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Park S, Ko SY, Frankland PW, Josselyn SA. Comparing behaviours induced by natural memory retrieval and optogenetic reactivation of an engram ensemble in mice. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230227. [PMID: 38853560 DOI: 10.1098/rstb.2023.0227] [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: 11/14/2023] [Accepted: 04/09/2024] [Indexed: 06/11/2024] Open
Abstract
Memories are thought to be stored within sparse collections of neurons known as engram ensembles. Neurons active during a training episode are allocated to an engram ensemble ('engram neurons'). Memory retrieval is initiated by external sensory or internal cues present at the time of training reactivating engram neurons. Interestingly, optogenetic reactivation of engram ensemble neurons alone in the absence of external sensory cues is sufficient to induce behaviour consistent with memory retrieval in mice. However, there may exist differences between the behaviours induced by natural retrieval cues or artificial engram reactivation. Here, we compared two defensive behaviours (freezing and the syllable structure of ultrasonic vocalizations, USVs) induced by sensory cues present at training (natural memory retrieval) and optogenetic engram ensemble reactivation (artificial memory retrieval) in a threat conditioning paradigm in the same mice. During natural memory recall, we observed a strong positive correlation between freezing levels and distinct USV syllable features (characterized by an unsupervised algorithm, MUPET (Mouse Ultrasonic Profile ExTraction)). Moreover, we observed strikingly similar behavioural profiles in terms of freezing and USV characteristics between natural memory recall and artificial memory recall in the absence of sensory retrieval cues. Although our analysis focused on two behavioural measures of threat memory (freezing and USV characteristics), these results underscore the similarities between threat memory recall triggered naturally and through optogenetic reactivation of engram ensembles. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Sungmo Park
- Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue , Toronto, Ontario M5G 1X8, Canada
| | - Sang Yoon Ko
- Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue , Toronto, Ontario M5G 1X8, Canada
- Department of Physiology, University of Toronto , Toronto, Ontario M5G 1X8, Canada
| | - Paul W Frankland
- Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue , Toronto, Ontario M5G 1X8, Canada
- Department of Physiology, University of Toronto , Toronto, Ontario M5G 1X8, Canada
- Department of Psychology, University of Toronto , Toronto, Ontario M5G 1X8, Canada
| | - Sheena A Josselyn
- Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue , Toronto, Ontario M5G 1X8, Canada
- Department of Physiology, University of Toronto , Toronto, Ontario M5G 1X8, Canada
- Department of Psychology, University of Toronto , Toronto, Ontario M5G 1X8, Canada
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2
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Regele-Blasco E, Palmer LM. The plasticity of pyramidal neurons in the behaving brain. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230231. [PMID: 38853566 DOI: 10.1098/rstb.2023.0231] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 04/23/2024] [Indexed: 06/11/2024] Open
Abstract
Neurons are plastic. That is, they change their activity according to different behavioural conditions. This endows pyramidal neurons with an incredible computational power for the integration and processing of synaptic inputs. Plasticity can be investigated at different levels of investigation within a single neuron, from spines to dendrites, to synaptic input. Although most of our knowledge stems from the in vitro brain slice preparation, plasticity plays a vital role during behaviour by providing a flexible substrate for the execution of appropriate actions in our ever-changing environment. Owing to advances in recording techniques, the plasticity of neurons and the neural networks in which they are embedded is now beginning to be realized in the in vivo intact brain. This review focuses on the structural and functional synaptic plasticity of pyramidal neurons, with a specific focus on the latest developments from in vivo studies. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Elena Regele-Blasco
- The Florey Institute of Neuroscience and Mental Health, The Florey Department of Neuroscience and Mental Health, University of Melbourne , Victoria 3052, Australia
| | - Lucy M Palmer
- The Florey Institute of Neuroscience and Mental Health, The Florey Department of Neuroscience and Mental Health, University of Melbourne , Victoria 3052, Australia
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3
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Abatis M, Perin R, Niu R, van den Burg E, Hegoburu C, Kim R, Okamura M, Bito H, Markram H, Stoop R. Fear learning induces synaptic potentiation between engram neurons in the rat lateral amygdala. Nat Neurosci 2024; 27:1309-1317. [PMID: 38871992 DOI: 10.1038/s41593-024-01676-6] [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: 06/29/2023] [Accepted: 05/07/2024] [Indexed: 06/15/2024]
Abstract
The lateral amygdala (LA) encodes fear memories by potentiating sensory inputs associated with threats and, in the process, recruits 10-30% of its neurons per fear memory engram. However, how the local network within the LA processes this information and whether it also plays a role in storing it are still largely unknown. Here, using ex vivo 12-patch-clamp and in vivo 32-electrode electrophysiological recordings in the LA of fear-conditioned rats, in combination with activity-dependent fluorescent and optogenetic tagging and recall, we identified a sparsely connected network between principal LA neurons that is organized in clusters. Fear conditioning specifically causes potentiation of synaptic connections between learning-recruited neurons. These findings of synaptic plasticity in an autoassociative excitatory network of the LA may suggest a basic principle through which a small number of pyramidal neurons could encode a large number of memories.
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Affiliation(s)
- Marios Abatis
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland
| | - Rodrigo Perin
- Brain-Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ruifang Niu
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland
| | - Erwin van den Burg
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland
| | - Chloe Hegoburu
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland
| | - Ryang Kim
- Department of Neurochemistry, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Michiko Okamura
- Department of Neurochemistry, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Haruhiko Bito
- Department of Neurochemistry, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Henry Markram
- Brain-Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ron Stoop
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland.
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4
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Wang J, Lapate RC. Emotional state dynamics impacts temporal memory. Cogn Emot 2024:1-20. [PMID: 38898587 DOI: 10.1080/02699931.2024.2349326] [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: 02/14/2023] [Accepted: 02/13/2024] [Indexed: 06/21/2024]
Abstract
Emotional fluctuations are ubiquitous in everyday life, but precisely how they sculpt the temporal organisation of memories remains unclear. Here, we designed a novel task - the Emotion Boundary Task - wherein participants viewed sequences of negative and neutral images surrounded by a colour border. We manipulated perceptual context (border colour), emotional-picture valence, as well as the direction of emotional-valence shifts (i.e., shifts from neutral-to-negative and negative-to-neutral events) to create events with a shared perceptual and/or emotional context. We measured memory for temporal order and temporal distances for images processed within and across events. Negative images processed within events were remembered as closer in time compared to neutral ones. In contrast, temporal distances were remembered as longer for images spanning neutral-to-negative shifts - suggesting temporal dilation in memory with the onset of a negative event following a previously-neutral state. The extent of negative-picture induced temporal dilation in memory correlated with dispositional negativity across individuals. Lastly, temporal order memory was enhanced for recently-presented negative (versus neutral) images. These findings suggest that emotional-state dynamics matters when considering emotion-temporal memory interactions: While persistent negative events may compress subjectively remembered time, dynamic shifts from neutral-to-negative events produce temporal dilation in memory, with implications for adaptive emotional functioning.
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Affiliation(s)
- Jingyi Wang
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Regina C Lapate
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, USA
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Brida KL, Jorgensen ET, Phillips RA, Newman CE, Tuscher JJ, Morring EK, Zipperly ME, Ianov L, Montgomery KD, Tippani M, Hyde TM, Maynard KR, Martinowich K, Day JJ. Reelin marks cocaine-activated striatal ensembles, promotes neuronal excitability, and regulates cocaine reward. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599348. [PMID: 38948801 PMCID: PMC11212904 DOI: 10.1101/2024.06.17.599348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Drugs of abuse activate defined neuronal ensembles in brain reward structures such as the nucleus accumbens (NAc), which are thought to promote the enduring synaptic, circuit, and behavioral consequences of drug exposure. While the molecular and cellular effects arising from experience with drugs like cocaine are increasingly well understood, the mechanisms that sculpt NAc ensemble participation are largely unknown. Here, we leveraged unbiased single-nucleus transcriptional profiling to identify expression of the secreted glycoprotein Reelin (encoded by the Reln gene) as a marker of cocaine-activated neuronal ensembles within the rat NAc. Multiplexed in situ detection confirmed selective expression of the immediate early gene Fos in Reln+ neurons after cocaine experience, and also revealed enrichment of Reln mRNA in Drd1 + medium spiny neurons (MSNs) in both the rat and human brain. Using a novel CRISPR interference strategy enabling selective Reln knockdown in the adult NAc, we observed altered expression of genes linked to calcium signaling, emergence of a transcriptional trajectory consistent with loss of cocaine sensitivity, and a striking decrease in MSN intrinsic excitability. At the behavioral level, loss of Reln prevented cocaine locomotor sensitization, abolished cocaine place preference memory, and decreased cocaine self-administration behavior. Together, these results identify Reelin as a critical mechanistic link between ensemble participation and cocaine-induced behavioral adaptations.
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Choucry A, Nomoto M, Inokuchi K. Engram mechanisms of memory linking and identity. Nat Rev Neurosci 2024; 25:375-392. [PMID: 38664582 DOI: 10.1038/s41583-024-00814-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2024] [Indexed: 05/25/2024]
Abstract
Memories are thought to be stored in neuronal ensembles referred to as engrams. Studies have suggested that when two memories occur in quick succession, a proportion of their engrams overlap and the memories become linked (in a process known as prospective linking) while maintaining their individual identities. In this Review, we summarize the key principles of memory linking through engram overlap, as revealed by experimental and modelling studies. We describe evidence of the involvement of synaptic memory substrates, spine clustering and non-linear neuronal capacities in prospective linking, and suggest a dynamic somato-synaptic model, in which memories are shared between neurons yet remain separable through distinct dendritic and synaptic allocation patterns. We also bring into focus retrospective linking, in which memories become associated after encoding via offline reactivation, and discuss key temporal and mechanistic differences between prospective and retrospective linking, as well as the potential differences in their cognitive outcomes.
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Affiliation(s)
- Ali Choucry
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Masanori Nomoto
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
- CREST, Japan Science and Technology Agency (JST), University of Toyama, Toyama, Japan
- Japan Agency for Medical Research and Development (AMED), Tokyo, Japan
| | - Kaoru Inokuchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan.
- CREST, Japan Science and Technology Agency (JST), University of Toyama, Toyama, Japan.
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Zhou Y, Wang JL, Qiu L, Torpey J, Wixson JG, Lyon M, Chen X. NMDA Receptors Control Activity Hierarchy in Neural Network: Loss of Control in Hierarchy Leads to Learning Impairments, Dissociation, and Psychosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.01.06.523038. [PMID: 36712055 PMCID: PMC9881912 DOI: 10.1101/2023.01.06.523038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
While it is known that associative memory is preferentially encoded by memory-eligible "primed" neurons, in vivo neural activity hierarchy has not been quantified and little is known about how such a hierarchy is established. Leveraging in vivo calcium imaging of hippocampal neurons on freely behaving mice, we developed the first method to quantify real-time neural activity hierarchy in the CA1 region. Neurons on the top of activity hierarchy are identified as primed neurons. In cilia knockout mice that exhibit severe learning deficits, the percentage of primed neurons is drastically reduced. We developed a simplified neural network model that incorporates simulations of linear and non-linear weighted components, modeling the synaptic ionic conductance of AMPA and NMDA receptors, respectively. We found that moderate non-linear to linear conductance ratios naturally leads a small fraction of neurons to be primed in the simulated neural network. Removal of the non-linear component eliminates the existing activity hierarchy and reinstate it to the network stochastically primes a new pool of neurons. Blockade of NMDA receptors by ketamine not only decreases general neuronal activity causing learning impairments, but also disrupts neural activity hierarchy. Additionally, ketamine-induced super-synchronized slow oscillation during anesthesia can be simulated if the non-linear NMDAR component is removed to flatten activity hierarchy. Together, this study develops a unique method to measure neural activity hierarchy and identifies NMDA receptors as a key factor that controls the hierarchy. It presents the first evidence suggesting that hierarchy disruption by NMDAR blockade causes dissociation and psychosis.
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Delamare G, Tomé DF, Clopath C. Intrinsic Neural Excitability Biases Allocation and Overlap of Memory Engrams. J Neurosci 2024; 44:e0846232024. [PMID: 38561228 PMCID: PMC11112642 DOI: 10.1523/jneurosci.0846-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 03/25/2024] [Accepted: 03/25/2024] [Indexed: 04/04/2024] Open
Abstract
Memories are thought to be stored in neural ensembles known as engrams that are specifically reactivated during memory recall. Recent studies have found that memory engrams of two events that happened close in time tend to overlap in the hippocampus and the amygdala, and these overlaps have been shown to support memory linking. It has been hypothesized that engram overlaps arise from the mechanisms that regulate memory allocation itself, involving neural excitability, but the exact process remains unclear. Indeed, most theoretical studies focus on synaptic plasticity and little is known about the role of intrinsic plasticity, which could be mediated by neural excitability and serve as a complementary mechanism for forming memory engrams. Here, we developed a rate-based recurrent neural network that includes both synaptic plasticity and neural excitability. We obtained structural and functional overlap of memory engrams for contexts that are presented close in time, consistent with experimental and computational studies. We then investigated the role of excitability in memory allocation at the network level and unveiled competitive mechanisms driven by inhibition. This work suggests mechanisms underlying the role of intrinsic excitability in memory allocation and linking, and yields predictions regarding the formation and the overlap of memory engrams.
