce seizures, which brain regions have been implicated and which signaling mediators have been examined in this behavior. Our hope is that this review will spur future studies that are carefully designed and aimed to solve the question why certain δOR agonists are seizurogenic. Obtaining such insight may expedite the development of novel δOR clinical candidates without the risk of inducing seizures. This article is part of the Special Issue on "Opioid-induced changes in addiction and pain circuits".
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Affiliation(s)
- Arryn T Blaine
- Purdue University, Department of Medicinal Chemistry and Molecular Pharmacology, West Lafayette, IN, 47907, USA; Purdue University Interdisciplinary Life Science graduate program, West Lafayette, IN, 47907, USA
| | - Richard M van Rijn
- Purdue University, Department of Medicinal Chemistry and Molecular Pharmacology, West Lafayette, IN, 47907, USA; Purdue Institute for Integrative Neuroscience, West Lafayette, IN, 47907, USA; Purdue Institute for Drug Discovery, West Lafayette, IN, 47907, USA; Septerna Inc., South San Francisco, CA, 94080, USA.
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Raghuraman R, Navakkode S, Sajikumar S. Alteration of hippocampal CA2 plasticity and social memory in adult rats impacted by juvenile stress. Hippocampus 2023; 33:745-758. [PMID: 36965045 PMCID: PMC10946601 DOI: 10.1002/hipo.23531] [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: 06/15/2022] [Revised: 03/09/2023] [Accepted: 03/11/2023] [Indexed: 03/27/2023]
Abstract
The hippocampal CA2 region has received greater attention in recent years due to its fundamental role in social memory and hippocampus-dependent memory processing. Unlike entorhinal cortical inputs, the Schaffer collateral inputs to CA2 do not support activity-dependent long-term potentiation (LTP), which serves as the basis for long-term memories. This LTP-resistant zone also expresses genes that restrict plasticity. With the aim of exploring social interaction and sociability in rats that were subjected to juvenile stress, we addressed questions about how the neural circuitry is altered and its effects on social behavior. Although there was induction of LTP in both Schaffer collateral and entorhinal cortical pathways in juvenile-stressed rats, LTP declined in both pathways after 2-3 h. Moreover, exogenous bath application of substance P, a neuropeptide that resulted in slow onset long-lasting potentiation in control animals while it failed to induce LTP in juvenile-stressed rats. Our study reveals that juvenile-stressed rats show behavioral and cellular abnormalities with a long-lasting impact in adulthood.
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Affiliation(s)
- Radha Raghuraman
- Department of PhysiologyNational University of SingaporeSingapore117593Singapore
- Life Sciences Institute Neurobiology ProgrammeCentre for Life Sciences, National University of SingaporeSingapore117456Singapore
- Present address:
Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNew York10032USA
| | - Sheeja Navakkode
- Lee Kong Chian School of MedicineNanyang Technological UniversitySingapore308232Singapore
| | - Sreedharan Sajikumar
- Department of PhysiologyNational University of SingaporeSingapore117593Singapore
- Life Sciences Institute Neurobiology ProgrammeCentre for Life Sciences, National University of SingaporeSingapore117456Singapore
- Healthy Longevity Translational Research ProgrammeYong Loo Lin School of Medicine, National University of SingaporeSingapore117456Singapore
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Hosseinzadeh Sahafi O, Sardari M, Alijanpour S, Rezayof A. Shared Mechanisms of GABAergic and Opioidergic Transmission Regulate Corticolimbic Reward Systems and Cognitive Aspects of Motivational Behaviors. Brain Sci 2023; 13:brainsci13050815. [PMID: 37239287 DOI: 10.3390/brainsci13050815] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/12/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
The functional interplay between the corticolimbic GABAergic and opioidergic systems plays a crucial role in regulating the reward system and cognitive aspects of motivational behaviors leading to the development of addictive behaviors and disorders. This review provides a summary of the shared mechanisms of GABAergic and opioidergic transmission, which modulate the activity of dopaminergic neurons located in the ventral tegmental area (VTA), the central hub of the reward mechanisms. This review comprehensively covers the neuroanatomical and neurobiological aspects of corticolimbic inhibitory neurons that express opioid receptors, which act as modulators of corticolimbic GABAergic transmission. The presence of opioid and GABA receptors on the same neurons allows for the modulation of the activity of dopaminergic neurons in the ventral tegmental area, which plays a key role in the reward mechanisms of the brain. This colocalization of receptors and their immunochemical markers can provide a comprehensive understanding for clinicians and researchers, revealing the neuronal circuits that contribute to the reward system. Moreover, this review highlights the importance of GABAergic transmission-induced neuroplasticity under the modulation of opioid receptors. It discusses their interactive role in reinforcement learning, network oscillation, aversive behaviors, and local feedback or feedforward inhibitions in reward mechanisms. Understanding the shared mechanisms of these systems may lead to the development of new therapeutic approaches for addiction, reward-related disorders, and drug-induced cognitive impairment.
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Affiliation(s)
- Oveis Hosseinzadeh Sahafi
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran 14155-6465, Iran
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Maryam Sardari
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran 14155-6465, Iran
| | - Sakineh Alijanpour
- Department of Biology, Faculty of Science, Gonbad Kavous University, Gonbad Kavous 4971799151, Iran
| | - Ameneh Rezayof
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran 14155-6465, Iran
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5
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Margolis EB, Moulton MG, Lambeth PS, O'Meara MJ. The life and times of endogenous opioid peptides: Updated understanding of synthesis, spatiotemporal dynamics, and the clinical impact in alcohol use disorder. Neuropharmacology 2023; 225:109376. [PMID: 36516892 PMCID: PMC10548835 DOI: 10.1016/j.neuropharm.2022.109376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 12/03/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
The opioid G-protein coupled receptors (GPCRs) strongly modulate many of the central nervous system structures that contribute to neurological and psychiatric disorders including pain, major depressive disorder, and substance use disorders. To better treat these and related diseases, it is essential to understand the signaling of their endogenous ligands. In this review, we focus on what is known and unknown about the regulation of the over two dozen endogenous peptides with high affinity for one or more of the opioid receptors. We briefly describe which peptides are produced, with a particular focus on the recently proposed possible synthesis pathways for the endomorphins. Next, we describe examples of endogenous opioid peptide expression organization in several neural circuits and how they appear to be released from specific neural compartments that vary across brain regions. We discuss current knowledge regarding the strength of neural activity required to drive endogenous opioid peptide release, clues about how far peptides diffuse from release sites, and their extracellular lifetime after release. Finally, as a translational example, we discuss the mechanisms of action of naltrexone (NTX), which is used clinically to treat alcohol use disorder. NTX is a synthetic morphine analog that non-specifically antagonizes the action of most endogenous opioid peptides developed in the 1960s and FDA approved in the 1980s. We review recent studies clarifying the precise endogenous activity that NTX prevents. Together, the works described here highlight the challenges and opportunities the complex opioid system presents as a therapeutic target.
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Affiliation(s)
- Elyssa B Margolis
- UCSF Weill Institute for Neurosciences, Department of Neurology, University of California, San Francisco, CA, USA; Neuroscience Graduate Program, University of California, San Francisco, CA, USA.
| | - Madelyn G Moulton
- UCSF Weill Institute for Neurosciences, Department of Neurology, University of California, San Francisco, CA, USA
| | - Philip S Lambeth
- UCSF Weill Institute for Neurosciences, Department of Neurology, University of California, San Francisco, CA, USA
| | - Matthew J O'Meara
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, 48109, USA
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Loisy M, Farah A, Fafouri A, Fanton A, Ahmadi M, Therreau L, Chevaleyre V, Piskorowski RA. Environmental enrichment and social isolation modulate inhibitory transmission and plasticity in hippocampal area CA2. Hippocampus 2023; 33:197-207. [PMID: 36374115 DOI: 10.1002/hipo.23478] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 10/03/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022]
Abstract
Environmental factors are well-accepted to play a complex and interdependent role with genetic factors in learning and memory. The goal of this study was to examine how environmental conditions altered synaptic plasticity in hippocampal area CA2. To do this, we housed adult mice for 3 weeks in an enriched environment (EE) consisting of a larger cage with running wheel, and regularly changed toys, tunnels and treats. We then performed whole-cell or extracellular field recordings in hippocampal area CA2 and compared the synaptic plasticity from EE-housed mice with slices from littermate controls housed in standard environment (SE). We found that the inhibitory transmission recruited by CA3 input stimulation in CA2 was significantly less plastic in EE conditions as compared to SE following an electrical tetanus. We demonstrate that delta-opioid receptor (DOR) mediated plasticity is reduced in EE conditions by direct application of DOR agonist. We show that in EE conditions the overall levels of GABA transmission is reduced in CA2 cells by analyzing inhibition of ErbB4 receptor, spontaneous inhibitory currents and paired-pulse ratio. Furthermore, we report that the effect of EE of synaptic plasticity can be rapidly reversed by social isolation. These results demonstrate how the neurons in hippocampal area CA2 are sensitive to environment and may lead to promising therapeutic targets.
