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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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Madanlal D, Guinard C, Nuñez VP, Becker S, Garnham J, Khayachi A, Léger S, O'Donovan C, Singh S, Stern S, Slaney C, Trappenberg T, Alda M, Nunes A. A pilot study examining the impact of lithium treatment and responsiveness on mnemonic discrimination in bipolar disorder. J Affect Disord 2024; 351:49-57. [PMID: 38280568 DOI: 10.1016/j.jad.2024.01.146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/09/2024] [Accepted: 01/14/2024] [Indexed: 01/29/2024]
Abstract
INTRODUCTION Mnemonic discrimination (MD), the ability to discriminate new stimuli from similar memories, putatively involves dentate gyrus pattern separation. Since lithium may normalize dentate gyrus functioning in lithium-responsive bipolar disorder (BD), we hypothesized that lithium treatment would be associated with better MD in lithium-responsive BD patients. METHODS BD patients (N = 69; NResponders = 16 [23 %]) performed the Continuous Visual Memory Test (CVMT), which requires discriminating between novel and previously seen images. Before testing, all patients had prophylactic lithium responsiveness assessed over ≥1 year of therapy (with the Alda Score), although only thirty-eight patients were actively prescribed lithium at time of testing (55 %; 12/16 responders, 26/53 nonresponders). We then used computational modelling to extract patient-specific MD indices. Linear models were used to test how (A) lithium treatment, (B) lithium responsiveness via the continuous Alda score, and (C) their interaction, affected MD. RESULTS Superior MD performance was associated with lithium treatment exclusively in lithium-responsive patients (Lithium x AldaScore β = 0.257 [SE 0.078], p = 0.002). Consistent with prior literature, increased age was associated with worse MD (β = -0.03 [SE 0.01], p = 0.005). LIMITATIONS Secondary pilot analysis of retrospectively collected data in a cross-sectional design limits generalizability. CONCLUSION Our study is the first to examine MD performance in BD. Lithium is associated with better MD performance only in lithium responders, potentially due to lithium's effects on dentate gyrus granule cell excitability. Our results may influence the development of behavioural probes for dentate gyrus neuronal hyperexcitability in BD.
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Affiliation(s)
- Dhanyaasri Madanlal
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Christian Guinard
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada; Faculty of Computer Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Vanessa Pardo Nuñez
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Suzanna Becker
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Julie Garnham
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Anouar Khayachi
- Montreal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Simon Léger
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Claire O'Donovan
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Selena Singh
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Shani Stern
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Israel
| | - Claire Slaney
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Thomas Trappenberg
- Faculty of Computer Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Martin Alda
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Abraham Nunes
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada; Faculty of Computer Science, Dalhousie University, Halifax, Nova Scotia, Canada.
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Bird AD, Cuntz H, Jedlicka P. Robust and consistent measures of pattern separation based on information theory and demonstrated in the dentate gyrus. PLoS Comput Biol 2024; 20:e1010706. [PMID: 38377108 PMCID: PMC10906873 DOI: 10.1371/journal.pcbi.1010706] [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: 11/03/2022] [Revised: 03/01/2024] [Accepted: 12/13/2023] [Indexed: 02/22/2024] Open
Abstract
Pattern separation is a valuable computational function performed by neuronal circuits, such as the dentate gyrus, where dissimilarity between inputs is increased, reducing noise and increasing the storage capacity of downstream networks. Pattern separation is studied from both in vivo experimental and computational perspectives and, a number of different measures (such as orthogonalisation, decorrelation, or spike train distance) have been applied to quantify the process of pattern separation. However, these are known to give conclusions that can differ qualitatively depending on the choice of measure and the parameters used to calculate it. We here demonstrate that arbitrarily increasing sparsity, a noticeable feature of dentate granule cell firing and one that is believed to be key to pattern separation, typically leads to improved classical measures for pattern separation even, inappropriately, up to the point where almost all information about the inputs is lost. Standard measures therefore both cannot differentiate between pattern separation and pattern destruction, and give results that may depend on arbitrary parameter choices. We propose that techniques from information theory, in particular mutual information, transfer entropy, and redundancy, should be applied to penalise the potential for lost information (often due to increased sparsity) that is neglected by existing measures. We compare five commonly-used measures of pattern separation with three novel techniques based on information theory, showing that the latter can be applied in a principled way and provide a robust and reliable measure for comparing the pattern separation performance of different neurons and networks. We demonstrate our new measures on detailed compartmental models of individual dentate granule cells and a dentate microcircuit, and show how structural changes associated with epilepsy affect pattern separation performance. We also demonstrate how our measures of pattern separation can predict pattern completion accuracy. Overall, our measures solve a widely acknowledged problem in assessing the pattern separation of neural circuits such as the dentate gyrus, as well as the cerebellum and mushroom body. Finally we provide a publicly available toolbox allowing for easy analysis of pattern separation in spike train ensembles.