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Affiliation(s)
- Geoffroy Delamare
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Douglas Feitosa Tomé
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
| | - Claudia Clopath
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
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Delamare G, Zaki Y, Cai DJ, Clopath C. Drift of neural ensembles driven by slow fluctuations of intrinsic excitability. eLife 2024; 12:RP88053. [PMID: 38712831 DOI: 10.7554/elife.88053] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024] Open
Abstract
Representational drift refers to the dynamic nature of neural representations in the brain despite the behavior being seemingly stable. Although drift has been observed in many different brain regions, the mechanisms underlying it are not known. Since intrinsic neural excitability is suggested to play a key role in regulating memory allocation, fluctuations of excitability could bias the reactivation of previously stored memory ensembles and therefore act as a motor for drift. Here, we propose a rate-based plastic recurrent neural network with slow fluctuations of intrinsic excitability. We first show that subsequent reactivations of a neural ensemble can lead to drift of this ensemble. The model predicts that drift is induced by co-activation of previously active neurons along with neurons with high excitability which leads to remodeling of the recurrent weights. Consistent with previous experimental works, the drifting ensemble is informative about its temporal history. Crucially, we show that the gradual nature of the drift is necessary for decoding temporal information from the activity of the ensemble. Finally, we show that the memory is preserved and can be decoded by an output neuron having plastic synapses with the main region.
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Affiliation(s)
- Geoffroy Delamare
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Yosif Zaki
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Denise J Cai
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Claudia Clopath
- Department of Bioengineering, Imperial College London, London, United Kingdom
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10
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Mocle AJ, Ramsaran AI, Jacob AD, Rashid AJ, Luchetti A, Tran LM, Richards BA, Frankland PW, Josselyn SA. Excitability mediates allocation of pre-configured ensembles to a hippocampal engram supporting contextual conditioned threat in mice. Neuron 2024; 112:1487-1497.e6. [PMID: 38447576 PMCID: PMC11065628 DOI: 10.1016/j.neuron.2024.02.007] [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: 01/24/2022] [Revised: 01/08/2024] [Accepted: 02/05/2024] [Indexed: 03/08/2024]
Abstract
Little is understood about how engrams, sparse groups of neurons that store memories, are formed endogenously. Here, we combined calcium imaging, activity tagging, and optogenetics to examine the role of neuronal excitability and pre-existing functional connectivity on the allocation of mouse cornu ammonis area 1 (CA1) hippocampal neurons to an engram ensemble supporting a contextual threat memory. Engram neurons (high activity during recall or TRAP2-tagged during training) were more active than non-engram neurons 3 h (but not 24 h to 5 days) before training. Consistent with this, optogenetically inhibiting scFLARE2-tagged neurons active in homecage 3 h, but not 24 h, before conditioning disrupted memory retrieval, indicating that neurons with higher pre-training excitability were allocated to the engram. We also observed stable pre-configured functionally connected sub-ensembles of neurons whose activity cycled over days. Sub-ensembles that were more active before training were allocated to the engram, and their functional connectivity increased at training. Therefore, both neuronal excitability and pre-configured functional connectivity mediate allocation to an engram ensemble.
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Affiliation(s)
- Andrew J Mocle
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Adam I Ramsaran
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Alexander D Jacob
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Asim J Rashid
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada
| | - Alessandro Luchetti
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada
| | - Lina M Tran
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada; Vector Institute, Toronto, ON M5G 1M1, Canada
| | | | - Paul W Frankland
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5G 1X8, Canada; Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON M5G 1M1, Canada
| | - Sheena A Josselyn
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5G 1X8, Canada.
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11
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Lopez MR, Wasberg SMH, Gagliardi CM, Normandin ME, Muzzio IA. Mystery of the memory engram: History, current knowledge, and unanswered questions. Neurosci Biobehav Rev 2024; 159:105574. [PMID: 38331127 DOI: 10.1016/j.neubiorev.2024.105574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/22/2023] [Accepted: 02/03/2024] [Indexed: 02/10/2024]
Abstract
The quest to understand the memory engram has intrigued humans for centuries. Recent technological advances, including genetic labelling, imaging, optogenetic and chemogenetic techniques, have propelled the field of memory research forward. These tools have enabled researchers to create and erase memory components. While these innovative techniques have yielded invaluable insights, they often focus on specific elements of the memory trace. Genetic labelling may rely on a particular immediate early gene as a marker of activity, optogenetics may activate or inhibit one specific type of neuron, and imaging may capture activity snapshots in a given brain region at specific times. Yet, memories are multifaceted, involving diverse arrays of neuronal subpopulations, circuits, and regions that work in concert to create, store, and retrieve information. Consideration of contributions of both excitatory and inhibitory neurons, micro and macro circuits across brain regions, the dynamic nature of active ensembles, and representational drift is crucial for a comprehensive understanding of the complex nature of memory.
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Affiliation(s)
- M R Lopez
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
| | - S M H Wasberg
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - C M Gagliardi
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - M E Normandin
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - I A Muzzio
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA.
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12
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Park H, Kaang BK. Memory allocation at the neuronal and synaptic levels. BMB Rep 2024; 57:176-181. [PMID: 37964638 PMCID: PMC11058361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/05/2023] [Accepted: 11/10/2023] [Indexed: 11/16/2023] Open
Abstract
Memory allocation, which determines where memories are stored in specific neurons or synapses, has consistently been demonstrated to occur via specific mechanisms. Neuronal allocation studies have focused on the activated population of neurons and have shown that increased excitability via cAMP response element-binding protein (CREB) induces a bias toward memoryencoding neurons. Synaptic allocation suggests that synaptic tagging enables memory to be mediated through different synaptic strengthening mechanisms, even within a single neuron. In this review, we summarize the fundamental concepts of memory allocation at the neuronal and synaptic levels and discuss their potential interrelationships. [BMB Reports 2024; 57(4): 176-181].
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Affiliation(s)
- HyoJin Park
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science (IBS), Daejeon 34126, Korea
- Department of Biological Science, Seoul National University, Seoul 08826, Korea
| | - Bong-Kiun Kaang
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science (IBS), Daejeon 34126, Korea
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13
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Feng Y, Qin J, Lu Y, Wang M, Wang S, Luo F. Suberoylanilide hydroxamic acid attenuates cognitive impairment in offspring caused by maternal surgery during mid-pregnancy. PLoS One 2024; 19:e0295096. [PMID: 38551911 PMCID: PMC10980197 DOI: 10.1371/journal.pone.0295096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 02/13/2024] [Indexed: 04/01/2024] Open
Abstract
Some pregnant women have to experience non-obstetric surgery during pregnancy under general anesthesia. Our previous studies showed that maternal exposure to sevoflurane, isoflurane, propofol, and ketamine causes cognitive deficits in offspring. Histone acetylation has been implicated in synaptic plasticity. Propofol is commonly used in non-obstetric procedures on pregnant women. Previous studies in our laboratory showed that maternal propofol exposure in pregnancy impairs learning and memory in offspring by disturbing histone acetylation. The present study aims to investigate whether HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) could attenuate learning and memory deficits in offspring caused by maternal surgery under propofol anesthesia during mid-pregnancy. Maternal rats were exposed to propofol or underwent abdominal surgery under propofol anesthesia during middle pregnancy. The learning and memory abilities of the offspring rats were assessed using the Morris water maze (MWM) test. The protein levels of histone deacetylase 2 (HDAC2), phosphorylated cAMP response-element binding (p-CREB), brain-derived neurotrophic factor (BDNF), and phosphorylated tyrosine kinase B (p-TrkB) in the hippocampus of the offspring rats were evaluated by immunofluorescence staining and western blot. Hippocampal neuroapoptosis was detected by TUNEL staining. Our results showed that maternal propofol exposure during middle pregnancy impaired the water-maze learning and memory of the offspring rats, increased the protein level of HDAC2 and reduced the protein levels of p-CREB, BDNF and p-TrkB in the hippocampus of the offspring, and such effects were exacerbated by surgery. SAHA alleviated the cognitive dysfunction and rescued the changes in the protein levels of p-CREB, BDNF and p-TrkB induced by maternal propofol exposure alone or maternal propofol exposure plus surgery. Therefore, SAHA could be a potential and promising agent for treating the learning and memory deficits in offspring caused by maternal nonobstetric surgery under propofol anesthesia.
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Affiliation(s)
- Yunlin Feng
- Center for Rehabilitation Medicine, Department of Anesthesiology, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Department of Anesthesiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Jia Qin
- Center for Rehabilitation Medicine, Department of Anesthesiology, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Yanfei Lu
- Center for Rehabilitation Medicine, Department of Anesthesiology, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Mengdie Wang
- Center for Rehabilitation Medicine, Department of Anesthesiology, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Shengqiang Wang
- Department of Anesthesiology, Yichun People’s Hospital, Yichun, China
| | - Foquan Luo
- Center for Rehabilitation Medicine, Department of Anesthesiology, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
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14
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Wang J, Lapate RC. Emotional state dynamics impacts temporal memory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.25.550412. [PMID: 38464043 PMCID: PMC10925226 DOI: 10.1101/2023.07.25.550412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Emotional fluctuations are ubiquitous in everyday life, but precisely how they sculpt the temporal organization of memories remains unclear. Here, we designed a novel task-the Emotion Boundary Task-wherein participants viewed sequences of negative and neutral images surrounded by a color border. We manipulated perceptual context (border color), emotional valence, as well as the direction of emotional-valence shifts (i.e., shifts from neutral-to-negative and negative-to-neutral events) to create encoding events comprised of image sequences with a shared perceptual and/or emotional context. We measured memory for temporal order and subjectively remembered temporal distances for images processed within and across events. Negative images processed within events were remembered as closer in time compared to neutral ones. In contrast, temporal distance was remembered as longer for images spanning neutral-to-negative shifts-suggesting temporal dilation in memory with the onset of a negative event following a previously-neutral state. The extent of this negative-picture induced temporal dilation in memory correlated with dispositional negativity across individuals. Lastly, temporal order memory was enhanced for recently presented negative (compared to neutral) images. These findings suggest that emotional-state dynamics matters when considering emotion-temporal memory interactions: While persistent negative events may compress subjectively remembered time, dynamic shifts from neutral to negative events produce temporal dilation in memory, which may be relevant for adaptive emotional functioning.
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15
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Leake J, Cardona LS, Mencevski F, Westbrook RF, Holmes NM. Context and Time Regulate Fear Memory Consolidation and Reconsolidation in the Basolateral Amygdala Complex. J Neurosci 2024; 44:e1698232023. [PMID: 38286626 PMCID: PMC10904089 DOI: 10.1523/jneurosci.1698-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 10/31/2023] [Accepted: 11/08/2023] [Indexed: 01/31/2024] Open
Abstract
It is widely accepted that fear memories are consolidated through protein synthesis-dependent changes in the basolateral amygdala complex (BLA). However, recent studies show that protein synthesis is not required to consolidate the memory of a new dangerous experience when it is similar to a prior experience. Here, we examined whether the protein synthesis requirement for consolidating the new experience varies with its spatial and temporal distance from the prior experience. Female and male rats were conditioned to fear a stimulus (S1, e.g., light) paired with shock in stage 1 and a second stimulus (S2, e.g., tone) that preceded additional S1-shock pairings (S2-S1-shock) in stage 2. The latter stage was followed by a BLA infusion of a protein synthesis inhibitor, cycloheximide, or vehicle. Subsequent testing with S2 revealed that protein synthesis in the BLA was not required to consolidate fear to S2 when the training stages occurred 48 h apart in the same context; was required when they were separated by 14 d or occurred in different contexts; but was again not required if S1 was re-presented after the delay or in the different context. Similarly, protein synthesis in the BLA was not required to reconsolidate fear to S2 when the training stages occurred 48 h apart but was required when they occurred 14 d apart. Thus, the protein synthesis requirement for consolidating/reconsolidating fear memories in the BLA is determined by similarity between present and past experiences, the time and place in which they occur, and reminders of the past experiences.