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Affiliation(s)
- Maïthé Loisy
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Paris, France
| | - Amel Farah
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Paris, France
| | - Assia Fafouri
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Paris, France
| | - Aurélien Fanton
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Paris, France
| | - Mahboubeh Ahmadi
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Paris, France
| | - Ludivine Therreau
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Paris, France
| | - Vivien Chevaleyre
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Paris, France.,GHU Paris Psychiatrie et Neurosciences, Hôpital Sainte Anne, Paris, France
| | - Rebecca A Piskorowski
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Paris, France.,GHU Paris Psychiatrie et Neurosciences, Hôpital Sainte Anne, Paris, France
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Shinohara Y, Kohara K. Projections of hippocampal CA2 pyramidal neurons: Distinct innervation patterns of CA2 compared to CA3 in rodents. Hippocampus 2023; 33:691-699. [PMID: 36855258 DOI: 10.1002/hipo.23519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 02/01/2023] [Accepted: 02/14/2023] [Indexed: 03/02/2023]
Abstract
The hippocampus is a center for spatial and episodic memory formation in rodents. Understanding the composition of subregions and circuitry maps of the hippocampus is essential for elucidating the mechanism of memory formation and recall. For decades, the trisynaptic circuit (entorhinal cortex layer II-dentate gyrus - CA3-CA1) has been considered the neural network substrate responsible for learning and memory. Recently, CA2 has emerged as an important area in the hippocampal circuitry, with distinct functions from those of CA3. In this article, we review the historical definition of the hippocampal area CA2 and the differential projection patterns between CA2 and CA3 pyramidal neurons. We provide a concise and comprehensive map of CA2 outputs by comparing (1) ipsi versus contra projections, (2) septal versus temporal projections, and (3) lamellar structures of CA2 and CA3 pyramidal neurons.
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Affiliation(s)
- Yoshiaki Shinohara
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Keigo Kohara
- KMU Biobank Center, Institute of Biomedical Science, Kansai Medical University, Hirakata, Osaka, Japan
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Černotová D, Hrůzová K, Levčík D, Svoboda J, Stuchlík A. Linking Social Cognition, Parvalbumin Interneurons, and Oxytocin in Alzheimer's Disease: An Update. J Alzheimers Dis 2023; 96:861-875. [PMID: 37980658 PMCID: PMC10741376 DOI: 10.3233/jad-230333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2023] [Indexed: 11/21/2023]
Abstract
Finding a cure for Alzheimer's disease (AD) has been notoriously challenging for many decades. Therefore, the current focus is mainly on prevention, timely intervention, and slowing the progression in the earliest stages. A better understanding of underlying mechanisms at the beginning of the disease could aid in early diagnosis and intervention, including alleviating symptoms or slowing down the disease progression. Changes in social cognition and progressive parvalbumin (PV) interneuron dysfunction are among the earliest observable effects of AD. Various AD rodent models mimic these early alterations, but only a narrow field of study has considered their mutual relationship. In this review, we discuss current knowledge about PV interneuron dysfunction in AD and emphasize their importance in social cognition and memory. Next, we propose oxytocin (OT) as a potent modulator of PV interneurons and as a promising treatment for managing some of the early symptoms. We further discuss the supporting evidence on its beneficial effects on AD-related pathology. Clinical trials have employed the use of OT in various neuropsychiatric diseases with promising results, but little is known about its prospective impacts on AD. On the other hand, the modulatory effects of OT in specific structures and local circuits need to be clarified in future studies. This review highlights the connection between PV interneurons and social cognition impairment in the early stages of AD and considers OT as a promising therapeutic agent for addressing these early deficits.
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Affiliation(s)
- Daniela Černotová
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Karolína Hrůzová
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - David Levčík
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Svoboda
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Aleš Stuchlík
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
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9
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Piskorowski RA, Chevaleyre V. Hippocampal area CA2: interneuron disfunction during pathological states. Front Neural Circuits 2023; 17:1181032. [PMID: 37180763 PMCID: PMC10174260 DOI: 10.3389/fncir.2023.1181032] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/07/2023] [Indexed: 05/16/2023] Open
Abstract
Hippocampal area CA2 plays a critical role in social recognition memory and has unique cellular and molecular properties that distinguish it from areas CA1 and CA3. In addition to having a particularly high density of interneurons, the inhibitory transmission in this region displays two distinct forms of long-term synaptic plasticity. Early studies on human hippocampal tissue have reported unique alteration in area CA2 with several pathologies and psychiatric disorders. In this review, we present recent studies revealing changes in inhibitory transmission and plasticity of area CA2 in mouse models of multiple sclerosis, autism spectrum disorder, Alzheimer's disease, schizophrenia and the 22q11.2 deletion syndrome and propose how these changes could underly deficits in social cognition observed during these pathologies.
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Affiliation(s)
- Rebecca A. Piskorowski
- Université Paris Cité, INSERM UMRS 1266, Institute of Psychiatry and Neuroscience of Paris, GHU Paris Psychiatrie et Neurosciences, Paris, France
- Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR 8246, INSERM U1130, Sorbonne Université, Paris, France
- *Correspondence: Rebecca A. Piskorowski,
| | - Vivien Chevaleyre
- Université Paris Cité, INSERM UMRS 1266, Institute of Psychiatry and Neuroscience of Paris, GHU Paris Psychiatrie et Neurosciences, Paris, France
- Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR 8246, INSERM U1130, Sorbonne Université, Paris, France
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10
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Blaine AT, Miao Y, Yuan J, Palant S, Liu RJ, Zhang ZY, van Rijn RM. Exploration of beta-arrestin isoform signaling pathways in delta opioid receptor agonist-induced convulsions. Front Pharmacol 2022; 13:914651. [PMID: 36059958 PMCID: PMC9428791 DOI: 10.3389/fphar.2022.914651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/13/2022] [Indexed: 11/17/2022] Open
Abstract
The δ-opioid receptor (δOR) has been considered as a therapeutic target in multiple neurological and neuropsychiatric disorders particularly as δOR agonists are deemed safer alternatives relative to the more abuse-liable µ-opioid receptor drugs. Clinical development of δOR agonists, however, has been challenging in part due to the seizure-inducing effects of certain δOR agonists. Especially agonists that resemble the δOR-selective agonist SNC80 have well-established convulsive activity. Close inspection suggests that many of those seizurogenic δOR agonists efficaciously recruit β-arrestin, yet surprisingly, SNC80 displays enhanced seizure activity in β-arrestin 1 knockout mice. This finding led us to hypothesize that perhaps β-arrestin 1 is protective against, whereas β-arrestin 2 is detrimental for δOR-agonist-induced seizures. To investigate our hypothesis, we characterized three different δOR agonists (SNC80, ADL5859, ARM390) in cellular assays and in vivo in wild-type and β-arrestin 1 and β-arrestin 2 knockout mice for seizure activity. We also investigated downstream kinases associated with β-arrestin-dependent signal transduction. We discovered that δOR agonist-induced seizure activity strongly and positively correlates with β-arrestin 2 efficacy for the agonist, but that indirect inhibition of ERK activation using the MEK inhibitor SL327 did not inhibit seizure potency and duration. Inhibition of the PI3K/AKT/mTOR signaling with honokiol but not PQR530, attenuated SNC80 seizure duration in β-arrestin 1 knockout, but honokiol did not reduce SNC80-induced seizures in wild-type mice. Ultimately, our results indicate that β-arrestin 2 is correlated with δOR agonist-induced seizure intensity, but that global β-arrestin 1 knockout mice are a poor model system to investigate their mechanism of action.
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Affiliation(s)
- Arryn T. Blaine
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
- Purdue Interdisciplinary Life Sciences Graduate Program, West Lafayette, IN, United States
| | - Yiming Miao
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
| | - Jinling Yuan
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
| | - Sophia Palant
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
| | - Rebecca J. Liu
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
| | - Zhong-Yin Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
- Purdue Institute for Drug Discovery, West Lafayette, IN, United States
- Purdue University Cancer Center, West Lafayette, IN, United States
| | - Richard. M. van Rijn
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
- Purdue Institute for Drug Discovery, West Lafayette, IN, United States
- Purdue University Cancer Center, West Lafayette, IN, United States
- Purdue Institute for Integrative Neuroscience, West Lafayette, IN, United States
- *Correspondence: Richard. M. van Rijn,
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Loisy M, Bouisset G, Lopez S, Muller M, Spitsyn A, Duval J, Piskorowski RA, Verret L, Chevaleyre V. Sequential inhibitory plasticities in hippocampal area CA2 and social memory formation. Neuron 2022; 110:2854-2866.e4. [PMID: 35858622 DOI: 10.1016/j.neuron.2022.06.013] [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: 09/21/2021] [Revised: 04/22/2022] [Accepted: 06/10/2022] [Indexed: 11/25/2022]
Abstract
Area CA2 is a critical region for diverse hippocampal functions including social recognition memory. This region has unique properties and connectivity. Notably, intra-hippocampal excitatory inputs to CA2 lack canonical long-term plasticity, but inhibitory transmission expresses a long-term depression mediated by Delta-opioid receptors (DOR-iLTDs). Evidence indicates that DOR-iLTDs are insufficient to underlie social coding. Here, we report a novel inhibitory plasticity mediated by cannabinoid type 1 receptor activation (CB1R-iLTD). Surprisingly, CB1R-iLTD requires previous induction of DOR-iLTDs, indicating a permissive role for DOR plasticity. Blockade of CB1Rs in CA2 completely prevents social memory formation. Furthermore, the sequentiality of DOR- and CB1R-mediated plasticity occurs in vivo during successive social interactions. Finally, CB1R-iLTD is altered in a mouse model of schizophrenia with impaired social cognition but is rescued by a manipulation that also rescues social memory. Altogether, our data reveal a unique interplay between two inhibitory plasticities and a novel mechanism for social memory formation.