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Affiliation(s)
- Alexander D. Bird
- Computer-Based Modelling in the field of 3R Animal Protection, ICAR3R, Faculty of Medicine, Justus Liebig University, Giessen, Germany
- Ernst Strüngmann Institute (ESI) for Neuroscience in cooperation with the Max Planck Society, Frankfurt-am-Main, Germany
- Frankfurt Institute for Advanced Studies, Frankfurt-am-Main, Germany
- Translational Neuroscience Network Giessen, Germany
| | - Hermann Cuntz
- Ernst Strüngmann Institute (ESI) for Neuroscience in cooperation with the Max Planck Society, Frankfurt-am-Main, Germany
- Frankfurt Institute for Advanced Studies, Frankfurt-am-Main, Germany
- Translational Neuroscience Network Giessen, Germany
| | - Peter Jedlicka
- Computer-Based Modelling in the field of 3R Animal Protection, ICAR3R, Faculty of Medicine, Justus Liebig University, Giessen, Germany
- Translational Neuroscience Network Giessen, Germany
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Sarma R, Willis N, Holthaus TA, Cannavale CN, Gibbs HD, Khan N. Memory Abilities Are Selectively Related to Food Label and Numeracy Nutrition Skills. JOURNAL OF NUTRITION EDUCATION AND BEHAVIOR 2023; 55:861-868. [PMID: 37921796 DOI: 10.1016/j.jneb.2023.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 11/04/2023]
Abstract
OBJECTIVE We investigated the relationship between nutrition literacy, diet quality, carotenoid status, and cognition. METHODS Adults aged 37.5 ± 17.0 years (n = 52) completed the 42-item Nutrition Literacy Assessment Instrument (NLit). The Dietary History Questionnaire III was analyzed to determine the Healthy Eating Index. Skin carotenoids were assessed as a diet quality biomarker. Selective attention, relational memory, and pattern separation abilities were assessed using the flanker, spatial reconstruction, and mnemonic similarity tasks, respectively. Statistical adjustments included age, sex, education, and body mass index. RESULTS No correlations were observed for NLit scores and NLit subscales with Healthy Eating Index and skin carotenoid status. However, the NLit's food label and numeracy subscale was related to greater pattern separation abilities (ρ = 0.33, r2 = 0.11, P = 0.03). CONCLUSIONS AND IMPLICATIONS Comprehension of food labels and numeracy information was associated with memory abilities. Future work is needed to test whether targeting working memory and attentional processes during memory retrieval in larger samples may facilitate the acquisition of nutrition knowledge.
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Affiliation(s)
- Rhea Sarma
- Kinesiology and Community Health, University of Illinois, Urbana, IL
| | - Nathaniel Willis
- Division of Nutritional Sciences, University of Illinois, Urbana, IL
| | - Tori A Holthaus
- Division of Nutritional Sciences, University of Illinois, Urbana, IL
| | | | - Heather D Gibbs
- Department of Dietetics and Nutrition, University of Kansas Medical Center, Kansas City, KS
| | - Naiman Khan
- Kinesiology and Community Health, University of Illinois, Urbana, IL; Division of Nutritional Sciences, University of Illinois, Urbana, IL; Neuroscience Program, University of Illinois, Urbana, IL.