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Affiliation(s)
- Jessica Leake
- School of Psychology, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Luisa Saavedra Cardona
- School of Psychology, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Filip Mencevski
- School of Psychology, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - R Frederick Westbrook
- School of Psychology, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Nathan M Holmes
- School of Psychology, University of New South Wales, Sydney, New South Wales 2052, Australia
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16
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Rajebhosale P, Ananth MR, Kim R, Crouse R, Jiang L, López-Hernández G, Zhong C, Arty C, Wang S, Jone A, Desai NS, Li Y, Picciotto MR, Role LW, Talmage DA. Functionally refined encoding of threat memory by distinct populations of basal forebrain cholinergic projection neurons. eLife 2024; 13:e86581. [PMID: 38363713 DOI: 10.7554/elife.86581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 02/14/2024] [Indexed: 02/18/2024] Open
Abstract
Neurons of the basal forebrain nucleus basalis and posterior substantia innominata (NBM/SIp) comprise the major source of cholinergic input to the basolateral amygdala (BLA). Using a genetically encoded acetylcholine (ACh) sensor in mice, we demonstrate that BLA-projecting cholinergic neurons can 'learn' the association between a naive tone and a foot shock (training) and release ACh in the BLA in response to the conditioned tone 24 hr later (recall). In the NBM/SIp cholinergic neurons express the immediate early gene, Fos following both training and memory recall. Cholinergic neurons that express Fos following memory recall display increased intrinsic excitability. Chemogenetic silencing of these learning-activated cholinergic neurons prevents expression of the defensive behavior to the tone. In contrast, we show that NBM/SIp cholinergic neurons are not activated by an innately threatening stimulus (predator odor). Instead, VP/SIa cholinergic neurons are activated and contribute to defensive behaviors in response to predator odor, an innately threatening stimulus. Taken together, we find that distinct populations of cholinergic neurons are recruited to signal distinct aversive stimuli, demonstrating functionally refined organization of specific types of memory within the cholinergic basal forebrain of mice.
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Affiliation(s)
| | - Mala R Ananth
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, United States
| | - Ronald Kim
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, United States
| | - Richard Crouse
- Yale Interdepartmental Neuroscience Program, Yale University, New Haven, United States
| | - Li Jiang
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, United States
| | | | - Chongbo Zhong
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, United States
| | | | - Shaohua Wang
- National Institute of Environmental Health Sciences, Durham, United States
| | - Alice Jone
- Program in Neuroscience, Stony Brook University, Stony Brook, United States
| | - Niraj S Desai
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, United States
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
- PKU-IDG/McGovern Institute for Brain Research, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Marina R Picciotto
- Yale Interdepartmental Neuroscience Program, Yale University, New Haven, United States
- Department of Psychiatry, Yale University, New Haven, United States
| | - Lorna W Role
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, United States
| | - David A Talmage
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, United States
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17
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Rajebhosale P, Ananth MR, Kim R, Crouse R, Jiang L, López-Hernández G, Zhong C, Arty C, Wang S, Jone A, Desai NS, Li Y, Picciotto MR, Role LW, Talmage DA. Functionally refined encoding of threat memory by distinct populations of basal forebrain cholinergic projection neurons. RESEARCH SQUARE 2024:rs.3.rs-3938016. [PMID: 38405824 PMCID: PMC10889048 DOI: 10.21203/rs.3.rs-3938016/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Neurons of the basal forebrain nucleus basalis and posterior substantia innominata (NBM/SIp) comprise the major source of cholinergic input to the basolateral amygdala (BLA). Using a genetically-encoded acetylcholine (ACh) sensor in mice, we demonstrate that BLA-projecting cholinergic neurons can "learn" the association between a naïve tone and a foot shock (training) and release ACh in the BLA in response to the conditioned tone 24h later (recall). In the NBM/SIp cholinergic neurons express the immediate early gene, Fos following both training and memory recall. Cholinergic neurons that express Fos following memory recall display increased intrinsic excitability. Chemogenetic silencing of these learning-activated cholinergic neurons prevents expression of the defensive behavior to the tone. In contrast, we show that NBM/SIp cholinergic neurons are not activated by an innately threatening stimulus (predator odor). Instead, VP/SIa cholinergic neurons are activated and contribute to defensive behaviors in response to predator odor, an innately threatening stimulus. Taken together, we find that distinct populations of cholinergic neurons are recruited to signal distinct aversive stimuli, demonstrating functionally refined organization of specific types of memory within the cholinergic basal forebrain of mice.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Shaohua Wang
- National Institute of Environmental Health Sciences
| | | | | | - Yulong Li
- Peking University School of Life Sciences
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18
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Jung JH, Wang Y, Rashid AJ, Zhang T, Frankland PW, Josselyn SA. Examining memory linking and generalization using scFLARE2, a temporally precise neuronal activity tagging system. Cell Rep 2023; 42:113592. [PMID: 38103203 PMCID: PMC10842737 DOI: 10.1016/j.celrep.2023.113592] [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: 08/28/2023] [Revised: 10/26/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
How memories are organized in the brain influences whether they are remembered discretely versus linked with other experiences or whether generalized information is applied to entirely novel situations. Here, we used scFLARE2 (single-chain fast light- and activity-regulated expression 2), a temporally precise tagging system, to manipulate mouse lateral amygdala neurons active during one of two 3 min threat experiences occurring close (3 h) or further apart (27 h) in time. Silencing scFLARE2-tagged neurons showed that two threat experiences occurring at distal times are dis-allocated to orthogonal engram ensembles and remembered discretely, whereas the same two threat experiences occurring in close temporal proximity are linked via co-allocation to overlapping engram ensembles. Moreover, we found that co-allocation mediates memory generalization applied to a completely novel stimulus. These results indicate that endogenous temporal evolution of engram ensemble neuronal excitability determines how memories are organized and remembered and that this would not be possible using conventional immediate-early gene-based tagging methods.
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Affiliation(s)
- Jung Hoon Jung
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada
| | - Ying Wang
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Asim J Rashid
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada
| | - Tao Zhang
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada
| | - Paul W Frankland
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada; Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON M5G 1M1, Canada
| | - Sheena A Josselyn
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada.
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19
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Brosens N, Lesuis SL, Rao-Ruiz P, van den Oever MC, Krugers HJ. Shaping Memories Via Stress: A Synaptic Engram Perspective. Biol Psychiatry 2023:S0006-3223(23)01720-1. [PMID: 37977215 DOI: 10.1016/j.biopsych.2023.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 10/09/2023] [Accepted: 11/05/2023] [Indexed: 11/19/2023]
Abstract
Stress modulates the activity of various memory systems and can thereby guide behavioral interaction with the environment in an adaptive or maladaptive manner. At the cellular level, a large body of evidence indicates that (nor)adrenaline and glucocorticoid release induced by acute stress exposure affects synapse function and synaptic plasticity, which are critical substrates for learning and memory. Recent evidence suggests that memories are supported in the brain by sparsely distributed neurons within networks, termed engram cell ensembles. While the physiological and molecular effects of stress on the synapse are increasingly well characterized, how these synaptic modifications shape the multiscale dynamics of engram cell ensembles is still poorly understood. In this review, we discuss and integrate recent information on how acute stress affects synapse function and how this may alter engram cell ensembles and their synaptic connectivity to shape memory strength and memory precision. We provide a mechanistic framework of a synaptic engram under stress and put forward outstanding questions that address knowledge gaps in our understanding of the mechanisms that underlie stress-induced memory modulation.
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Affiliation(s)
- Niek Brosens
- Brain Plasticity Group, Swammerdam Institute for Life Sciences-Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands.
| | - Sylvie L Lesuis
- Brain Plasticity Group, Swammerdam Institute for Life Sciences-Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands; Cellular and Cognitive Neuroscience group, Swammerdam Institute for Life Sciences-Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands
| | - Priyanka Rao-Ruiz
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Michel C van den Oever
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Harm J Krugers
- Brain Plasticity Group, Swammerdam Institute for Life Sciences-Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands.
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20
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Campos B, Choi H, DeMarco AT, Seydell-Greenwald A, Hussain SJ, Joy MT, Turkeltaub PE, Zeiger W. Rethinking Remapping: Circuit Mechanisms of Recovery after Stroke. J Neurosci 2023; 43:7489-7500. [PMID: 37940595 PMCID: PMC10634578 DOI: 10.1523/jneurosci.1425-23.2023] [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: 07/27/2023] [Revised: 08/21/2023] [Accepted: 08/21/2023] [Indexed: 11/10/2023] Open
Abstract
Stroke is one of the most common causes of disability, and there are few treatments that can improve recovery after stroke. Therapeutic development has been hindered because of a lack of understanding of precisely how neural circuits are affected by stroke, and how these circuits change to mediate recovery. Indeed, some of the hypotheses for how the CNS changes to mediate recovery, including remapping, redundancy, and diaschisis, date to more than a century ago. Recent technological advances have enabled the interrogation of neural circuits with ever greater temporal and spatial resolution. These techniques are increasingly being applied across animal models of stroke and to human stroke survivors, and are shedding light on the molecular, structural, and functional changes that neural circuits undergo after stroke. Here we review these studies and highlight important mechanisms that underlie impairment and recovery after stroke. We begin by summarizing knowledge about changes in neural activity that occur in the peri-infarct cortex, specifically considering evidence for the functional remapping hypothesis of recovery. Next, we describe the importance of neural population dynamics, disruptions in these dynamics after stroke, and how allocation of neurons into spared circuits can restore functionality. On a more global scale, we then discuss how effects on long-range pathways, including interhemispheric interactions and corticospinal tract transmission, contribute to post-stroke impairments. Finally, we look forward and consider how a deeper understanding of neural circuit mechanisms of recovery may lead to novel treatments to reduce disability and improve recovery after stroke.
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Affiliation(s)
- Baruc Campos
- Department of Neurology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
| | - Hoseok Choi
- Department of Neurology, Weill Institute for Neuroscience, University of California-San Francisco, San Francisco, California 94158
| | - Andrew T DeMarco
- Center for Brain Plasticity and Recovery, Georgetown University Medical Center, Georgetown University, Washington, DC 20057
- Department of Rehabilitation Medicine, Georgetown University Medical Center, Georgetown University, Washington, DC 20057
| | - Anna Seydell-Greenwald
- Center for Brain Plasticity and Recovery, Georgetown University Medical Center, Georgetown University, Washington, DC 20057
- MedStar National Rehabilitation Hospital, Washington, DC 20010
| | - Sara J Hussain
- Movement and Cognitive Rehabilitation Science Program, Department of Kinesiology and Health Education, University of Texas at Austin, Austin, Texas 78712
| | - Mary T Joy
- The Jackson Laboratory, Bar Harbor, Maine 04609
| | - Peter E Turkeltaub
- Center for Brain Plasticity and Recovery, Georgetown University Medical Center, Georgetown University, Washington, DC 20057
- MedStar National Rehabilitation Hospital, Washington, DC 20010
| | - William Zeiger
- Department of Neurology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
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21
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Sehgal M, Ehlers VE, Moyer JR. Synaptic and intrinsic plasticity within overlapping lateral amygdala ensembles following fear conditioning. Front Cell Neurosci 2023; 17:1221176. [PMID: 37876914 PMCID: PMC10590925 DOI: 10.3389/fncel.2023.1221176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 09/20/2023] [Indexed: 10/26/2023] Open
Abstract
Introduction New learning results in modulation of intrinsic plasticity in the underlying brain regions. Such changes in intrinsic plasticity can influence allocation and encoding of future memories such that new memories encoded during the period of enhanced excitability are linked to the original memory. The temporal window during which the two memories interact depends upon the time course of intrinsic plasticity following new learning. Methods Using the well-characterized lateral amygdala-dependent auditory fear conditioning as a behavioral paradigm, we investigated the time course of changes in intrinsic excitability within lateral amygdala neurons. Results We found transient changes in the intrinsic excitability of amygdala neurons. Neuronal excitability was increased immediately following fear conditioning and persisted for up to 4 days post-learning but was back to naïve levels 10 days following fear conditioning. We also determined the relationship between learning-induced intrinsic and synaptic plasticity. Synaptic plasticity following fear conditioning was evident for up to 24 h but not 4 days later. Importantly, we demonstrated that the enhanced neuronal intrinsic excitability was evident in many of the same neurons that had undergone synaptic plasticity immediately following fear conditioning. Interestingly, such a correlation between synaptic and intrinsic plasticity following fear conditioning was no longer present 24 h post-learning. Discussion These data demonstrate that intrinsic and synaptic changes following fear conditioning are transient and co-localized to the same neurons. Since intrinsic plasticity following fear conditioning is an important determinant for the allocation and consolidation of future amygdala-dependent memories, these findings establish a time course during which fear memories may influence each other.