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Affiliation(s)
- Maïthé Loisy
- Université Paris Cité, INSERM U1266, Institute of Psychiatry and Neuroscience of Paris, 75014 Paris, France
| | - Guillaume Bouisset
- Research Center on Animal Cognition, Center for Integrative Biology, Toulouse University, CNRS, UPS, 31062 Toulouse, France
| | - Sébastien Lopez
- Research Center on Animal Cognition, Center for Integrative Biology, Toulouse University, CNRS, UPS, 31062 Toulouse, France
| | - Maud Muller
- Université Paris Cité, INSERM U1266, Institute of Psychiatry and Neuroscience of Paris, 75014 Paris, France
| | - Alena Spitsyn
- Université Paris Cité, INSERM U1266, Institute of Psychiatry and Neuroscience of Paris, 75014 Paris, France
| | - Jeanne Duval
- Université Paris Cité, INSERM U1266, Institute of Psychiatry and Neuroscience of Paris, 75014 Paris, France
| | - Rebecca Ann Piskorowski
- Université Paris Cité, INSERM U1266, Institute of Psychiatry and Neuroscience of Paris, 75014 Paris, France; GHU Paris Psychiatrie et Neurosciences, France
| | - Laure Verret
- Research Center on Animal Cognition, Center for Integrative Biology, Toulouse University, CNRS, UPS, 31062 Toulouse, France
| | - Vivien Chevaleyre
- Université Paris Cité, INSERM U1266, Institute of Psychiatry and Neuroscience of Paris, 75014 Paris, France; GHU Paris Psychiatrie et Neurosciences, France.
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12
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Reeves KC, Shah N, Muñoz B, Atwood BK. Opioid Receptor-Mediated Regulation of Neurotransmission in the Brain. Front Mol Neurosci 2022; 15:919773. [PMID: 35782382 PMCID: PMC9242007 DOI: 10.3389/fnmol.2022.919773] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/26/2022] [Indexed: 12/15/2022] Open
Abstract
Opioids mediate their effects via opioid receptors: mu, delta, and kappa. At the neuronal level, opioid receptors are generally inhibitory, presynaptically reducing neurotransmitter release and postsynaptically hyperpolarizing neurons. However, opioid receptor-mediated regulation of neuronal function and synaptic transmission is not uniform in expression pattern and mechanism across the brain. The localization of receptors within specific cell types and neurocircuits determine the effects that endogenous and exogenous opioids have on brain function. In this review we will explore the similarities and differences in opioid receptor-mediated regulation of neurotransmission across different brain regions. We discuss how future studies can consider potential cell-type, regional, and neural pathway-specific effects of opioid receptors in order to better understand how opioid receptors modulate brain function.
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Affiliation(s)
- Kaitlin C. Reeves
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Neuroscience, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, United States
| | - Nikhil Shah
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Medical Scientist Training Program, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Braulio Muñoz
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Brady K. Atwood
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
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13
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Enkephalin release from VIP interneurons in the hippocampal CA2/3a region mediates heterosynaptic plasticity and social memory. Mol Psychiatry 2022; 27:2879-2900. [PMID: 33990774 PMCID: PMC8590711 DOI: 10.1038/s41380-021-01124-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 03/23/2021] [Accepted: 04/13/2021] [Indexed: 12/22/2022]
Abstract
The hippocampus contains a diverse array of inhibitory interneurons that gate information flow through local cortico-hippocampal circuits to regulate memory storage. Although most studies of interneurons have focused on their role in fast synaptic inhibition mediated by GABA release, different classes of interneurons express unique sets of neuropeptides, many of which have been shown to exert powerful effects on neuronal function and memory when applied pharmacologically. However, relatively little is known about whether and how release of endogenous neuropeptides from inhibitory cells contributes to their behavioral role in regulating memory formation. Here we report that vasoactive intestinal peptide (VIP)-expressing interneurons participate in social memory storage by enhancing information transfer from hippocampal CA3 pyramidal neurons to CA2 pyramidal neurons. Notably, this action depends on release of the neuropeptide enkephalin from VIP neurons, causing long-term depression of feedforward inhibition onto CA2 pyramidal cells. Moreover, VIP neuron activity in the CA2 region is increased selectively during exploration of a novel conspecific. Our findings, thus, enhance our appreciation of how GABAergic neurons can regulate synaptic plasticity and mnemonic behavior by demonstrating that such actions can be mediated by release of a specific neuropeptide, rather than through classic fast inhibitory transmission.
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14
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Benoy A, Wong LW, Ather N, Sajikumar S. Serotonin facilitates late-associative plasticity via synaptic tagging/cross-tagging and capture at hippocampal CA2 synapses in male rats. OXFORD OPEN NEUROSCIENCE 2022; 1:kvac002. [PMID: 38596711 PMCID: PMC10913837 DOI: 10.1093/oons/kvac002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/24/2022] [Accepted: 02/02/2022] [Indexed: 04/11/2024]
Abstract
Synaptic plasticity in the hippocampal Cornu Ammonis (CA) subfield, CA2, is tightly regulated. However, CA2 receives projections from several extra-hippocampal modulatory nuclei that release modulators that could serve to fine-tune plasticity at CA2 synapses. Considering that there are afferent projections from the serotonergic median raphe to hippocampal CA2, we hypothesized that the neuromodulator serotonin (5-hydroxytryptamine; 5-HT) could modulate CA2 synaptic plasticity. Here, we show that bath-application of serotonin facilitates the persistence of long-term depression (LTD) at the CA3 Schaffer collateral inputs to CA2 neurons (SC-CA2) when coupled to a weak low frequency electrical stimulation, in acute rat hippocampal slices. The observed late-LTD at SC-CA2 synapses was protein synthesis- and N-methyl-D-aspartate receptor (NMDAR)-dependent. Moreover, this late-LTD at SC-CA2 synapses paves way for the associative persistence of transient forms of LTD as well as long-term potentiation to long-lasting late forms of plasticity through synaptic tagging and cross-tagging respectively, at the entorhinal cortical synapses of CA2. We further observe that the 5-HT-mediated persistence of activity-dependent LTD at SC-CA2 synapses is blocked in the presence of the brain-derived neurotrophic factor scavenger, TrkB/Fc.
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Affiliation(s)
- Amrita Benoy
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore
- Life Sciences Institute Neurobiology Programme, National University of Singapore, 117456 Singapore
| | - Lik-Wei Wong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore
- Life Sciences Institute Neurobiology Programme, National University of Singapore, 117456 Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 117456 Singapore
| | - Niha Ather
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore
- Life Sciences Institute Neurobiology Programme, National University of Singapore, 117456 Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore
- Life Sciences Institute Neurobiology Programme, National University of Singapore, 117456 Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 117456 Singapore
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15
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Rey CC, Robert V, Bouisset G, Loisy M, Lopez S, Cattaud V, Lejards C, Piskorowski RA, Rampon C, Chevaleyre V, Verret L. Altered inhibitory function in hippocampal CA2 contributes in social memory deficits in Alzheimer’s mouse model. iScience 2022; 25:103895. [PMID: 35243253 PMCID: PMC8873612 DOI: 10.1016/j.isci.2022.103895] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 12/07/2021] [Accepted: 02/07/2022] [Indexed: 11/10/2022] Open
Abstract
Parvalbumin (PV)-expressing interneurons which are often associated with the specific extracellular matrix perineuronal net (PNN) play a critical role in the alteration of brain activity and memory performance in Alzheimer’s disease (AD). The integrity of these neurons is crucial for normal functioning of the hippocampal subfield CA2, and hence, social memory formation. Here, we find that social memory deficits of mouse models of AD are associated with decreased presence of PNN around PV cells and long-term synaptic plasticity in area CA2. Furthermore, single local injection of the growth factor neuregulin-1 (NRG1) is sufficient to restore both PV/PNN levels and social memory performance of these mice. Thus, the PV/PNN disruption in area CA2 could play a causal role in social memory deficits of AD mice, and activating PV cell pro-maturation pathways may be sufficient to restore social memory. Tg2576 mouse model of AD have normal sociability, but cannot form social memory Tg2576 mice have less detectable PV interneurons and PNN in hippocampal area CA2 PV-dependent long-term plasticity is altered in CA2 of Tg2576 mice NRG1 in CA2 increases PV/PNN and restores social memory of these AD mice
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16
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He XJ, Patel J, Weiss CE, Ma X, Bloodgood BL, Banghart MR. Convergent, functionally independent signaling by mu and delta opioid receptors in hippocampal parvalbumin interneurons. eLife 2021; 10:69746. [PMID: 34787079 PMCID: PMC8716102 DOI: 10.7554/elife.69746] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/16/2021] [Indexed: 11/13/2022] Open
Abstract
Functional interactions between G protein-coupled receptors are poised to enhance neuronal sensitivity to neuromodulators and therapeutic drugs. Mu and Delta opioid receptors (MORs and DORs) can interact when overexpressed in the same cells, but whether co-expression of endogenous MORs and DORs in neurons leads to functional interactions is unclear. Here, in mice, we show that both MORs and DORs inhibit parvalbumin-expressing basket cells (PV-BCs) in hippocampal CA1 through partially occlusive signaling pathways that terminate on somato-dendritic potassium channels and presynaptic calcium channels. Using photoactivatable opioid neuropeptides, we find that DORs dominate the response to enkephalin in terms of both ligand-sensitivity and kinetics, which may be due to relatively low expression levels of MOR. Opioid-activated potassium channels do not show heterologous desensitization, indicating that MORs and DORs signal independently. In a direct test for heteromeric functional interactions, the DOR antagonist TIPP-Psi does not alter the kinetics or potency of either the potassium channel or synaptic responses to photorelease of the MOR agonist DAMGO. Thus, aside from largely redundant and convergent signaling, MORs and DORs do not functionally interact in PV-BCs in a way that impacts somato-dendritic potassium currents or synaptic transmission. These findings imply that crosstalk between MORs and DORs, either in the form of physical interactions or synergistic intracellular signaling, is not a preordained outcome of co-expression in neurons.