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Affiliation(s)
- Megha Sehgal
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Vanessa E. Ehlers
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - James R. Moyer
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
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22
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Agetsuma M, Sato I, Tanaka YR, Carrillo-Reid L, Kasai A, Noritake A, Arai Y, Yoshitomo M, Inagaki T, Yukawa H, Hashimoto H, Nabekura J, Nagai T. Activity-dependent organization of prefrontal hub-networks for associative learning and signal transformation. Nat Commun 2023; 14:5996. [PMID: 37803014 PMCID: PMC10558457 DOI: 10.1038/s41467-023-41547-5] [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: 06/18/2022] [Accepted: 09/08/2023] [Indexed: 10/08/2023] Open
Abstract
Associative learning is crucial for adapting to environmental changes. Interactions among neuronal populations involving the dorso-medial prefrontal cortex (dmPFC) are proposed to regulate associative learning, but how these neuronal populations store and process information about the association remains unclear. Here we developed a pipeline for longitudinal two-photon imaging and computational dissection of neural population activities in male mouse dmPFC during fear-conditioning procedures, enabling us to detect learning-dependent changes in the dmPFC network topology. Using regularized regression methods and graphical modeling, we found that fear conditioning drove dmPFC reorganization to generate a neuronal ensemble encoding conditioned responses (CR) characterized by enhanced internal coactivity, functional connectivity, and association with conditioned stimuli (CS). Importantly, neurons strongly responding to unconditioned stimuli during conditioning subsequently became hubs of this novel associative network for the CS-to-CR transformation. Altogether, we demonstrate learning-dependent dynamic modulation of population coding structured on the activity-dependent formation of the hub network within the dmPFC.
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Grants
- MEXT | Japan Society for the Promotion of Science (JSPS)
- This study was supported by the Japan Science and Technology Agency, PRESTO (to M.A.), JSPS KAKENHI Grant (grant number JP18K06536, JP18H05144, JP20H05076, JP21H02801, JP22H05081, JP22H05519 to M.A.; JP20H03357, JP20H05073, JP21K18563 to Y.R.T.; JP20H05065, JP22H05080 to A.K.; JP22H05081 to A.N.), JSPS Bilateral Program (JPJSBP1-20199901 to M.A.), AMED (grant number JP19dm0207086 to M.A.; JP21dm0207117 to H.H.), the grant of Joint Research by the National Institutes of Natural Sciences (NINS program No 01112008 and 01112106 to M.A.), and grants from Brain Science Foundation and Shimadzu Foundation to M.A. and the Takeda Science Foundation to A.K. and H.H. Authors declare that they have no competing interests.
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Affiliation(s)
- Masakazu Agetsuma
- Division of Homeostatic Development, National Institute for Physiological Sciences, 38 Nishigohnaka Myodaiji-cho, Okazaki, Aichi, 444-8585, Japan.
- Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan.
- Division of Molecular Design, Research Center for Systems Immunology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
- Quantum Regenerative and Biomedical Engineering Team, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology (QST), Anagawa 4-9-1, Chiba Inage-ku, Chiba, 263-8555, Japan.
| | - Issei Sato
- Department of Computer Science, Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yasuhiro R Tanaka
- Brain Science Institute, Tamagawa University, 6-1-1 Tamagawagakuen, Machida, Tokyo, 194-8610, Japan
| | - Luis Carrillo-Reid
- Instituto de Neurobiologia, National Autonomous University of Mexico, Boulevard Juriquilla 3001, Juriquilla, Queretaro, CP, 76230, Mexico
| | - Atsushi Kasai
- Graduate School of Pharmaceutical Sciences, Osaka University, Yamadaoka 1-6, Suita, Osaka, 565-0871, Japan
| | - Atsushi Noritake
- Division of Behavioral Development, National Institute for Physiological Sciences, 38 Nishigohnaka Myodaiji-cho, Okazaki, Aichi, 444-8585, Japan
| | - Yoshiyuki Arai
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan
| | - Miki Yoshitomo
- Division of Homeostatic Development, National Institute for Physiological Sciences, 38 Nishigohnaka Myodaiji-cho, Okazaki, Aichi, 444-8585, Japan
| | - Takashi Inagaki
- Division of Homeostatic Development, National Institute for Physiological Sciences, 38 Nishigohnaka Myodaiji-cho, Okazaki, Aichi, 444-8585, Japan
| | - Hiroshi Yukawa
- Quantum Regenerative and Biomedical Engineering Team, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology (QST), Anagawa 4-9-1, Chiba Inage-ku, Chiba, 263-8555, Japan
- Institute of Nano-Life-Systems, Institutes of Innovation for Future Society Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan
| | - Hitoshi Hashimoto
- Graduate School of Pharmaceutical Sciences, Osaka University, Yamadaoka 1-6, Suita, Osaka, 565-0871, Japan
- United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University, and University of Fukui, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Division of Bioscience, Institute for Datability Science, Osaka University, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, 38 Nishigohnaka Myodaiji-cho, Okazaki, Aichi, 444-8585, Japan
| | - Takeharu Nagai
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan
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23
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Carzoli KL, Kogias G, Fawcett-Patel J, Liu SJ. Cerebellar interneurons control fear memory consolidation via learning-induced HCN plasticity. Cell Rep 2023; 42:113057. [PMID: 37656617 PMCID: PMC10616818 DOI: 10.1016/j.celrep.2023.113057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 05/30/2023] [Accepted: 08/15/2023] [Indexed: 09/03/2023] Open
Abstract
While synaptic plasticity is considered the basis of learning and memory, modifications of the intrinsic excitability of neurons can amplify the output of neuronal circuits and consequently change behavior. However, the mechanisms that underlie learning-induced changes in intrinsic excitability during memory formation are poorly understood. In the cerebellum, we find that silencing molecular layer interneurons completely abolishes fear memory, revealing their critical role in memory consolidation. The fear conditioning paradigm produces a lasting reduction in hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in these interneurons. This change increases intrinsic membrane excitability and enhances the response to synaptic stimuli. HCN loss is driven by a decrease in endocannabinoid levels via altered cGMP signaling. In contrast, an increase in release of cerebellar endocannabinoids during memory consolidation abolishes HCN plasticity. Thus, activity in cerebellar interneurons drives fear memory formation via a learning-specific increase in intrinsic excitability, and this process requires the loss of endocannabinoid-HCN signaling.
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Affiliation(s)
- Kathryn Lynn Carzoli
- Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; Southeast Louisiana VA Healthcare System, New Orleans, LA 70119, USA
| | - Georgios Kogias
- Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; Southeast Louisiana VA Healthcare System, New Orleans, LA 70119, USA
| | - Jessica Fawcett-Patel
- Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; Southeast Louisiana VA Healthcare System, New Orleans, LA 70119, USA
| | - Siqiong June Liu
- Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; Southeast Louisiana VA Healthcare System, New Orleans, LA 70119, USA.
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24
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Fang X, Alsbury-Nealy B, Wang Y, Frankland PW, Josselyn SA, Schlichting ML, Duncan KD. Time separating spatial memories does not influence their integration in humans. PLoS One 2023; 18:e0289649. [PMID: 37561677 PMCID: PMC10414573 DOI: 10.1371/journal.pone.0289649] [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: 12/24/2022] [Accepted: 07/23/2023] [Indexed: 08/12/2023] Open
Abstract
Humans can navigate through similar environments-like grocery stores-by integrating across their memories to extract commonalities or by differentiating between each to find idiosyncratic locations. Here, we investigate one factor that might impact whether two related spatial memories are integrated or differentiated: Namely, the temporal delay between experiences. Rodents have been shown to integrate memories more often when they are formed within 6 hours of each other. To test if this effect influences how humans spontaneously integrate spatial memories, we had 131 participants search for rewards in two similar virtual environments. We separated these learning experiences by either 30 minutes, 3 hours, or 27 hours. Memory integration was assessed three days later. Participants were able to integrate and simultaneously differentiate related memories across experiences. However, neither memory integration nor differentiation was modulated by temporal delay, in contrast to previous work. We further showed that both the levels of initial memory reactivation during the second experience and memory generalization to novel environments were comparable across conditions. Moreover, perseveration toward the initial reward locations during the second experience was related positively to integration and negatively to differentiation-but again, these associations did not vary by delay. Our findings identify important boundary conditions on the translation of rodent memory mechanisms to humans, motivating more research to characterize how even fundamental memory mechanisms are conserved and diverge across species.
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Affiliation(s)
- Xiaoping Fang
- Department of Psychology, University of Toronto, Toronto, Canada
- School of Psychology, Beijing Language and Culture University, Beijing, China
| | | | - Ying Wang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
| | - Paul W. Frankland
- Department of Psychology, University of Toronto, Toronto, Canada
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada
| | - Sheena A. Josselyn
- Department of Psychology, University of Toronto, Toronto, Canada
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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Guskjolen A, Cembrowski MS. Engram neurons: Encoding, consolidation, retrieval, and forgetting of memory. Mol Psychiatry 2023; 28:3207-3219. [PMID: 37369721 PMCID: PMC10618102 DOI: 10.1038/s41380-023-02137-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 06/02/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023]
Abstract
Tremendous strides have been made in our understanding of the neurobiological substrates of memory - the so-called memory "engram". Here, we integrate recent progress in the engram field to illustrate how engram neurons transform across the "lifespan" of a memory - from initial memory encoding, to consolidation and retrieval, and ultimately to forgetting. To do so, we first describe how cell-intrinsic properties shape the initial emergence of the engram at memory encoding. Second, we highlight how these encoding neurons preferentially participate in synaptic- and systems-level consolidation of memory. Third, we describe how these changes during encoding and consolidation guide neural reactivation during retrieval, and facilitate memory recall. Fourth, we describe neurobiological mechanisms of forgetting, and how these mechanisms can counteract engram properties established during memory encoding, consolidation, and retrieval. Motivated by recent experimental results across these four sections, we conclude by proposing some conceptual extensions to the traditional view of the engram, including broadening the view of cell-type participation within engrams and across memory stages. In collection, our review synthesizes general principles of the engram across memory stages, and describes future avenues to further understand the dynamic engram.
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Affiliation(s)
- Axel Guskjolen
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.
| | - Mark S Cembrowski
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada.
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada.
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Zhuo Z, Wang Y, Kong H, Fu T. GKLF, a transcriptional activator of Txnip, drives microglia activation in kainic acid-induced murine models of epileptic seizures. Int Immunopharmacol 2023; 121:110426. [PMID: 37295029 DOI: 10.1016/j.intimp.2023.110426] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 05/22/2023] [Accepted: 05/30/2023] [Indexed: 06/11/2023]
Abstract
Neuroinflammation is a major component of epilepsy. Gut-enriched Kruppel-like factor (GKLF), a transcription factor of Kruppel-like factor family, has been reported to promote microglia activation and mediate neuroinflammation. However, the role of GKLF in epilepsy remains poorly characterized. This study focused on the function of GKLF in neuron loss and neuroinflammation in epilepsy and the molecular mechanism underlying microglia activation induced by GKLF upon lipopolysaccharides (LPS) treatment. An experimental epileptic model was induced by an intraperitoneal injection of 25 mg/kg kainic acid (KA). Lentivirus vectors (Lv) carrying Gklf CDS or short hairpin RNA targeting Gklf (shGKLF) was injected into the hippocampus, resulting in Gklf overexpression or knockdown in the hippocampus. BV-2 cells were co-infected with Lv-shGKLF or/and Lv carrying thioredoxin interacting protein (Txnip) CDS for 48 h and treated with 1 μg/mL LPS for 24 h. Results showed that GKLF enhanced KA-induced neuronal loss, pro-inflammatory cytokine secretion, activation of NOD-like receptor protein-3 (NLRP3) inflammasomes and microglia, and TXNIP expression in the hippocampus. GKLF inhibition showed negative effects on LPS-induced microglia activation, as evidenced by reduced pro-inflammatory cytokine secretion and activation of NLRP3 inflammasomes. GKLF bound to Txnip promoter and increased TXNIP expression in LPS-activated microglia. Interestingly, Txnip overexpression reversed the inhibitory effect of Gklf knockdown on microglia activation. These findings indicated that GKLF was involved in microglia activation via TXNIP. This study demonstrates the underlying mechanism of GKLF in the pathogenesis of epilepsy and uncovers that GKLF inhibition may be a therapeutic strategy for epilepsy treatment.
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Affiliation(s)
- Zhihong Zhuo
- Department of Pediatrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China.
| | - Yao Wang
- Department of Pediatrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Huimin Kong
- Department of Pediatrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Tianjiao Fu
- Department of Pediatrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
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27
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Brunswick CA, Baldwin DJ, Bodinayake KK, McKenna AR, Lo CY, Bellfy L, Urban MW, Stuart EM, Murakami S, Smies CW, Kwapis JL. The clock gene Per1 is necessary in the retrosplenial cortex-but not in the suprachiasmatic nucleus-for incidental learning in young and aging male mice. Neurobiol Aging 2023; 126:77-90. [PMID: 36958103 PMCID: PMC10106450 DOI: 10.1016/j.neurobiolaging.2023.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/03/2023] [Accepted: 02/18/2023] [Indexed: 02/24/2023]
Abstract
Aging impairs both circadian rhythms and memory, though the relationship between these impairments is not fully understood. Circadian rhythms are largely dictated by clock genes within the body's central pacemaker, the suprachiasmatic nucleus (SCN), though these genes are also expressed in local clocks throughout the body. As circadian rhythms can directly affect memory performance, one possibility is that memory deficits observed with age are downstream of global circadian rhythm disruptions stemming from the SCN. Here, we demonstrate that expression of clock gene Period1 within a memory-relevant cortical structure, the retrosplenial cortex (RSC), is necessary for incidental learning, and that age-related disruption of Period1 within the RSC-but not necessarily the SCN-contributes to cognitive decline. These data expand the known functions of clock genes beyond maintaining circadian rhythms and suggests that age-associated changes in clock gene expression modulates circadian rhythms and memory performance in a brain region-dependent manner.
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Affiliation(s)
- Chad A Brunswick
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Derek J Baldwin
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Kasuni K Bodinayake
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA
| | | | - Chen-Yu Lo
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Lauren Bellfy
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Mark W Urban
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Emily M Stuart
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Shoko Murakami
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Chad W Smies
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Janine L Kwapis
- Department of Biology, Pennsylvania State University, University Park, PA.
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28
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Malakasis N, Chavlis S, Poirazi P. Synaptic turnover promotes efficient learning in bio-realistic spiking neural networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541722. [PMID: 37292929 PMCID: PMC10245885 DOI: 10.1101/2023.05.22.541722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
While artificial machine learning systems achieve superhuman performance in specific tasks such as language processing, image and video recognition, they do so use extremely large datasets and huge amounts of power. On the other hand, the brain remains superior in several cognitively challenging tasks while operating with the energy of a small lightbulb. We use a biologically constrained spiking neural network model to explore how the neural tissue achieves such high efficiency and assess its learning capacity on discrimination tasks. We found that synaptic turnover, a form of structural plasticity, which is the ability of the brain to form and eliminate synapses continuously, increases both the speed and the performance of our network on all tasks tested. Moreover, it allows accurate learning using a smaller number of examples. Importantly, these improvements are most significant under conditions of resource scarcity, such as when the number of trainable parameters is halved and when the task difficulty is increased. Our findings provide new insights into the mechanisms that underlie efficient learning in the brain and can inspire the development of more efficient and flexible machine learning algorithms.
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Affiliation(s)
- Nikos Malakasis
- School of Medicine, University of Crete, Heraklion 70013, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion 70013, Greece
| | - Spyridon Chavlis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion 70013, Greece
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion 70013, Greece
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29
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Park A, Jacob AD, Hsiang HLL, Frankland PW, Howland JG, Josselyn SA. Formation and fate of an engram in the lateral amygdala supporting a rewarding memory in mice. Neuropsychopharmacology 2023; 48:724-733. [PMID: 36261624 PMCID: PMC10066178 DOI: 10.1038/s41386-022-01472-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 09/27/2022] [Accepted: 10/01/2022] [Indexed: 11/08/2022]
Abstract
Memories allow past experiences to guide future decision making and behavior. Sparse ensembles of neurons, known as engrams, are thought to store memories in the brain. Most previous research has focused on engrams supporting threatening or fearful memories where results show that neurons involved in a particular engram ("engram neurons") are both necessary and sufficient for memory expression. Far less is understood about engrams supporting appetitive or rewarding memories. As circumstances and environments are dynamic, the fate of a previously acquired engram with changing circumstances is unknown. Here we examined how engrams supporting a rewarding cue-cocaine memory are formed and whether this original engram is important in reinstatement of memory-guided behavior following extinction. Using a variety of techniques, we show that neurons in the lateral amygdala are allocated to an engram based on relative neuronal excitability at training. Furthermore, once allocated, these neurons become both necessary and sufficient for behavior consistent with recall of that rewarding memory. Allocated neurons are also critical for cocaine-primed reinstatement of memory-guided behavior following extinction. Moreover, artificial reactivation of initially allocated neurons supports reinstatement-like behavior following extinction even in the absence of cocaine-priming. Together, these findings suggest that cocaine priming after extinction reactivates the original engram, and that memory-guided reinstatement behavior does not occur in the absence of this reactivation. Although we focused on neurons in one brain region only, our findings that manipulations of lateral amygdala engram neurons alone were sufficient to impact memory-guided behavior indicate that the lateral amygdala is a critical hub region in what may be a larger brain-wide engram.
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Affiliation(s)
- Albert Park
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
| | - Alexander D Jacob
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
- Department of Psychology, University of Toronto, Toronto, ON, M5G 1X8, Canada
| | - Hwa-Lin Liz Hsiang
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
| | - Paul W Frankland
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
- Department of Psychology, University of Toronto, Toronto, ON, M5G 1X8, Canada
- Department of Physiology, University of Toronto, Toronto, ON, M5G 1X8, Canada
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON, M5G 1M1, Canada
| | - John G Howland
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada.
| | - Sheena A Josselyn
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada.
- Department of Psychology, University of Toronto, Toronto, ON, M5G 1X8, Canada.
- Department of Physiology, University of Toronto, Toronto, ON, M5G 1X8, Canada.
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30
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de Andrade CV, Soliani AG, Cerutti SM. Standardized extract of Ginkgo biloba treatment and novelty on the weak encoding of spatial recognition memory in rats. Learn Mem 2023; 30:85-95. [PMID: 37072140 PMCID: PMC10165992 DOI: 10.1101/lm.053755.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 03/21/2023] [Indexed: 04/20/2023]
Abstract
Long-term memory (LTM) formation is dependent on neurochemical changes that guarantee that a recently formed memory (short-term memory [STM]) remains in the specific neural circuitry via the consolidation process. The persistence of recognition memory has been evidenced by using behavioral tagging in young adult rats, but it has not been effective on aging. Here, we investigated the effects of treatment with a standardized extract of Ginkgo biloba (EGb) associated with novelty on the consolidation of object location memory (OLM) and its persistence after weak training of spatial object preference in young adult and aged rats. The object location task used in this study included two habituation sessions, training sessions associated or not associated with EGb treatment and contextual novelty, and short-term or long-term retention testing sessions. Altogether, our data showed that treatment with EGb associated with novelty close to the time of encoding resulted in STM that lasted for 1 h and persisted for 24 h for both young adult and aged rats. In aged rats, the cooperative mechanisms induced robust long-term OLM. Our findings support and extend our knowledge about recognition memory in aged rats and the modulating effects of EGb treatment and contextual novelty on the persistence of memory.
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Affiliation(s)
- Carla Vitor de Andrade
- The Graduate Program in Structural and Functional Biology, Universidade Federal de São Paulo, São Paulo 09972-270, Brazil
- Cellular and Behavioral Pharmacology Laboratory, Department of Biological Science, Universidade Federal de São Paulo, São Paulo 09972-270, Brazil
| | - Andressa Gabriela Soliani
- Cellular and Behavioral Pharmacology Laboratory, Department of Biological Science, Universidade Federal de São Paulo, São Paulo 09972-270, Brazil
- the Graduate Program in Chemical Biology, Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, São Paulo 09972-270, Brazil
| | - Suzete Maria Cerutti
- The Graduate Program in Structural and Functional Biology, Universidade Federal de São Paulo, São Paulo 09972-270, Brazil
- Cellular and Behavioral Pharmacology Laboratory, Department of Biological Science, Universidade Federal de São Paulo, São Paulo 09972-270, Brazil
- the Graduate Program in Chemical Biology, Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, São Paulo 09972-270, Brazil
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31
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Heritable Risk and Protective Genetic Components of Glaucoma Medication Non-Adherence. Int J Mol Sci 2023; 24:ijms24065636. [PMID: 36982708 PMCID: PMC10058353 DOI: 10.3390/ijms24065636] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 03/18/2023] Open
Abstract
Glaucoma is the leading cause of irreversible blindness, affecting 76 million globally. It is characterized by irreversible damage to the optic nerve. Pharmacotherapy manages intraocular pressure (IOP) and slows disease progression. However, non-adherence to glaucoma medications remains problematic, with 41–71% of patients being non-adherent to their prescribed medication. Despite substantial investment in research, clinical effort, and patient education protocols, non-adherence remains high. Therefore, we aimed to determine if there is a substantive genetic component behind patients’ glaucoma medication non-adherence. We assessed glaucoma medication non-adherence with prescription refill data from the Marshfield Clinic Healthcare System’s pharmacy dispensing database. Two standard measures were calculated: the medication possession ratio (MPR) and the proportion of days covered (PDC). Non-adherence on each metric was defined as less than 80% medication coverage over 12 months. Genotyping was done using the Illumina HumanCoreExome BeadChip in addition to exome sequencing on the 230 patients (1) to calculate the heritability of glaucoma medication non-adherence and (2) to identify SNPs and/or coding variants in genes associated with medication non-adherence. Ingenuity pathway analysis (IPA) was utilized to derive biological meaning from any significant genes in aggregate. Over 12 months, 59% of patients were found to be non-adherent as measured by the MPR80, and 67% were non-adherent as measured by the PDC80. Genome-wide complex trait analysis (GCTA) suggested that 57% (MPR80) and 48% (PDC80) of glaucoma medication non-adherence could be attributed to a genetic component. Missense mutations in TTC28, KIAA1731, ADAMTS5, OR2W3, OR10A6, SAXO2, KCTD18, CHCHD6, and UPK1A were all found to be significantly associated with glaucoma medication non-adherence by whole exome sequencing after Bonferroni correction (p < 10−3) (PDC80). While missense mutations in TINAG, CHCHD6, GSTZ1, and SEMA4G were found to be significantly associated with medication non-adherence by whole exome sequencing after Bonferroni correction (p < 10−3) (MPR80). The same coding SNP in CHCHD6 which functions in Alzheimer’s disease pathophysiology was significant by both measures and increased risk for glaucoma medication non-adherence by three-fold (95% CI, 1.62–5.8). Although our study was underpowered for genome-wide significance, SNP rs6474264 within ZMAT4 (p = 5.54 × 10–6) was found to be nominally significant, with a decreased risk for glaucoma medication non-adherence (OR, 0.22; 95% CI, 0.11–0.42)). IPA demonstrated significant overlap, utilizing, both standard measures including opioid signaling, drug metabolism, and synaptogenesis signaling. CREB signaling in neurons (which is associated with enhancing the baseline firing rate for the formation of long-term potentiation in nerve fibers) was shown to have protective associations. Our results suggest a substantial heritable genetic component to glaucoma medication non-adherence (47–58%). This finding is in line with genetic studies of other conditions with a psychiatric component (e.g., post-traumatic stress disorder (PTSD) or alcohol dependence). Our findings suggest both risk and protective statistically significant genes/pathways underlying glaucoma medication non-adherence for the first time. Further studies investigating more diverse populations with larger sample sizes are needed to validate these findings.
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Chen L, Francisco TR, Baggetta AM, Zaki Y, Ramirez S, Clem RL, Shuman T, Cai DJ. Ensemble-specific deficit in neuronal intrinsic excitability in aged mice. Neurobiol Aging 2023; 123:92-97. [PMID: 36652783 PMCID: PMC9892234 DOI: 10.1016/j.neurobiolaging.2022.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
With the prevalence of age-related cognitive deficits on the rise, it is essential to identify cellular and circuit alterations that contribute to age-related memory impairment. Increased intrinsic neuronal excitability after learning is important for memory consolidation, and changes to this process could underlie memory impairment in old age. Some studies find age-related deficits in hippocampal neuronal excitability that correlate with memory impairment but others do not, possibly due to selective changes only in activated neural ensembles. Thus, we tagged CA1 neurons activated during learning and recorded their intrinsic excitability 5 hours or 7 days post-training. Adult mice exhibited increased neuronal excitability 5 hours after learning, specifically in ensemble (learning-activated) CA1 neurons. As expected, ensemble excitability returned to baseline 7 days post-training. In aged mice, there was no ensemble-specific excitability increase after learning, which was associated with impaired hippocampal memory performance. These results suggest that CA1 may be susceptible to age-related impairments in post-learning ensemble excitability and underscore the need to selectively measure ensemble-specific changes in the brain.