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Affiliation(s)
- Xinyi Jenny He
- Biological Sciences, University of California San Diego, La Jolla, United States
| | - Janki Patel
- University of California San Diego, San Diego, United States
| | - Connor E Weiss
- University of California San Diego, San Diego, United States
| | - Xiang Ma
- University of California San Diego, San Diego, United States
| | - Brenda L Bloodgood
- Biological Sciences, University of California San Diego, La Jolla, United States
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17
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Complement-associated loss of CA2 inhibitory synapses in the demyelinated hippocampus impairs memory. Acta Neuropathol 2021; 142:643-667. [PMID: 34170374 PMCID: PMC8423657 DOI: 10.1007/s00401-021-02338-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 06/03/2021] [Accepted: 06/14/2021] [Indexed: 12/27/2022]
Abstract
The complement system is implicated in synapse loss in the MS hippocampus, but the functional consequences of synapse loss remain poorly understood. Here, in post-mortem MS hippocampi with demyelination we find that deposits of the complement component C1q are enriched in the CA2 subfield, are linked to loss of inhibitory synapses and are significantly higher in MS patients with cognitive impairments compared to those with preserved cognitive functions. Using the cuprizone mouse model of demyelination, we corroborated that C1q deposits are highest within the demyelinated dorsal hippocampal CA2 pyramidal layer and co-localized with inhibitory synapses engulfed by microglia/macrophages. In agreement with the loss of inhibitory perisomatic synapses, we found that Schaffer collateral feedforward inhibition but not excitation was impaired in CA2 pyramidal neurons and accompanied by intrinsic changes and a reduced spike output. Finally, consistent with excitability deficits, we show that cuprizone-treated mice exhibit impaired encoding of social memories. Together, our findings identify CA2 as a critical circuit in demyelinated intrahippocampal lesions and memory dysfunctions in MS.
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18
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RGS14 Regulation of Post-Synaptic Signaling and Spine Plasticity in Brain. Int J Mol Sci 2021; 22:ijms22136823. [PMID: 34201943 PMCID: PMC8268017 DOI: 10.3390/ijms22136823] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/12/2021] [Accepted: 06/14/2021] [Indexed: 02/06/2023] Open
Abstract
The regulator of G-protein signaling 14 (RGS14) is a multifunctional signaling protein that regulates post synaptic plasticity in neurons. RGS14 is expressed in the brain regions essential for learning, memory, emotion, and stimulus-induced behaviors, including the basal ganglia, limbic system, and cortex. Behaviorally, RGS14 regulates spatial and object memory, female-specific responses to cued fear conditioning, and environmental- and psychostimulant-induced locomotion. At the cellular level, RGS14 acts as a scaffolding protein that integrates G protein, Ras/ERK, and calcium/calmodulin signaling pathways essential for spine plasticity and cell signaling, allowing RGS14 to naturally suppress long-term potentiation (LTP) and structural plasticity in hippocampal area CA2 pyramidal cells. Recent proteomics findings indicate that RGS14 also engages the actomyosin system in the brain, perhaps to impact spine morphogenesis. Of note, RGS14 is also a nucleocytoplasmic shuttling protein, where its role in the nucleus remains uncertain. Balanced nuclear import/export and dendritic spine localization are likely essential for RGS14 neuronal functions as a regulator of synaptic plasticity. Supporting this idea, human genetic variants disrupting RGS14 localization also disrupt RGS14’s effects on plasticity. This review will focus on the known and unexplored roles of RGS14 in cell signaling, physiology, disease and behavior.
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19
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Robert V, Therreau L, Chevaleyre V, Lepicard E, Viollet C, Cognet J, Huang AJ, Boehringer R, Polygalov D, McHugh TJ, Piskorowski RA. Local circuit allowing hypothalamic control of hippocampal area CA2 activity and consequences for CA1. eLife 2021; 10:63352. [PMID: 34003113 PMCID: PMC8154026 DOI: 10.7554/elife.63352] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 05/17/2021] [Indexed: 12/28/2022] Open
Abstract
The hippocampus is critical for memory formation. The hypothalamic supramammillary nucleus (SuM) sends long-range projections to hippocampal area CA2. While the SuM-CA2 connection is critical for social memory, how this input acts on the local circuit is unknown. Using transgenic mice, we found that SuM axon stimulation elicited mixed excitatory and inhibitory responses in area CA2 pyramidal neurons (PNs). Parvalbumin-expressing basket cells were largely responsible for the feedforward inhibitory drive of SuM over area CA2. Inhibition recruited by the SuM input onto CA2 PNs increased the precision of action potential firing both in conditions of low and high cholinergic tone. Furthermore, SuM stimulation in area CA2 modulated CA1 activity, indicating that synchronized CA2 output drives a pulsed inhibition in area CA1. Hence, the network revealed here lays basis for understanding how SuM activity directly acts on the local hippocampal circuit to allow social memory encoding.
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Affiliation(s)
- Vincent Robert
- INSERM UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Université de Paris, Paris, France
| | - Ludivine Therreau
- INSERM UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Université de Paris, Paris, France
| | - Vivien Chevaleyre
- INSERM UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Université de Paris, Paris, France.,GHU Paris Psychiatrie and Neurosciences, Paris, France
| | - Eude Lepicard
- INSERM UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Université de Paris, Paris, France
| | - Cécile Viollet
- INSERM UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Université de Paris, Paris, France
| | - Julie Cognet
- INSERM UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Université de Paris, Paris, France
| | - Arthur Jy Huang
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Roman Boehringer
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Denis Polygalov
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Rebecca Ann Piskorowski
- INSERM UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Université de Paris, Paris, France.,GHU Paris Psychiatrie and Neurosciences, Paris, France
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20
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Lehr AB, Kumar A, Tetzlaff C, Hafting T, Fyhn M, Stöber TM. CA2 beyond social memory: Evidence for a fundamental role in hippocampal information processing. Neurosci Biobehav Rev 2021; 126:398-412. [PMID: 33775693 DOI: 10.1016/j.neubiorev.2021.03.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 01/16/2023]
Abstract
Hippocampal region CA2 has received increased attention due to its importance in social recognition memory. While its specific function remains to be identified, there are indications that CA2 plays a major role in a variety of situations, widely extending beyond social memory. In this targeted review, we highlight lines of research which have begun to converge on a more fundamental role for CA2 in hippocampus-dependent memory processing. We discuss recent proposals that speak to the computations CA2 may perform within the hippocampal circuit.
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Affiliation(s)
- Andrew B Lehr
- Department of Computational Neuroscience, University of Göttingen, Germany; Bernstein Center for Computational Neuroscience, University of Göttingen, Germany; Department of Computational Physiology, Simula Research Laboratory, Lysaker, Norway; Centre for Integrative Neuroplasticity, University of Oslo, Norway.
| | - Arvind Kumar
- Department of Computational Science and Technology, KTH Royal Institute of Technology, Sweden
| | - Christian Tetzlaff
- Department of Computational Neuroscience, University of Göttingen, Germany; Bernstein Center for Computational Neuroscience, University of Göttingen, Germany
| | - Torkel Hafting
- Centre for Integrative Neuroplasticity, University of Oslo, Norway; Institute of Basic Medical Sciences, University of Oslo, Norway
| | - Marianne Fyhn
- Centre for Integrative Neuroplasticity, University of Oslo, Norway; Department of Biosciences, University of Oslo, Norway
| | - Tristan M Stöber
- Department of Computational Physiology, Simula Research Laboratory, Lysaker, Norway; Centre for Integrative Neuroplasticity, University of Oslo, Norway; Department of Informatics, University of Oslo, Norway.
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21
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Stöber TM, Lehr AB, Hafting T, Kumar A, Fyhn M. Selective neuromodulation and mutual inhibition within the
CA3–CA2
system can prioritize sequences for replay. Hippocampus 2020; 30:1228-1238. [DOI: 10.1002/hipo.23256] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/10/2020] [Accepted: 08/07/2020] [Indexed: 11/06/2022]
Affiliation(s)
- Tristan M. Stöber
- Department of Computational Physiology Simula Research Laboratory Lysaker Norway
- Centre for Integrative Neuroplasticity University of Oslo Oslo Norway
- Department of Informatics University of Oslo Oslo Norway
| | - Andrew B. Lehr
- Department of Computational Physiology Simula Research Laboratory Lysaker Norway
- Centre for Integrative Neuroplasticity University of Oslo Oslo Norway
- Department of Computational Neuroscience University of Göttingen Göttingen Germany
| | - Torkel Hafting
- Centre for Integrative Neuroplasticity University of Oslo Oslo Norway
- Institute of Basic Medical Sciences University of Oslo Oslo Norway
| | - Arvind Kumar
- Department of Computational Science and Technology KTH Royal Institute of Technology Stockholm Sweden
| | - Marianne Fyhn
- Centre for Integrative Neuroplasticity University of Oslo Oslo Norway
- Department of Biosciences University of Oslo Oslo Norway
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22
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Capogna M, Castillo PE, Maffei A. The ins and outs of inhibitory synaptic plasticity: Neuron types, molecular mechanisms and functional roles. Eur J Neurosci 2020; 54:6882-6901. [PMID: 32663353 DOI: 10.1111/ejn.14907] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 06/30/2020] [Accepted: 07/08/2020] [Indexed: 01/05/2023]
Abstract
GABAergic interneurons are highly diverse, and their synaptic outputs express various forms of plasticity. Compelling evidence indicates that activity-dependent changes of inhibitory synaptic transmission play a significant role in regulating neural circuits critically involved in learning and memory and circuit refinement. Here, we provide an updated overview of inhibitory synaptic plasticity with a focus on the hippocampus and neocortex. To illustrate the diversity of inhibitory interneurons, we discuss the case of two highly divergent interneuron types, parvalbumin-expressing basket cells and neurogliaform cells, which support unique roles on circuit dynamics. We also present recent progress on the molecular mechanisms underlying long-term, activity-dependent plasticity of fast inhibitory transmission. Lastly, we discuss the role of inhibitory synaptic plasticity in neuronal circuits' function. The emerging picture is that inhibitory synaptic transmission in the CNS is extremely diverse, undergoes various mechanistically distinct forms of plasticity and contributes to a much more refined computational role than initially thought. Both the remarkable diversity of inhibitory interneurons and the various forms of plasticity expressed by GABAergic synapses provide an amazingly rich inhibitory repertoire that is central to a variety of complex neural circuit functions, including memory.
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Affiliation(s)
- Marco Capogna
- Department of Biomedicine, Danish National Research Foundation Center of Excellence PROMEMO, Aarhus University, Aarhus, Denmark
| | - Pablo E Castillo
- Dominck P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Arianna Maffei
- Center for Neural Circuit Dynamics and Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
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23
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Mu-Opioids Suppress GABAergic Synaptic Transmission onto Orbitofrontal Cortex Pyramidal Neurons with Subregional Selectivity. J Neurosci 2020; 40:5894-5907. [PMID: 32601247 DOI: 10.1523/jneurosci.2049-19.2020] [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: 08/23/2019] [Revised: 06/15/2020] [Accepted: 06/15/2020] [Indexed: 12/22/2022] Open
Abstract
The orbitofrontal cortex (OFC) plays a critical role in evaluating outcomes in a changing environment. Administering opioids to the OFC can alter the hedonic reaction to food rewards and increase their consumption in a subregion-specific manner. However, it is unknown how mu-opioid signaling influences synaptic transmission in the OFC. Thus, we investigated the cellular actions of mu-opioids within distinct subregions of the OFC. Using in vitro patch-clamp electrophysiology in brain slices containing the OFC, we found that the mu-opioid agonist DAMGO produced a concentration-dependent inhibition of GABAergic synaptic transmission onto medial OFC (mOFC), but not lateral OFC (lOFC) neurons. This effect was mediated by presynaptic mu-opioid receptor activation of local parvalbumin (PV+)-expressing interneurons. The DAMGO-induced suppression of inhibition was long lasting and not reversed on washout of DAMGO or by application of the mu-opioid receptor antagonist CTAP, suggesting an inhibitory long-term depression (LTD) induced by an exogenous mu-opioid. We show that LTD at inhibitory synapses is dependent on downstream cAMP/protein kinase A (PKA) signaling, which differs between the mOFC and lOFC. Finally, we demonstrate that endogenous opioid release triggered via moderate physiological stimulation can induce LTD. Together, these results suggest that presynaptic mu-opioid stimulation of local PV+ interneurons induces a long-lasting suppression of GABAergic synaptic transmission, which depends on subregional differences in mu-opioid receptor coupling to the downstream cAMP/PKA intracellular cascade. These findings provide mechanistic insight into the opposing functional effects produced by mu-opioids within the OFC.SIGNIFICANCE STATEMENT Considering that both the orbitofrontal cortex (OFC) and the opioid system regulate reward, motivation, and food intake, understanding the role of opioid signaling within the OFC is fundamental for a mechanistic understanding of the sequelae for several psychiatric disorders. This study makes several novel observations. First, mu-opioids induce a long-lasting suppression of inhibitory synaptic transmission onto OFC pyramidal neurons in a regionally selective manner. Second, mu-opioids recruit parvalbumin inputs to suppress inhibitory synaptic transmission in the mOFC. Third, the regional selectivity of mu-opioid action of endogenous opioids is due to the efficacy of mu-opioid receptor coupling to the downstream cAMP/PKA intracellular cascades. These experiments are the first to reveal a cellular mechanism of opioid action within the OFC.
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24
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Caruana DA, Dudek SM. Adenosine A 1 Receptor-Mediated Synaptic Depression in the Developing Hippocampal Area CA2. Front Synaptic Neurosci 2020; 12:21. [PMID: 32612520 PMCID: PMC7307308 DOI: 10.3389/fnsyn.2020.00021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/04/2020] [Indexed: 12/22/2022] Open
Abstract
Immunolabeling for adenosine A1 receptors (A1Rs) is high in hippocampal area CA2 in adult rats, and the potentiating effects of caffeine or other A1R-selective antagonists on synaptic responses are particularly robust at Schaffer collateral synapses in CA2. Interestingly, the pronounced staining for A1Rs in CA2 is not apparent until rats are 4 weeks old, suggesting that developmental changes other than receptor distribution underlie the sensitivity of CA2 synapses to A1R antagonists in young animals. To evaluate the role of A1R-mediated postsynaptic signals at these synapses, we tested whether A1R agonists regulate synaptic transmission at Schaffer collateral inputs to CA2 and CA1. We found that the selective A1R agonist CCPA caused a lasting depression of synaptic responses in both CA2 and CA1 neurons in slices obtained from juvenile rats (P14), but that the effect was observed only in CA2 in slices prepared from adult animals (~P70). Interestingly, blocking phosphodiesterase activity with rolipram inhibited the CCPA-induced depression in CA1, but not in CA2, indicative of robust phosphodiesterase activity in CA1 neurons. Likewise, synaptic responses in CA2 and CA1 differed in their sensitivity to the adenylyl cyclase activator, forskolin, in that it increased synaptic transmission in CA2, but had little effect in CA1. These findings suggest that the A1R-mediated synaptic depression tracks the postnatal development of immunolabeling for A1Rs and that the enhanced sensitivity to antagonists in CA2 at young ages is likely due to robust adenylyl cyclase activity and weak phosphodiesterase activity rather than to enrichment of A1Rs.
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Affiliation(s)
- Douglas A. Caruana
- School of Life and Health Sciences, Aston University, Birmingham, United Kingdom
- Neurobiology Laboratory, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health, Research Triangle Park, NC, United States
| | - Serena M. Dudek
- Neurobiology Laboratory, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health, Research Triangle Park, NC, United States
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Fernandez-Lamo I, Gomez-Dominguez D, Sanchez-Aguilera A, Oliva A, Morales AV, Valero M, Cid E, Berenyi A, Menendez de la Prida L. Proximodistal Organization of the CA2 Hippocampal Area. Cell Rep 2020; 26:1734-1746.e6. [PMID: 30759386 PMCID: PMC6389459 DOI: 10.1016/j.celrep.2019.01.060] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 10/25/2018] [Accepted: 01/15/2019] [Indexed: 12/13/2022] Open
Abstract
The proximodistal axis is considered a major organizational principle of the hippocampus. At the interface between the hippocampus and other brain structures, CA2 apparently breaks this rule. The region is involved in social, temporal, and contextual memory function, but mechanisms remain elusive. Here, we reveal cell-type heterogeneity and a characteristic expression gradient of the transcription factor Sox5 within CA2 in the rat. Using intracellular and extracellular recordings followed by neurochemical identification of single cells, we find marked proximodistal trends of synaptic activity, subthreshold membrane potentials, and phase-locked firing coupled to theta and gamma oscillations. Phase-shifting membrane potentials and opposite proximodistal correlations with theta sinks and sources at different layers support influences from different current generators. CA2 oscillatory activity and place coding of rats running in a linear maze reflect proximodistal state-dependent trends. We suggest that the structure and function of CA2 are distributed along the proximodistal hippocampal axis. The CA2 region is organized around the limit of the mossy fibers Heterogeneous pyramidal cell types populate the proximal and distal CA2 region Responses to intra- and extra-hippocampal inputs segregate along this axis CA2 oscillatory activity and spatial coding change proximodistally
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Affiliation(s)
| | | | | | - Azahara Oliva
- Department of Neuroscience, Zuckerman and Kavli Institutes, Columbia University, 3227 Broadway, New York, NY 10027, USA
| | | | - Manuel Valero
- Instituto Cajal, CSIC, Ave Doctor Arce 37, Madrid 28002, Spain
| | - Elena Cid
- Instituto Cajal, CSIC, Ave Doctor Arce 37, Madrid 28002, Spain
| | - Antal Berenyi
- MTA-SZTE "Momentum" Oscillatory Neuronal Networks Research Group, Interdisciplinary Excellence Centre, Department of Physiology, University of Szeged, Szeged 6720, Hungary
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26
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Young WS, Song J. Characterization of Oxytocin Receptor Expression Within Various Neuronal Populations of the Mouse Dorsal Hippocampus. Front Mol Neurosci 2020; 13:40. [PMID: 32256314 PMCID: PMC7093644 DOI: 10.3389/fnmol.2020.00040] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/28/2020] [Indexed: 11/30/2022] Open
Abstract
Oxytocin, acting through the oxytocin receptor (Oxtr) in the periphery, is best known for its roles in regulating parturition and lactation. However, it is also now known to possess a number of important social functions within the central nervous system, including social preference, memory and aggression, that vary to different degrees in different species. The Oxtr is found in both excitatory and inhibitory neurons within the brain and research is focusing on how, for example, activation of the receptor in interneurons can enhance the signal-to-noise of neuronal transmission. It is important to understand which neurons in the mouse dorsal hippocampus might be activated during memory formation. Therefore, we examined the colocalization of transcripts in over 5,000 neurons for Oxtr with those for nine different markers often found in interneurons using hairpin chain reaction in situ hybridization on hippocampal sections. Most pyramidal cell neurons of CA2 and many in the CA3 express Oxtr. Outside of those excitatory neurons, over 90% of Oxtr-expressing neurons co-express glutamic acid decarboxylase-1 (Gad-1) with progressively decreasing numbers of co-expressing cholecystokinin, somatostatin, parvalbumin, neuronal nitric oxide synthase, the serotonin 3a receptor, the vesicular glutamate transporter 3, calbindin 2 (calretinin), and vasoactive intestinal polypeptide neurons. Distributions were analyzed within hippocampal layers and regions as well. These findings indicate that Oxtr activation will modulate the activity of ~30% of the Gad-1 interneurons and the majority of the diverse population of those, mostly, interneuron types specifically examined in the mouse hippocampus.