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Affiliation(s)
- Lingxuan Chen
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Taylor R Francisco
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Austin M Baggetta
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yosif Zaki
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Steve Ramirez
- Psychological and Brain Sciences, Boston University, Boston, MA, USA
| | - Roger L Clem
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Tristan Shuman
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Denise J Cai
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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Inactivation of the dorsal CA1 hippocampus impairs the consolidation of discriminative avoidance memory by modulating the intrinsic and extrinsic hippocampal circuitry. J Chem Neuroanat 2023; 128:102209. [PMID: 36496001 DOI: 10.1016/j.jchemneu.2022.102209] [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: 09/09/2022] [Revised: 12/04/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
Despite progress in understanding the role of the dorsal hippocampus in the acquisition, consolidation and retrieval of episodic-like memory, plastic changes within the intra- and extrahippocampal circuits for aversive memory formation and anxiety-like behaviours must still be identified since both processes contribute to multiple aspects of flexible decision-making. Here, we investigated the effect of reversible inactivation induced by a muscimol microinfusion into the dorsal CA1 subfield (dCA1) either prior to acquisition or to retrieval testing of a discriminative avoidance task performed in a plus-maze apparatus (PM-DAT). Differential cAMP-response-element-binding protein 1 (CREB-1) expression in the dorsal and ventral CA1 and CA3 of the hippocampus (dCA1, dCA3, vCA1, and vCA3), dorsal dentate gyrus (dDG), and infralimbic (IL) and prelimbic (PrL) regions of the medial prefrontal cortex was also assessed to investigate the molecular changes associated with the consolidation or retrieval of episodic-like memory and anxiety. Adult male Wistar rats were assigned to two control groups, learning (no surgery/no microinfusion, n = 7) and sham-operated (sham surgery/no microinfusion, n = 6) groups, or four experimental groups, in which the vehicle (0.5 µl per side, n = 8/per group) or a GABAA receptor agonist (0.5 µg/0.5 µl muscimol/per side) was bilaterally microinfused in the dCA1 30 min prior to training (n = 9) or prior to testing sessions (n = 6) with a 24 h intertrial interval. Memory was evaluated using the percentage of time spent in the nonaversive enclosed arms, whereas anxiety was measured by calculating the percentages of time spent and entries into open arms and the percentage of time spent self-grooming. Our findings corroborated previous data showing that the dCA1 is required for discriminative avoidance consolidation. Furthermore, additional information indicated that impaired long-term memory was associated with downregulated CREB-1 expression in the dDG and vCA3. Moreover, memory retrieval was not impaired by dCA1 inactivation prior to the testing session, which was associated with the upregulation of CREB-1 in the dCA3 and vCA1 and downregulation in the dCA1 and vCA3. Differential expression of CREB was not identified in the IL or PrL areas. These results improve our understanding of how the hippocampal circuitry mediates the acquisition and retrieval of aversive memory and anxiety.
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Santos TB, Kramer-Soares JC, Oliveira MGM. Contextual fear conditioning with a time interval induces CREB phosphorylation in the dorsal hippocampus and amygdala nuclei that depend on prelimbic cortex activity. Hippocampus 2023. [PMID: 36847108 DOI: 10.1002/hipo.23516] [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: 10/17/2022] [Revised: 01/20/2023] [Accepted: 02/03/2023] [Indexed: 03/01/2023]
Abstract
In temporal associations, a conditioned stimulus (CS) is separated by a time interval from the unconditioned stimulus (US), which activates the prelimbic cortex (PL) to maintain a CS representation over time. However, it is unknown whether the PL participates, besides the encoding, in the memory consolidation, and thus directly, with activity-dependent changes or indirectly, by modulation of activity-dependent changes in other brain regions. We investigated brain regions supporting the consolidation of associations with intervals and the influence of PL activity in this consolidation process. For this, we observed in Wistar rats the effect of pre-training PL inactivation by muscimol in CREB (cAMP response element-binding protein) phosphorylation, which is essential for memory consolidation, in subdivisions of the medial prefrontal cortex (mPFC), hippocampus, and amygdala 3 h after the training in the contextual fear conditioning (CFC) or CFC with 5-s interval (CFC-5s), fear associations without or with an interval between the CS and US, respectively. Both the CFC-5s and CFC training increased phosphorylation of CREB in the PL and infralimbic cortex (IL); lateral (LA) and basolateral (BLA) amygdala; dorsal CA1 (dCA1); dorsal (dDG), and ventral dentate gyrus, and the CFC-5s training in the central amygdala (CEA). PL activity was necessary for the CREB phosphorylation in the PL, BLA, CEA, dCA1, and dDG only in animals trained in the CFC-5s. The cingulate cortex, ventral CA1, and ventral subiculum did not have learning-induced phosphorylation of CREB. These results suggest that the mPFC, hippocampus, and amygdala support the consolidation of associations with or without intervals and that PL activity influences consolidation in the dorsal hippocampus and amygdala in temporal associations. Thereby, the PL contributes directly and indirectly by modulation to memory consolidation. The time interval engaged the PL early in recent memory consolidation. Results expanded PL's role beyond the time interval and remote memory consolidation.
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Affiliation(s)
- Thays Brenner Santos
- Departamento de Psicobiologia, Universidade Federal de São Paulo - UNIFESP, São Paulo, Brazil
| | - Juliana Carlota Kramer-Soares
- Departamento de Psicobiologia, Universidade Federal de São Paulo - UNIFESP, São Paulo, Brazil.,Universidade Cruzeiro do Sul - UNICSUL, São Paulo, Brazil
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35
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Memory travels through cells backward. Neuron 2023; 111:445-447. [PMID: 36796324 DOI: 10.1016/j.neuron.2023.01.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Can memory ensembles recruit neurons in connected brain regions? In this issue of Neuron, Lavi et al.1 drove the allocation of memory to selected cells in one area, causing their presynaptic partners to become part of a cross-regional ensemble.
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36
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Grochowska KM, Gomes GM, Raman R, Kaushik R, Sosulina L, Kaneko H, Oelschlegel AM, Yuanxiang P, Reyes‐Resina I, Bayraktar G, Samer S, Spilker C, Woo MS, Morawski M, Goldschmidt J, Friese MA, Rossner S, Navarro G, Remy S, Reissner C, Karpova A, Kreutz MR. Jacob-induced transcriptional inactivation of CREB promotes Aβ-induced synapse loss in Alzheimer's disease. EMBO J 2023; 42:e112453. [PMID: 36594364 PMCID: PMC9929644 DOI: 10.15252/embj.2022112453] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 01/04/2023] Open
Abstract
Synaptic dysfunction caused by soluble β-amyloid peptide (Aβ) is a hallmark of early-stage Alzheimer's disease (AD), and is tightly linked to cognitive decline. By yet unknown mechanisms, Aβ suppresses the transcriptional activity of cAMP-responsive element-binding protein (CREB), a master regulator of cell survival and plasticity-related gene expression. Here, we report that Aβ elicits nucleocytoplasmic trafficking of Jacob, a protein that connects a NMDA-receptor-derived signalosome to CREB, in AD patient brains and mouse hippocampal neurons. Aβ-regulated trafficking of Jacob induces transcriptional inactivation of CREB leading to impairment and loss of synapses in mouse models of AD. The small chemical compound Nitarsone selectively hinders the assembly of a Jacob/LIM-only 4 (LMO4)/ Protein phosphatase 1 (PP1) signalosome and thereby restores CREB transcriptional activity. Nitarsone prevents impairment of synaptic plasticity as well as cognitive decline in mouse models of AD. Collectively, the data suggest targeting Jacob protein-induced CREB shutoff as a therapeutic avenue against early synaptic dysfunction in AD.
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Affiliation(s)
- Katarzyna M Grochowska
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Leibniz Group ‘Dendritic Organelles and Synaptic Function’, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Guilherme M Gomes
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
| | - Rajeev Raman
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Rahul Kaushik
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Liudmila Sosulina
- Department of Cellular NeuroscienceLeibniz Institute for NeurobiologyMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Hiroshi Kaneko
- Department of Cellular NeuroscienceLeibniz Institute for NeurobiologyMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | | | - PingAn Yuanxiang
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | | | - Gonca Bayraktar
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Sebastian Samer
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Christina Spilker
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Marcel S Woo
- Institute of Neuroimmunology and Multiple Sclerosis, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Markus Morawski
- Molecular Imaging in NeurosciencesPaul Flechsig Institute of Brain ResearchLeipzigGermany
| | - Jürgen Goldschmidt
- Department of Systems Physiology of Learning and MemoryLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Manuel A Friese
- Institute of Neuroimmunology and Multiple Sclerosis, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Steffen Rossner
- Molecular Imaging in NeurosciencesPaul Flechsig Institute of Brain ResearchLeipzigGermany
| | - Gemma Navarro
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food ScienceUniversity of BarcelonaBarcelonaSpain
- Institut de Neurociències de la Universitat de BarcelonaBarcelonaSpain
| | - Stefan Remy
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
- Department of Cellular NeuroscienceLeibniz Institute for NeurobiologyMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Carsten Reissner
- Institute of Anatomy and Molecular NeurobiologyWestfälische Wilhelms‐UniversityMünsterGermany
| | - Anna Karpova
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
| | - Michael R Kreutz
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Leibniz Group ‘Dendritic Organelles and Synaptic Function’, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
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Lavi A, Sehgal M, de Sousa AF, Ter-Mkrtchyan D, Sisan F, Luchetti A, Okabe A, Bear C, Silva AJ. Local memory allocation recruits memory ensembles across brain regions. Neuron 2023; 111:470-480.e5. [PMID: 36563678 PMCID: PMC10548338 DOI: 10.1016/j.neuron.2022.11.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 09/29/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
Memories are thought to be stored in ensembles of neurons across multiple brain regions. However, whether and how these ensembles are coordinated at the time of learning remains largely unknown. Here, we combined CREB-mediated memory allocation with transsynaptic retrograde tracing to demonstrate that the allocation of aversive memories to a group of neurons in one brain region directly affects the allocation of interconnected neurons in upstream brain regions in a behavioral- and brain region-specific manner in mice. Our analysis suggests that this cross-regional recruitment of presynaptic neurons is initiated by downstream memory neurons through a retrograde mechanism. Together with statistical modeling, our results indicate that in addition to the anterograde flow of information between brain regions, the establishment of interconnected, brain-wide memory traces relies on a retrograde mechanism that coordinates memory ensembles at the time of learning.
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Affiliation(s)
- Ayal Lavi
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Megha Sehgal
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Andre F de Sousa
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Donara Ter-Mkrtchyan
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Fardad Sisan
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Alessandro Luchetti
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Anna Okabe
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Cameron Bear
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Alcino J Silva
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA.
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38
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Murthy BKB, Somatakis S, Ulivi AF, Klimmt H, Castello-Waldow TP, Haynes N, Huettl RE, Chen A, Attardo A. Arc-driven mGRASP highlights CA1 to CA3 synaptic engrams. Front Behav Neurosci 2023; 16:1072571. [PMID: 36793796 PMCID: PMC9924068 DOI: 10.3389/fnbeh.2022.1072571] [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: 10/17/2022] [Accepted: 12/29/2022] [Indexed: 02/03/2023] Open
Abstract
Subpopulations of neurons display increased activity during memory encoding and manipulating the activity of these neurons can induce artificial formation or erasure of memories. Thus, these neurons are thought to be cellular engrams. Moreover, correlated activity between pre- and postsynaptic engram neurons is thought to lead to strengthening of their synaptic connections, thus increasing the probability of neural activity patterns occurring during encoding to reoccur at recall. Therefore, synapses between engram neurons can also be considered as a substrate of memory, or a synaptic engram. One can label synaptic engrams by targeting two complementary, non-fluorescent, synapse-targeted GFP fragments separately to the pre- and postsynaptic compartment of engram neurons; the two GFP fragments reconstitute a fluorescent GFP at the synaptic cleft between the engram neurons, thereby highlighting synaptic engrams. In this work we explored a transsynaptic GFP reconstitution system (mGRASP) to label synaptic engrams between hippocampal CA1 and CA3 engram neurons identified by different Immediate-Early Genes: cFos and Arc. We characterized the expression of the cellular and synaptic labels of the mGRASP system upon exposure to a novel environment or learning of a hippocampal-dependent memory task. We found that mGRASP under the control of transgenic ArcCreERT2 labeled synaptic engrams more efficiently than when controlled by viral cFostTA, possibly due to differences in the genetic systems rather than the specific IEG promoters.