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Affiliation(s)
- W. Scott Young
- Section on Neural Gene Expression, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States
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27
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Puryear CB, Brooks J, Tan L, Smith K, Li Y, Cunningham J, Todtenkopf MS, Dean RL, Sanchez C. Opioid receptor modulation of neural circuits in depression: What can be learned from preclinical data? Neurosci Biobehav Rev 2020; 108:658-678. [DOI: 10.1016/j.neubiorev.2019.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 12/14/2022]
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Abstract
Although Lorente de No' recognized the anatomical distinction of the hippocampal Cornu Ammonis (CA) 2 region, it had, until recently, been assigned no unique function. Its location between the key players of the circuit, CA3 and CA1, which along with the entorhinal cortex and dentate gyrus compose the classic trisynaptic circuit, further distracted research interest. However, the connectivity of CA2 pyramidal cells, together with unique patterns of gene expression, hints at a much larger contribution to hippocampal information processing than has been ascribed. Here we review recent advances that have identified new roles for CA2 in hippocampal centric processing, together with specialized functions in social memory and, potentially, as a broadcaster of novelty. These new data, together with CA2's role in disease, justify a closer look at how this small region exerts its influence and how it might best be exploited to understand and treat disease-related circuit dysfunctions.
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Affiliation(s)
- Steven J Middleton
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama 351-0198, Japan; ,
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama 351-0198, Japan; ,
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29
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Domínguez S, Rey CC, Therreau L, Fanton A, Massotte D, Verret L, Piskorowski RA, Chevaleyre V. Maturation of PNN and ErbB4 Signaling in Area CA2 during Adolescence Underlies the Emergence of PV Interneuron Plasticity and Social Memory. Cell Rep 2019; 29:1099-1112.e4. [DOI: 10.1016/j.celrep.2019.09.044] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 07/31/2019] [Accepted: 09/13/2019] [Indexed: 12/28/2022] Open
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Leroy F, Brann DH, Meira T, Siegelbaum SA. Input-Timing-Dependent Plasticity in the Hippocampal CA2 Region and Its Potential Role in Social Memory. Neuron 2019; 102:260-262. [PMID: 30946821 DOI: 10.1016/j.neuron.2019.03.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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Routing Hippocampal Information Flow through Parvalbumin Interneuron Plasticity in Area CA2. Cell Rep 2019; 27:86-98.e3. [DOI: 10.1016/j.celrep.2019.03.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 12/12/2018] [Accepted: 03/02/2019] [Indexed: 11/23/2022] Open
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32
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Helton TD, Zhao M, Farris S, Dudek SM. Diversity of dendritic morphology and entorhinal cortex synaptic effectiveness in mouse CA2 pyramidal neurons. Hippocampus 2018; 29:78-92. [PMID: 30067288 DOI: 10.1002/hipo.23012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/09/2018] [Accepted: 07/11/2018] [Indexed: 11/06/2022]
Abstract
Excitatory synaptic inputs from specific brain regions are often targeted to distinct dendritic arbors on hippocampal pyramidal neurons. Recent work has suggested that CA2 pyramidal neurons respond robustly and preferentially to excitatory input into the stratum lacunosum moleculare (SLM), with a relatively modest response to Schaffer collateral excitatory input into stratum radiatum (SR) in acute mouse hippocampal slices, but the extent to which this difference may be explained by morphology is unknown. In an effort to replicate these findings and to better understand the role of dendritic morphology in shaping responses from proximal and distal synaptic sites, we measured excitatory postsynaptic currents and action potentials in CA2 pyramidal cells in response to SR and SLM stimulation and subsequently analyzed confocal images of the filled cells. We found that, in contrast to previous reports, SR stimulation evoked substantial responses in all recorded CA2 pyramidal cells. Strikingly, however, we found that not all neurons responded to SLM stimulation, and in those neurons that did, responses evoked by SLM and SR were comparable in size and effectiveness in inducing action potentials. In a comprehensive morphometric analysis of CA2 pyramidal cell apical dendrites, we found that the neurons that were unresponsive to SLM stimulation were the same ones that lacked substantial apical dendritic arborization in the SLM. Neurons responsive to both SR and SLM stimulation had roughly equal amounts of dendritic branching in each layer. Remarkably, our study in mouse CA2 generally replicates the work characterizing the diversity of CA2 pyramidal cells in the guinea pig hippocampus. We conclude, then, that like in guinea pig, mouse CA2 pyramidal cells have a diverse apical dendrite morphology that is likely to be reflective of both the amount and source of excitatory input into CA2 from the entorhinal cortex and CA3.
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Affiliation(s)
- Thomas D Helton
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Meilan Zhao
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Shannon Farris
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Serena M Dudek
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
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Tirko NN, Eyring KW, Carcea I, Mitre M, Chao MV, Froemke RC, Tsien RW. Oxytocin Transforms Firing Mode of CA2 Hippocampal Neurons. Neuron 2018; 100:593-608.e3. [PMID: 30293821 DOI: 10.1016/j.neuron.2018.09.008] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 01/03/2018] [Accepted: 09/04/2018] [Indexed: 01/30/2023]
Abstract
Oxytocin is an important neuromodulator in the mammalian brain that increases information salience and circuit plasticity, but its signaling mechanisms and circuit effect are not fully understood. Here we report robust oxytocinergic modulation of intrinsic properties and circuit operations in hippocampal area CA2, a region of emerging importance for hippocampal function and social behavior. Upon oxytocin receptor activation, CA2 pyramidal cells depolarize and fire bursts of action potentials, a consequence of phospholipase C signaling to modify two separate voltage-dependent ionic processes. A reduction of potassium current carried by KCNQ-based M channels depolarizes the cell; protein kinase C activity attenuates spike rate of rise and overshoot, dampening after-hyperpolarizations. These actions, in concert with activation of fast-spiking interneurons, promote repetitive firing and CA2 bursting; bursting then governs short-term plasticity of CA2 synaptic transmission onto CA1 and, thus, efficacy of information transfer in the hippocampal network.
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Affiliation(s)
- Natasha N Tirko
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Katherine W Eyring
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Ioana Carcea
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA; Skirball Institute, New York University School of Medicine, New York, NY 10016, USA; Department of Otolaryngology, New York University School of Medicine, New York, NY 10016, USA
| | - Mariela Mitre
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA; Skirball Institute, New York University School of Medicine, New York, NY 10016, USA; Department of Otolaryngology, New York University School of Medicine, New York, NY 10016, USA
| | - Moses V Chao
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA; Skirball Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Robert C Froemke
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA; Skirball Institute, New York University School of Medicine, New York, NY 10016, USA; Department of Otolaryngology, New York University School of Medicine, New York, NY 10016, USA
| | - Richard W Tsien
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA.
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34
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Piskorowski RA, Chevaleyre V. Memory circuits: CA2. Curr Opin Neurobiol 2018; 52:54-59. [DOI: 10.1016/j.conb.2018.04.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/09/2018] [Indexed: 01/01/2023]
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35
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Lovinger DM, Abrahao KP. Synaptic plasticity mechanisms common to learning and alcohol use disorder. ACTA ACUST UNITED AC 2018; 25:425-434. [PMID: 30115764 PMCID: PMC6097767 DOI: 10.1101/lm.046722.117] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/21/2018] [Indexed: 11/24/2022]
Abstract
Alcohol use disorders include drinking problems that span a range from binge drinking to alcohol abuse and dependence. Plastic changes in synaptic efficacy, such as long-term depression and long-term potentiation are widely recognized as mechanisms involved in learning and memory, responses to drugs of abuse, and addiction. In this review, we focus on the effects of chronic ethanol (EtOH) exposure on the induction of synaptic plasticity in different brain regions. We also review findings indicating that synaptic plasticity occurs in vivo during EtOH exposure, with a focus on ex vivo electrophysiological indices of plasticity. Evidence for effects of EtOH-induced or altered synaptic plasticity on learning and memory and EtOH-related behaviors is also reviewed. As this review indicates, there is much work needed to provide more information about the molecular, cellular, circuit, and behavioral consequences of EtOH interactions with synaptic plasticity mechanisms.