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Affiliation(s)
- B. K. B. Murthy
- Leibniz Institute for Neurobiology, Magdeburg, Germany,Graduate School of Systemic Neurosciences, Munich, Germany,Max Planck Institute of Psychiatry, Munich, Germany
| | - S. Somatakis
- Max Planck Institute of Psychiatry, Munich, Germany
| | - A. F. Ulivi
- Leibniz Institute for Neurobiology, Magdeburg, Germany,Max Planck Institute of Psychiatry, Munich, Germany
| | - H. Klimmt
- Leibniz Institute for Neurobiology, Magdeburg, Germany,Max Planck Institute of Psychiatry, Munich, Germany,International Max Planck Research School for Translational Psychiatry, Munich, Germany
| | | | - N. Haynes
- Max Planck Institute of Psychiatry, Munich, Germany
| | - R. E. Huettl
- Max Planck Institute of Psychiatry, Munich, Germany
| | - A. Chen
- Graduate School of Systemic Neurosciences, Munich, Germany,Max Planck Institute of Psychiatry, Munich, Germany,International Max Planck Research School for Translational Psychiatry, Munich, Germany,Weizmann Institute of Science, Rehovot, Israel
| | - Alessio Attardo
- Leibniz Institute for Neurobiology, Magdeburg, Germany,Graduate School of Systemic Neurosciences, Munich, Germany,Max Planck Institute of Psychiatry, Munich, Germany,International Max Planck Research School for Translational Psychiatry, Munich, Germany,*Correspondence: Alessio Attardo,
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Fernández-Blanco Á, Zamora-Moratalla A, Sabariego-Navarro M, Dierssen M. Defective engram allocation contributes to impaired fear memory performance in Down syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.11.523460. [PMID: 36711850 PMCID: PMC9882045 DOI: 10.1101/2023.01.11.523460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Down syndrome (DS) is the most common genetic form of intellectual disability (ID). The cellular and molecular mechanisms contributing to ID in DS are not completely understood. Recent evidence indicates that a given memory is encoded by sparsely distributed neurons, highly activated during learning, the engram cells. Intriguingly, mechanisms that are of paramount importance for engram formation are impaired in DS. Here we explored engram formation in a DS mouse model, the Ts65Dn and we found a reduced number of engram cells in the dentate gyrus (DG), suggesting reduced neuronal allocation to engrams. We also show that trisomic engram cells present reduced number of mature spines than WT engram cells and their excitability is not enhanced during memory recall. In fact, activation of engram cells using a chemogenetic approach does not recover memory deficits in Ts65Dn. Altogether, our findings suggest that perturbations in engram neurons may play a significant role in memory alterations in DS.
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40
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Kim J, Kaang BK. Cyclic AMP response element-binding protein (CREB) transcription factor in astrocytic synaptic communication. Front Synaptic Neurosci 2023; 14:1059918. [PMID: 36685081 PMCID: PMC9845270 DOI: 10.3389/fnsyn.2022.1059918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 10/24/2022] [Indexed: 01/05/2023] Open
Abstract
Astrocytes are known to actively participate in synaptic communication by forming structures called tripartite synapses. These synapses consist of presynaptic axon terminals, postsynaptic dendritic spines, and astrocytic processes where astrocytes release and receive transmitters. Although the transcription factor cyclic AMP response element (CRE)-binding protein (CREB) has been actively studied as an important factor for mediating synaptic activity-induced responses in neurons, its role in astrocytes is relatively unknown. Synaptic signals are known to activate various downstream pathways in astrocytes, which can activate the CREB transcription factor. Therefore, there is a need to summarize studies on astrocytic intracellular pathways that are induced by synaptic communication resulting in activation of the CREB pathway. In this review, we discuss the various neurotransmitter receptors and intracellular pathways that can induce CREB activation and CREB-induced gene regulation in astrocytes.
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41
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Scott DN, Frank MJ. Adaptive control of synaptic plasticity integrates micro- and macroscopic network function. Neuropsychopharmacology 2023; 48:121-144. [PMID: 36038780 PMCID: PMC9700774 DOI: 10.1038/s41386-022-01374-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 11/09/2022]
Abstract
Synaptic plasticity configures interactions between neurons and is therefore likely to be a primary driver of behavioral learning and development. How this microscopic-macroscopic interaction occurs is poorly understood, as researchers frequently examine models within particular ranges of abstraction and scale. Computational neuroscience and machine learning models offer theoretically powerful analyses of plasticity in neural networks, but results are often siloed and only coarsely linked to biology. In this review, we examine connections between these areas, asking how network computations change as a function of diverse features of plasticity and vice versa. We review how plasticity can be controlled at synapses by calcium dynamics and neuromodulatory signals, the manifestation of these changes in networks, and their impacts in specialized circuits. We conclude that metaplasticity-defined broadly as the adaptive control of plasticity-forges connections across scales by governing what groups of synapses can and can't learn about, when, and to what ends. The metaplasticity we discuss acts by co-opting Hebbian mechanisms, shifting network properties, and routing activity within and across brain systems. Asking how these operations can go awry should also be useful for understanding pathology, which we address in the context of autism, schizophrenia and Parkinson's disease.
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Affiliation(s)
- Daniel N Scott
- Cognitive Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA.
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.
| | - Michael J Frank
- Cognitive Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA.
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.
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42
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Fan X, Song J, Ma C, Lv Y, Wang F, Ma L, Liu X. Noradrenergic signaling mediates cortical early tagging and storage of remote memory. Nat Commun 2022; 13:7623. [PMID: 36494350 PMCID: PMC9734098 DOI: 10.1038/s41467-022-35342-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
The neocortical prefrontal memory engram generated during initial learning is critical for remote episodic memory storage, however, the nature of early cortical tagging remains unknown. Here we found that in mice, increased norepinephrine (NE) release from the locus coeruleus (LC) to the medial prefrontal cortex (mPFC) during contextual fear conditioning (CFC) was critical for engram tagging and remote memory storage, which was regulated by the ventrolateral periaqueductal grey. β-Blocker infusion, or knockout of β1-adrenergic receptor (β1-AR) in the mPFC, impaired the storage of remote CFC memory, which could not be rescued by activation of LC-mPFC NE projection. Remote memory retrieval induced the activation of mPFC engram cells that were tagged during CFC. Inhibition of LC-mPFC NE projection or β1-AR knockout impaired mPFC engram tagging. Juvenile mice had fewer LC NE neurons than adults and showed deficiency in mPFC engram tagging and remote memory of CFC. Activation of β1-AR signaling promoted mPFC early tagging and remote memory storage in juvenile mice. Our data demonstrate that activation of LC NEergic signaling during CFC memory encoding mediates engram early tagging in the mPFC and systems consolidation of remote memory.
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Affiliation(s)
- Xiaocen Fan
- grid.8547.e0000 0001 0125 2443School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology, Pharmacology Research Center, Huashan Hospital, Fudan University, Shanghai, 200032 China ,grid.506261.60000 0001 0706 7839Research Unit of Addiction Memory, Chinese Academy of Medical Sciences (2021RU009), Shanghai, 200032 China
| | - Jiachen Song
- grid.8547.e0000 0001 0125 2443School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology, Pharmacology Research Center, Huashan Hospital, Fudan University, Shanghai, 200032 China ,grid.506261.60000 0001 0706 7839Research Unit of Addiction Memory, Chinese Academy of Medical Sciences (2021RU009), Shanghai, 200032 China
| | - Chaonan Ma
- grid.8547.e0000 0001 0125 2443School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology, Pharmacology Research Center, Huashan Hospital, Fudan University, Shanghai, 200032 China ,grid.506261.60000 0001 0706 7839Research Unit of Addiction Memory, Chinese Academy of Medical Sciences (2021RU009), Shanghai, 200032 China
| | - Yanbo Lv
- grid.8547.e0000 0001 0125 2443School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology, Pharmacology Research Center, Huashan Hospital, Fudan University, Shanghai, 200032 China ,grid.506261.60000 0001 0706 7839Research Unit of Addiction Memory, Chinese Academy of Medical Sciences (2021RU009), Shanghai, 200032 China
| | - Feifei Wang
- grid.8547.e0000 0001 0125 2443School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology, Pharmacology Research Center, Huashan Hospital, Fudan University, Shanghai, 200032 China ,grid.506261.60000 0001 0706 7839Research Unit of Addiction Memory, Chinese Academy of Medical Sciences (2021RU009), Shanghai, 200032 China
| | - Lan Ma
- grid.8547.e0000 0001 0125 2443School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology, Pharmacology Research Center, Huashan Hospital, Fudan University, Shanghai, 200032 China ,grid.506261.60000 0001 0706 7839Research Unit of Addiction Memory, Chinese Academy of Medical Sciences (2021RU009), Shanghai, 200032 China
| | - Xing Liu
- grid.8547.e0000 0001 0125 2443School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology, Pharmacology Research Center, Huashan Hospital, Fudan University, Shanghai, 200032 China ,grid.506261.60000 0001 0706 7839Research Unit of Addiction Memory, Chinese Academy of Medical Sciences (2021RU009), Shanghai, 200032 China
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Zhu Y, Zeng Y, Ren J, Zhang L, Chen C, Fernandez G, Qin S. Emotional learning retroactively promotes memory integration through rapid neural reactivation and reorganization. eLife 2022; 11:e60190. [PMID: 36476501 PMCID: PMC9815824 DOI: 10.7554/elife.60190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Neutral events preceding emotional experiences can be better remembered, likely by assigning them as significant to guide possible use in future. Yet, the neurobiological mechanisms of how emotional learning enhances memory for past mundane events remain unclear. By two behavioral studies and one functional magnetic resonance imaging study with an adapted sensory preconditioning paradigm, we show rapid neural reactivation and connectivity changes underlying emotion-charged retroactive memory enhancement. Behaviorally, emotional learning retroactively enhanced initial memory for neutral associations across the three studies. Neurally, emotional learning potentiated trial-specific reactivation of overlapping neural traces in the hippocampus and stimulus-relevant neocortex. It further induced rapid hippocampal-neocortical functional reorganization supporting such retroactive memory benefit, as characterized by enhanced hippocampal-neocortical coupling modulated by the amygdala during emotional learning, and a shift of hippocampal connectivity from stimulus-relevant neocortex to distributed transmodal prefrontal-parietal areas at post-learning rests. Together, emotional learning retroactively promotes memory integration for past neutral events through stimulating trial-specific reactivation of overlapping representations and reorganization of associated memories into an integrated network to foster its priority for future use.
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Affiliation(s)
- Yannan Zhu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal UniversityBeijingChina
- Beijing Key Laboratory of Brain Imaging and Connectomics, Beijing Normal UniversityBeijingChina
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical CenterNijmegenNetherlands
| | - Yimeng Zeng
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal UniversityBeijingChina
- Beijing Key Laboratory of Brain Imaging and Connectomics, Beijing Normal UniversityBeijingChina
| | - Jingyuan Ren
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical CenterNijmegenNetherlands
| | - Lingke Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal UniversityBeijingChina
- Beijing Key Laboratory of Brain Imaging and Connectomics, Beijing Normal UniversityBeijingChina
| | - Changming Chen
- School of Education, Chongqing Normal UniversityChongqingChina
| | - Guillen Fernandez
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical CenterNijmegenNetherlands
| | - Shaozheng Qin
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal UniversityBeijingChina
- Beijing Key Laboratory of Brain Imaging and Connectomics, Beijing Normal UniversityBeijingChina
- Chinese Institute for Brain ResearchBeijingChina
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44
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Park S, Jung JH, Karimi SA, Jacob AD, Josselyn SA. Opto-extinction of a threat memory in mice. Brain Res Bull 2022; 191:61-68. [DOI: 10.1016/j.brainresbull.2022.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/17/2022] [Indexed: 11/02/2022]
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45
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Wang J, Tambini A, Lapate RC. The tie that binds: temporal coding and adaptive emotion. Trends Cogn Sci 2022; 26:1103-1118. [PMID: 36302710 DOI: 10.1016/j.tics.2022.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 09/01/2022] [Accepted: 09/07/2022] [Indexed: 11/11/2022]
Abstract
Emotions are temporally dynamic, but the persistence of emotions outside of their appropriate temporal context is detrimental to health and well-being. Yet, precisely how temporal coding and emotional processing interact remains unclear. Recently unveiled temporal context representations in the hippocampus, entorhinal cortex (EC), and prefrontal cortex (PFC) support memory for what happened when. Here, we discuss how these neural temporal representations may interact with densely interconnected amygdala circuitry to shape emotional functioning. We propose a neuroanatomically informed framework suggesting that high-fidelity temporal representations linked to dynamic experiences promote emotion regulation and adaptive emotional memories. Then, we discuss how newly-identified synaptic and molecular features of amygdala-hippocampal projections suggest that intense, amygdala-dependent emotional responses may distort temporal-coding mechanisms. We conclude by identifying key avenues for future research.
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Affiliation(s)
- Jingyi Wang
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Arielle Tambini
- Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Regina C Lapate
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
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46
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Aitken K, Garrett M, Olsen S, Mihalas S. The geometry of representational drift in natural and artificial neural networks. PLoS Comput Biol 2022; 18:e1010716. [PMID: 36441762 PMCID: PMC9731438 DOI: 10.1371/journal.pcbi.1010716] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 12/08/2022] [Accepted: 11/07/2022] [Indexed: 11/29/2022] Open
Abstract
Neurons in sensory areas encode/represent stimuli. Surprisingly, recent studies have suggested that, even during persistent performance, these representations are not stable and change over the course of days and weeks. We examine stimulus representations from fluorescence recordings across hundreds of neurons in the visual cortex using in vivo two-photon calcium imaging and we corroborate previous studies finding that such representations change as experimental trials are repeated across days. This phenomenon has been termed "representational drift". In this study we geometrically characterize the properties of representational drift in the primary visual cortex of mice in two open datasets from the Allen Institute and propose a potential mechanism behind such drift. We observe representational drift both for passively presented stimuli, as well as for stimuli which are behaviorally relevant. Across experiments, the drift differs from in-session variance and most often occurs along directions that have the most in-class variance, leading to a significant turnover in the neurons used for a given representation. Interestingly, despite this significant change due to drift, linear classifiers trained to distinguish neuronal representations show little to no degradation in performance across days. The features we observe in the neural data are similar to properties of artificial neural networks where representations are updated by continual learning in the presence of dropout, i.e. a random masking of nodes/weights, but not other types of noise. Therefore, we conclude that a potential reason for the representational drift in biological networks is driven by an underlying dropout-like noise while continuously learning and that such a mechanism may be computational advantageous for the brain in the same way it is for artificial neural networks, e.g. preventing overfitting.