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Affiliation(s)
- David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA
| | - Karina P Abrahao
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA
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36
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Carstens KE, Dudek SM. Regulation of synaptic plasticity in hippocampal area CA2. Curr Opin Neurobiol 2018; 54:194-199. [PMID: 30120016 DOI: 10.1016/j.conb.2018.07.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/26/2018] [Accepted: 07/31/2018] [Indexed: 11/15/2022]
Abstract
Synaptic plasticity in the hippocampus is thought to play a vital role in both the refinement of neuronal circuits during development and in learning in the mature brain. Synapses in hippocampal area CA1 are known for a robust capacity for long-term potentiation (LTP), whereas synapses in the stratum radiatum of hippocampal area CA2 are particularly resistant to such changes. Although we have yet to fully understand the mechanisms behind this resistance to plasticity, a number of genes and extracellular matrix components highly expressed in CA2 appear to function as molecular brakes on plasticity and develop postnatally in the rodent brain. Curiously, the developmental profile of several CA2-enriched molecules is suggestive of a still undefined critical window of plasticity in the hippocampus.
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Affiliation(s)
- Kelly E Carstens
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Serena M Dudek
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
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37
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Booker SA, Vida I. Morphological diversity and connectivity of hippocampal interneurons. Cell Tissue Res 2018; 373:619-641. [PMID: 30084021 PMCID: PMC6132631 DOI: 10.1007/s00441-018-2882-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/03/2018] [Indexed: 12/21/2022]
Abstract
The mammalian forebrain is constructed from ensembles of neurons that form local microcircuits giving rise to the exquisite cognitive tasks the mammalian brain can perform. Hippocampal neuronal circuits comprise populations of relatively homogenous excitatory neurons, principal cells and exceedingly heterogeneous inhibitory neurons, the interneurons. Interneurons release GABA from their axon terminals and are capable of controlling excitability in every cellular compartment of principal cells and interneurons alike; thus, they provide a brake on excess activity, control the timing of neuronal discharge and provide modulation of synaptic transmission. The dendritic and axonal morphology of interneurons, as well as their afferent and efferent connections within hippocampal circuits, is central to their ability to differentially control excitability, in a cell-type- and compartment-specific manner. This review aims to provide an up-to-date compendium of described hippocampal interneuron subtypes, with respect to their morphology, connectivity, neurochemistry and physiology, a full understanding of which will in time help to explain the rich diversity of neuronal function.
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Affiliation(s)
- Sam A Booker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK.
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD, UK.
| | - Imre Vida
- Institute for Integrative Neuroanatomy, Charité - Universitätmedizin Berlin, Berlin, Germany.
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38
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Hayani H, Song I, Dityatev A. Increased Excitability and Reduced Excitatory Synaptic Input Into Fast-Spiking CA2 Interneurons After Enzymatic Attenuation of Extracellular Matrix. Front Cell Neurosci 2018; 12:149. [PMID: 29899690 PMCID: PMC5988902 DOI: 10.3389/fncel.2018.00149] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/14/2018] [Indexed: 12/21/2022] Open
Abstract
The neural extracellular matrix (ECM) is enriched with hyaluronic acid, chondroitin sulfate proteoglycans (CSPGs) and the glycoprotein tenascin-R, which play important roles in synaptic plasticity, as shown by studies of the CA1 region of the hippocampus. However, ECM molecules are strongly expressed in the CA2 region, which harbors a high number of fast-spiking interneurons (FSIs) surrounded by a particularly condensed form of ECM, perineuronal nets. Despite this intriguing peculiarity, the functional role of ECM in the CA2 region is mostly unknown. Here, we investigate the acute and delayed effects of chondroitinase ABC (ChABC), an enzyme that digests chondroitin sulfate side chains of CSPGs and greatly attenuates neural ECM, on neuronal excitability and excitatory transmission in the CA2 region. Whole-cell patch clamp recordings of CA2 pyramidal cells (PCs) and FSIs in hippocampal slices revealed that 7 days after injection of ChABC into the CA2 region in vivo, there are alterations in excitability of FSIs and PCs. FSIs generated action potentials with larger amplitudes and longer durations in response to less depolarizing currents compared to controls. PCs were excited at less depolarized membrane potentials, resulted in lower latency of spike generation. The frequency of excitatory postsynaptic currents in FSIs was selectively reduced, while the frequency of inhibitory postsynaptic currents was selectively increased. Acute treatment of hippocampal slices with ChABC did not result in any of these effects. This increase in excitability and changes in synaptic inputs to FSIs after attenuation of ECM suggests a crucial role for perineuronal nets associated with FSIs in regulation of synaptic and electrical properties of these cells.
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Affiliation(s)
- Hussam Hayani
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Inseon Song
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Alexander Dityatev
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany.,Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
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39
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Benoy A, Dasgupta A, Sajikumar S. Hippocampal area CA2: an emerging modulatory gateway in the hippocampal circuit. Exp Brain Res 2018; 236:919-931. [DOI: 10.1007/s00221-018-5187-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Accepted: 01/22/2018] [Indexed: 12/18/2022]
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40
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Hippocampal area CA2: properties and contribution to hippocampal function. Cell Tissue Res 2018; 373:525-540. [PMID: 29335778 DOI: 10.1007/s00441-017-2769-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/07/2017] [Indexed: 12/30/2022]
Abstract
This review focuses on area CA2 of the hippocampus, as recent results have revealed the unique properties and surprising role of this region in encoding social, temporal and contextual aspects of memory. Originally identified and described by Lorente de No, in 1934, this region of the hippocampus has unique intra-and extra-hippocampal connectivity, sending and receiving input to septal and hypothalamic regions. Recent in vivo studies have indicated that CA2 pyramidal neurons encode spatial information during immobility and play an important role in the generation of sharp-wave ripples. Furthermore, CA2 neurons act to control overall excitability in the hippocampal network and have been found to be consistently altered in psychiatric diseases, indicating that normal function of this region is necessary for normal cognition. With its unique role, area CA2 has a unique molecular profile, interneuron density and composition. Furthermore, this region has an unusual manifestation of synaptic plasticity that does not occur post-synaptically at pyramidal neuron dendrities but through the local network of inhibitory neurons. While much progress has recently been made in understanding the large contribution of area CA2 to social memory formation, much still needs to be learned.
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Conditional Deletion of Hippocampal CA2/CA3a Oxytocin Receptors Impairs the Persistence of Long-Term Social Recognition Memory in Mice. J Neurosci 2017; 38:1218-1231. [PMID: 29279308 DOI: 10.1523/jneurosci.1896-17.2017] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/17/2017] [Accepted: 12/18/2017] [Indexed: 11/21/2022] Open
Abstract
Oxytocin (OXT) receptors (OXTRs) are prominently expressed in hippocampal CA2 and CA3 pyramidal neurons, but little is known about its physiological function. As the functional necessity of hippocampal CA2 for social memory processing, we tested whether CA2 OXTRs may contribute to long-term social recognition memory (SRM) formation. Here, we found that conditional deletion of Oxtr from forebrain (Oxtr-/-) or CA2/CA3a-restricted excitatory neurons in adult male mice impaired the persistence of long-term SRM but had no effect on sociability and preference for social novelty. Conditional deletion of CA2/CA3a Oxtr showed no changes in anxiety-like behavior assessed using the open-field, elevated plus maze and novelty-suppressed feeding tests. Application of a highly selective OXTR agonist [Thr4,Gly7]-OXT to hippocampal slices resulted in an acute and lasting potentiation of excitatory synaptic responses in CA2 pyramidal neurons that relied on N-methyl-d-aspartate receptor activation and calcium/calmodulin-dependent protein kinase II activity. In addition, Oxtr-/- mice displayed a defect in the induction of long-term potentiation, but not long-term depression, at the synapses between the entorhinal cortex and CA2 pyramidal neurons. Furthermore, Oxtr deletion led to a reduced complexity of basal dendritic arbors of CA2 pyramidal neurons, but caused no alteration in the density of apical dendritic spines. Considering that the methodologies we have used to delete Oxtr do not rule out targeting the neighboring CA3a region, these findings suggest that OXTR signaling in the CA2/CA3a is crucial for the persistence of long-term SRM.SIGNIFICANCE STATEMENT Oxytocin receptors (OXTRs) are abundantly expressed in hippocampal CA2 and CA3 regions, but there are little known about their physiological function. Taking advantage of the conditional Oxtr knock-out mice, the present study highlights the importance of OXTR signaling in the induction of long-term potentiation at the synapses between the entorhinal cortex and CA2 pyramidal neurons and the persistence of long-term social recognition memory. Thus, OXTRs in the CA2/CA3a may provide a new target for therapeutic approaches to the treatment of social cognition deficits, which are often observed in patients with neuropsychiatric disorders.
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Substance P induces plasticity and synaptic tagging/capture in rat hippocampal area CA2. Proc Natl Acad Sci U S A 2017; 114:E8741-E8749. [PMID: 28973908 DOI: 10.1073/pnas.1711267114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The hippocampal area Cornu Ammonis (CA) CA2 is important for social interaction and is innervated by Substance P (SP)-expressing supramammillary (SuM) nucleus neurons. SP exerts neuromodulatory effects on pain processing and central synaptic transmission. Here we provide evidence that SP can induce a slowly developing NMDA receptor- and protein synthesis-dependent potentiation of synaptic transmission that can be induced not only at entorhinal cortical (EC)-CA2 synapses but also at long-term potentiation (LTP)-resistant Schaffer collateral (SC)-CA2 synapses. In addition, SP-induced potentiation of SC-CA2 synapses transforms a short-term potentiation of EC-CA2 synaptic transmission into LTP, consistent with the synaptic tagging and capture hypothesis. Interestingly, this SP-induced potentiation and associative interaction between the EC and SC inputs of CA2 neurons is independent of the GABAergic system. In addition, CaMKIV and PKMζ play a critical role in the SP-induced effects on SC-CA2 and EC-CA2 synapses. Thus, afferents from SuM neurons are ideally situated to prime CA2 synapses for the formation of long-lasting plasticity and associativity.