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Affiliation(s)
- Kyle Aitken
- MindScope Program, Allen Institute, Seattle, Washington, United States of America
- * E-mail:
| | - Marina Garrett
- MindScope Program, Allen Institute, Seattle, Washington, United States of America
| | - Shawn Olsen
- MindScope Program, Allen Institute, Seattle, Washington, United States of America
| | - Stefan Mihalas
- MindScope Program, Allen Institute, Seattle, Washington, United States of America
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Celorrio M, Rhodes J, Shumilov K, Moritz J, Xiao S, Anabayan I, Sauerbeck A, Kummer T, Friess S. Recombinant human erythropoietin induces neuroprotection, activates MAPK/CREB pathway, and rescues fear memory after traumatic brain injury with delayed hypoxemia in mice. Brain Res 2022; 1795:148074. [PMID: 36075467 PMCID: PMC10515732 DOI: 10.1016/j.brainres.2022.148074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 07/29/2022] [Accepted: 09/01/2022] [Indexed: 11/21/2022]
Abstract
Therapeutic interventions targeting secondary insults, such as delayed hypoxemia, provide a unique opportunity for treatment in severe traumatic brain injury (TBI). Erythropoietin (EPO) is a hypoxia-responsive cytokine with important roles in neurodevelopment, neuroprotection and neuromodulation. We hypothesized that recombinant human erythropoietin (rhEPO) administration would mitigate injury in a combined injury model of TBI and delayed hypoxemia. Utilizing a clinically relevant murine model of TBI and delayed hypoxemia, we characterized how ongoing rhEPO administration influenced neurogenesis, neuroprotection, synaptic density and, behavioral outcomes early after TBI, and the impact on long-lasting outcomes 6 months after injury. We employed novel object recognition (NOR) and fear conditioning to assess long-term memory. At 1-month post-injury, we observed a significant increase in cued-fear memory response in the rhEPO-injured mice compared with vehicle-injured mice. This was associated with neuroprotection and neurogenesis in the hippocampus and mitogen-activated protein kinase (MAPK)/cAMP response element-binding protein (CREB) signaling activation and increased of excitatory synaptic density in the amygdala. Early rhEPO treatment after injury reduced neurodegeneration and increased excitatory synaptic density in the hippocampus and amygdala at 6 months post-injury. However at 6 months post-injury (4 months after discontinuation of rhEPO), we did not observe changes in behavioral assessments nor MAPK/CREB pathway activation. In summary, these data demonstrate that ongoing rhEPO treatment initiated at a clinically feasible time point improves neurological, cognitive, and histological outcomes after TBI in the setting of secondary hypoxemic insults.
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Affiliation(s)
- Marta Celorrio
- Division of Critical Care Medicine, Department of Pediatrics, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - James Rhodes
- Division of Critical Care Medicine, Department of Pediatrics, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Kirill Shumilov
- Division of Critical Care Medicine, Department of Pediatrics, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Jennie Moritz
- Division of Critical Care Medicine, Department of Pediatrics, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Sophia Xiao
- Division of Critical Care Medicine, Department of Pediatrics, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Ilakkia Anabayan
- Division of Critical Care Medicine, Department of Pediatrics, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Andrew Sauerbeck
- Department of Neurology, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Terrance Kummer
- Department of Neurology, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Stuart Friess
- Division of Critical Care Medicine, Department of Pediatrics, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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48
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Lin YL, Yang ZS, Wong WY, Lin SC, Wang SJ, Chen SP, Cheng JK, Lu H, Lien CC. Cellular mechanisms underlying central sensitization in a mouse model of chronic muscle pain. eLife 2022; 11:78610. [PMID: 36377439 PMCID: PMC9665847 DOI: 10.7554/elife.78610] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 10/22/2022] [Indexed: 11/16/2022] Open
Abstract
Chronic pain disorders are often associated with negative emotions, including anxiety and depression. The central nucleus of the amygdala (CeA) has emerged as an integrative hub for nociceptive and affective components during central pain development. Prior adverse injuries are precipitating factors thought to transform nociceptors into a primed state for chronic pain. However, the cellular basis underlying the primed state and the subsequent development of chronic pain remains unknown. Here, we investigated the cellular and synaptic alterations of the CeA in a mouse model of chronic muscle pain. In these mice, local infusion of pregabalin, a clinically approved drug for fibromyalgia and other chronic pain disorders, into the CeA or chemogenetic inactivation of the somatostatin-expressing CeA (CeA-SST) neurons during the priming phase prevented the chronification of pain. Further, electrophysiological recording revealed that the CeA-SST neurons had increased excitatory synaptic drive and enhanced neuronal excitability in the chronic pain states. Finally, either chemogenetic inactivation of the CeA-SST neurons or pharmacological suppression of the nociceptive afferents from the brainstem to the CeA-SST neurons alleviated chronic pain and anxio-depressive symptoms. These data raise the possibility of targeting treatments to CeA-SST neurons to prevent central pain sensitization.
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Affiliation(s)
- Yu-Ling Lin
- Institute of Neuroscience, National Yang Ming Chiao Tung University
| | - Zhu-Sen Yang
- Institute of Neuroscience, National Yang Ming Chiao Tung University
| | - Wai-Yi Wong
- Institute of Neuroscience, National Yang Ming Chiao Tung University
| | - Shih-Che Lin
- Institute of Neuroscience, National Yang Ming Chiao Tung University
| | - Shuu-Jiun Wang
- Institute of Neuroscience, National Yang Ming Chiao Tung University
- Brain Research Center, National Yang Ming Chiao Tung University
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital
- Faculty of Medicine, National Yang Ming Chiao Tung University
| | - Shih-Pin Chen
- Institute of Neuroscience, National Yang Ming Chiao Tung University
- Brain Research Center, National Yang Ming Chiao Tung University
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital
- Faculty of Medicine, National Yang Ming Chiao Tung University
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University
| | - Jen-Kun Cheng
- Department of Medicine, MacKay Medical College
- Department of Anesthesiology, MacKay Memorial Hospital
| | - Hui Lu
- Department of Pharmacology and Physiology, George Washington University
| | - Cheng-Chang Lien
- Institute of Neuroscience, National Yang Ming Chiao Tung University
- Brain Research Center, National Yang Ming Chiao Tung University
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49
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Bechay KR, Abduljawad N, Latifi S, Suzuki K, Iwashita H, Carmichael ST. PDE2A Inhibition Enhances Axonal Sprouting, Functional Connectivity, and Recovery after Stroke. J Neurosci 2022; 42:8225-8236. [PMID: 36163142 PMCID: PMC9653274 DOI: 10.1523/jneurosci.0730-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 09/06/2022] [Accepted: 09/11/2022] [Indexed: 11/21/2022] Open
Abstract
Phosphodiesterase (PDE) inhibitors have been safely and effectively used in the clinic and increase the concentration of intracellular cyclic nucleotides (cAMP/cGMP). These molecules activate downstream mediators, including the cAMP response element-binding protein (CREB), which controls neuronal excitability and growth responses. CREB gain of function enhances learning and allocates neurons into memory engrams. CREB also controls recovery after stroke. PDE inhibitors are linked to recovery from neural damage and to stroke recovery in specific sites within the brain. PDE2A is enriched in cortex. In the present study, we use a mouse cortical stroke model in young adult and aged male mice to test the effect of PDE2A inhibition on functional recovery, and on downstream mechanisms of axonal sprouting, tissue repair, and the functional connectivity of neurons in recovering cortex. Stroke causes deficits in use of the contralateral forelimb, loss of axonal projections in cortex adjacent to the infarct, and functional disconnection of neuronal networks. PDE2A inhibition enhances functional recovery, increases axonal projections in peri-infarct cortex, and, through two-photon in vivo imaging, enhances the functional connectivity of motor system excitatory neurons. PDE2A inhibition after stroke does not have an effect on other aspects of tissue repair, such as angiogenesis, gliogenesis, neurogenesis, and inflammatory responses. These data suggest that PDE2A inhibition is an effective therapeutic approach for stroke recovery in the rodent and that it simultaneously enhances connectivity in peri-infarct neuronal populations.SIGNIFICANCE STATEMENT Inhibition of PDE2A enhances motor recovery, axonal projections, and functional connectivity of neurons in peri-infarct tissue. This represents an avenue for a pharmacological therapy for stroke recovery.
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Affiliation(s)
- Kirollos Raouf Bechay
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Nora Abduljawad
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Shahrzad Latifi
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Kazunori Suzuki
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa 251-8555, Japan
| | - Hiroki Iwashita
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa 251-8555, Japan
| | - S Thomas Carmichael
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
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50
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Chowdhury A, Luchetti A, Fernandes G, Filho DA, Kastellakis G, Tzilivaki A, Ramirez EM, Tran MY, Poirazi P, Silva AJ. A locus coeruleus-dorsal CA1 dopaminergic circuit modulates memory linking. Neuron 2022; 110:3374-3388.e8. [PMID: 36041433 PMCID: PMC10508214 DOI: 10.1016/j.neuron.2022.08.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/07/2022] [Accepted: 07/31/2022] [Indexed: 11/20/2022]
Abstract
Individual memories are often linked so that the recall of one triggers the recall of another. For example, contextual memories acquired close in time can be linked, and this is known to depend on a temporary increase in excitability that drives the overlap between dorsal CA1 (dCA1) hippocampal ensembles that encode the linked memories. Here, we show that locus coeruleus (LC) cells projecting to dCA1 have a key permissive role in contextual memory linking, without affecting contextual memory formation, and that this effect is mediated by dopamine. Additionally, we found that LC-to-dCA1-projecting neurons modulate the excitability of dCA1 neurons and the extent of overlap between dCA1 memory ensembles as well as the stability of coactivity patterns within these ensembles. This discovery of a neuromodulatory system that specifically affects memory linking without affecting memory formation reveals a fundamental separation between the brain mechanisms modulating these two distinct processes.
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Affiliation(s)
- Ananya Chowdhury
- Departments of Neurobiology, Psychiatry & Biobehavioral Sciences, and Psychology, Integrative Center for Learning and Memory, and Brain Research Institute, UCLA, Los Angeles, CA 90095
| | - Alessandro Luchetti
- Departments of Neurobiology, Psychiatry & Biobehavioral Sciences, and Psychology, Integrative Center for Learning and Memory, and Brain Research Institute, UCLA, Los Angeles, CA 90095
| | - Giselle Fernandes
- Departments of Neurobiology, Psychiatry & Biobehavioral Sciences, and Psychology, Integrative Center for Learning and Memory, and Brain Research Institute, UCLA, Los Angeles, CA 90095
| | - Daniel Almeida Filho
- Departments of Neurobiology, Psychiatry & Biobehavioral Sciences, and Psychology, Integrative Center for Learning and Memory, and Brain Research Institute, UCLA, Los Angeles, CA 90095
| | - George Kastellakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Hellas (FORTH), Vassilica Vouton, PO Box 1527, GR 711 10 Heraklion, Crete, Greece
| | - Alexandra Tzilivaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Hellas (FORTH), Vassilica Vouton, PO Box 1527, GR 711 10 Heraklion, Crete, Greece
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health Charitéplatz 1, 10117 Berlin Germany
- Einstein Center for Neurosciences Berlin Charitéplatz 1, 10117 Berlin Germany
- Neurocure Cluster of Excellence Charitéplatz 1, 10117 Berlin, Germany
| | - Erica M Ramirez
- Departments of Neurobiology, Psychiatry & Biobehavioral Sciences, and Psychology, Integrative Center for Learning and Memory, and Brain Research Institute, UCLA, Los Angeles, CA 90095
| | - Mary Y Tran
- Departments of Neurobiology, Psychiatry & Biobehavioral Sciences, and Psychology, Integrative Center for Learning and Memory, and Brain Research Institute, UCLA, Los Angeles, CA 90095
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Hellas (FORTH), Vassilica Vouton, PO Box 1527, GR 711 10 Heraklion, Crete, Greece
| | - Alcino J Silva
- Departments of Neurobiology, Psychiatry & Biobehavioral Sciences, and Psychology, Integrative Center for Learning and Memory, and Brain Research Institute, UCLA, Los Angeles, CA 90095
- Lead contact
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