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43
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Mancino S, Mendonça-Netto S, Martín-García E, Maldonado R. Role of DOR in neuronal plasticity changes promoted by food-seeking behaviour. Addict Biol 2017; 22:1179-1190. [PMID: 27101941 DOI: 10.1111/adb.12401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/20/2016] [Accepted: 03/15/2016] [Indexed: 12/20/2022]
Abstract
Several lines of evidence support that food overconsumption may be related to the role of the endogenous opioid system in the control of food palatability. The opioid system, and particularly the delta opioid receptor (DOR), plays a crucial role in the regulation of food rewarding properties. In our study, we used operant conditioning maintained by chocolate-flavoured pellets to investigate the role of DOR in the motivation for palatable food and the structural plasticity changes promoted by this behaviour. For this purpose, we evaluated the specific role of this receptor in the behavioural and neuroplastic changes induced by palatable food in the prefrontal cortex (PFC), hippocampus (HCP) and nucleus accumbens (NAc) in constitutive knockout (KO) mice deficient in DOR. Mutant mice and their wild-type littermates were trained to obtain chocolate-flavoured pellets on fixed ratio 1 (FR1), FR5 and progressive ratio (PR) schedule of reinforcement. No significant differences between genotypes were revealed on operant behaviour acquisition in FR1. DOR knockout mice displayed lower number of active lever-presses than wild-type mice on FR5, and a similar decrease was revealed in DOR KO mice in the breaking point during the PR. This operant training to obtain palatable food increased dendritic spine density in the PFC, HCP and NAc shell of wild-type, but these plasticity changes were abolished in DOR KO mice. Our results support the hypothesis that DOR regulates the reinforcing effects and motivation for palatable food through neuroplastic changes in specific brain reward areas.
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Affiliation(s)
- Samantha Mancino
- Laboratori de Neurofarmacologia, Departament de Ciències Experimentals i de la Salut, PRBB; Universitat Pompeu Fabra; Spain
| | - Sueli Mendonça-Netto
- Laboratori de Neurofarmacologia, Departament de Ciències Experimentals i de la Salut, PRBB; Universitat Pompeu Fabra; Spain
| | - Elena Martín-García
- Laboratori de Neurofarmacologia, Departament de Ciències Experimentals i de la Salut, PRBB; Universitat Pompeu Fabra; Spain
| | - Rafael Maldonado
- Laboratori de Neurofarmacologia, Departament de Ciències Experimentals i de la Salut, PRBB; Universitat Pompeu Fabra; Spain
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Leroy F, Brann DH, Meira T, Siegelbaum SA. Input-Timing-Dependent Plasticity in the Hippocampal CA2 Region and Its Potential Role in Social Memory. Neuron 2017; 95:1089-1102.e5. [PMID: 28823730 DOI: 10.1016/j.neuron.2017.07.036] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 05/26/2017] [Accepted: 07/28/2017] [Indexed: 02/01/2023]
Abstract
Input-timing-dependent plasticity (ITDP) is a circuit-based synaptic learning rule by which paired activation of entorhinal cortical (EC) and Schaffer collateral (SC) inputs to hippocampal CA1 pyramidal neurons (PNs) produces a long-term enhancement of SC excitation. We now find that paired stimulation of EC and SC inputs also induces ITDP of SC excitation of CA2 PNs. However, whereas CA1 ITDP results from long-term depression of feedforward inhibition (iLTD) as a result of activation of CB1 endocannabinoid receptors on cholecystokinin-expressing interneurons, CA2 ITDP results from iLTD through activation of δ-opioid receptors on parvalbumin-expressing interneurons. Furthermore, whereas CA1 ITDP has been previously linked to enhanced specificity of contextual memory, we find that CA2 ITDP is associated with enhanced social memory. Thus, ITDP may provide a general synaptic learning rule for distinct forms of hippocampal-dependent memory mediated by distinct hippocampal regions.
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Affiliation(s)
- Felix Leroy
- Department of Neuroscience, Kavli Institute of Brain Science, Columbia University Medical Center, 1051 Riverside Drive, New York, NY, USA.
| | - David H Brann
- Department of Neuroscience, Kavli Institute of Brain Science, Columbia University Medical Center, 1051 Riverside Drive, New York, NY, USA
| | - Torcato Meira
- Department of Neuroscience, Kavli Institute of Brain Science, Columbia University Medical Center, 1051 Riverside Drive, New York, NY, USA; Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Steven A Siegelbaum
- Department of Neuroscience, Kavli Institute of Brain Science, Columbia University Medical Center, 1051 Riverside Drive, New York, NY, USA.
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45
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Ko J. Neuroanatomical Substrates of Rodent Social Behavior: The Medial Prefrontal Cortex and Its Projection Patterns. Front Neural Circuits 2017; 11:41. [PMID: 28659766 PMCID: PMC5468389 DOI: 10.3389/fncir.2017.00041] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 05/29/2017] [Indexed: 12/30/2022] Open
Abstract
Social behavior encompasses a number of distinctive and complex constructs that form the core elements of human imitative culture, mainly represented as either affiliative or antagonistic interactions with conspecifics. Traditionally considered in the realm of psychology, social behavior research has benefited from recent advancements in neuroscience that have accelerated identification of the neural systems, circuits, causative genes and molecular mechanisms that underlie distinct social cognitive traits. In this review article, I summarize recent findings regarding the neuroanatomical substrates of key social behaviors, focusing on results from experiments conducted in rodent models. In particular, I will review the role of the medial prefrontal cortex (mPFC) and downstream subcortical structures in controlling social behavior, and discuss pertinent future research perspectives.
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Affiliation(s)
- Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST)Daegu, South Korea
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46
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Zemla R, Basu J. Hippocampal function in rodents. Curr Opin Neurobiol 2017; 43:187-197. [PMID: 28477511 DOI: 10.1016/j.conb.2017.04.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 04/11/2017] [Accepted: 04/12/2017] [Indexed: 11/16/2022]
Abstract
The hippocampus is crucial for the formation and recall of long-term memories about people, places, objects, and events. Capitalizing on high-resolution microscopy, in vivo electrophysiology, and genetic manipulation, recent research in rodents provides evidence for hippocampal ensemble coding on the spatial, episodic, and contextual dimensions. Here we highlight the functional contribution of newly described long-range connections between hippocampus and cortical areas, and the relative impact of inhibitory and excitatory dynamics in generating behaviorally relevant population activity. Our goal is to provide an integrated view of hippocampal circuit function to understand mnemonic computations at the systems and cellular levels that underlie adaptive learned behaviors.
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Affiliation(s)
- Roland Zemla
- Neuroscience Institute, New York University School of Medicine, USA; Medical Scientist Training Program, New York University School of Medicine, USA
| | - Jayeeta Basu
- Neuroscience Institute, New York University School of Medicine, USA; Department of Neuroscience and Physiology, New York University School of Medicine, USA.
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Rozov AV, Valiullina FF, Bolshakov AP. Mechanisms of long-term plasticity of hippocampal GABAergic synapses. BIOCHEMISTRY (MOSCOW) 2017; 82:257-263. [DOI: 10.1134/s0006297917030038] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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48
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Nasrallah K, Piskorowski RA, Chevaleyre V. Bi-directional interplay between proximal and distal inputs to CA2 pyramidal neurons. Neurobiol Learn Mem 2017; 138:173-181. [DOI: 10.1016/j.nlm.2016.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/22/2016] [Accepted: 06/25/2016] [Indexed: 10/21/2022]
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49
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Oliva A, Fernández-Ruiz A, Buzsáki G, Berényi A. Role of Hippocampal CA2 Region in Triggering Sharp-Wave Ripples. Neuron 2016; 91:1342-1355. [PMID: 27593179 DOI: 10.1016/j.neuron.2016.08.008] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/17/2016] [Accepted: 07/29/2016] [Indexed: 12/20/2022]
Abstract
Sharp-wave ripples (SPW-Rs) in the hippocampus are implied in memory consolidation, as shown by observational and interventional experiments. However, the mechanism of their generation remains unclear. Using two-dimensional silicon probe arrays, we investigated the propagation of SPW-Rs across the hippocampal CA1, CA2, and CA3 subregions. Synchronous activation of CA2 ensembles preceded SPW-R-related population activity in CA3 and CA1 regions. Deep CA2 neurons gradually increased their activity prior to ripples and were suppressed during the population bursts of CA3-CA1 neurons (ramping cells). Activity of superficial CA2 cells preceded the activity surge in CA3-CA1 (phasic cells). The trigger role of the CA2 region in SPW-R was more pronounced during waking than sleeping. These results point to the CA2 region as an initiation zone for SPW-Rs.
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Affiliation(s)
- Azahara Oliva
- MTA-SZTE "Momentum" Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary
| | - Antonio Fernández-Ruiz
- MTA-SZTE "Momentum" Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary; School of Physics, Complutense University, 28040 Madrid, Spain
| | - György Buzsáki
- New York University Neuroscience Institute and Center for Neural Science, New York University, New York, NY 10016, USA.
| | - Antal Berényi
- MTA-SZTE "Momentum" Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary; New York University Neuroscience Institute and Center for Neural Science, New York University, New York, NY 10016, USA.
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50
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Chevaleyre V, Piskorowski RA. Hippocampal Area CA2: An Overlooked but Promising Therapeutic Target. Trends Mol Med 2016; 22:645-655. [DOI: 10.1016/j.molmed.2016.06.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 06/10/2016] [Accepted: 06/10/2016] [Indexed: 10/21/2022]
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