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5
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Sahakyan L, Wahlheim CN, Kwapil TR. Mnemonic discrimination deficits in multidimensional schizotypy. Hippocampus 2023; 33:1139-1153. [PMID: 37345675 DOI: 10.1002/hipo.23566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 04/29/2023] [Accepted: 06/02/2023] [Indexed: 06/23/2023]
Abstract
Current developmental psychopathology models indicate that schizophrenia can be understood as the most extreme expression of a multidimensional continuum of symptoms and impairment referred to as schizotypy. In nondisordered adults, schizotypy predicts risk for developing schizophrenia-spectrum psychopathology. Schizophrenia is associated with disruptions in detecting subtle differences between objects, which is linked to hippocampal dysfunction. These disruptions have been shown in the Mnemonic Similarity Task (MST) when patients are less likely to reject lures that are similar but not identical to studied objects, and instead mistake them for studied items. This pattern of errors may be a behavioral manifestation of impaired pattern separation, a key episodic memory ability associated with hippocampal integrity and overreliance on pattern completion. We examined whether multidimensional schizotypy is associated with such deficits in nondisordered young adults. Participants (n = 230) were assessed for positive, negative, and disorganized schizotypy and completed the MST and a perceptual discrimination task. MST performance showed that a combination of elevated negative and disorganized schizotypy was associated with decreased rejections of similar lures because they were mistakenly identified as studied items. These deficits were not observed in traditional recognition measures within the same task, nor in perceptual discrimination, suggesting that mnemonic discrimination deficits assessed by MST were selective and did not reflect generalized deficits. These findings extend the results obtained in schizophrenia patients and support a multidimensional model of schizophrenia-spectrum psychopathology.
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Affiliation(s)
- Lili Sahakyan
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
| | - Christopher N Wahlheim
- Department of Psychology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Thomas R Kwapil
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
- Department of Psychology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
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Munari L, Patel V, Johnson N, Mariottini C, Prabha S, Blitzer RD, Iyengar R. Memory discrimination is promoted by the expression of the transcription repressor WT1 in the dentate gyrus. Front Behav Neurosci 2023; 17:1130840. [PMID: 37830039 PMCID: PMC10564998 DOI: 10.3389/fnbeh.2023.1130840] [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: 12/23/2022] [Accepted: 08/14/2023] [Indexed: 10/14/2023] Open
Abstract
The hippocampus is critical for the precise formation of contextual memories. Overlapping inputs coming from the entorhinal cortex are processed by the trisynaptic pathway to form distinct memories. Disruption in any step of the circuit flow can lead to a lack of memory precision, and to memory interference. We have identified the transcriptional repressor Wilm's Tumor 1 (WT1) as an important regulator of synaptic plasticity involved in memory discrimination in the hippocampus. In male mice, using viral and transgenic approaches, we showed that WT1 deletion in granule cells of the dentate gyrus (DG) disrupts memory discrimination. With electrophysiological methods, we then identified changes in granule cells' excitability and DG synaptic transmission indicating that WT1 knockdown in DG granule cells disrupts the inhibitory feedforward input from mossy fibers to CA3 by decreasing mIPSCs and shifting the normal excitatory/inhibitory (E/I) balance in the DG → CA3 circuit in favor of excitation. Finally, using a chemogenetic approach, we established a causal link between granule cell hyperexcitability and memory discrimination impairments. Our results suggest that WT1 enables a circuit-level computation that drives pattern discrimination behavior.
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Affiliation(s)
| | | | | | | | | | | | - Ravi Iyengar
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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İmamoğlu A, Wahlheim CN, Belger A, S Giovanello K. Impaired mnemonic discrimination in children and adolescents at risk for schizophrenia. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2023; 9:39. [PMID: 37344455 DOI: 10.1038/s41537-023-00366-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 05/23/2023] [Indexed: 06/23/2023]
Abstract
People with schizophrenia and their high-risk, first-degree relatives report widespread episodic memory impairments that are purportedly due, at least in part, to failures of mnemonic discrimination. Here, we examined the status of mnemonic discrimination in 36 children and adolescents (aged 11-17 years) with and without familial risk for schizophrenia by employing an object-based recognition task called the Mnemonic Similarity Task (MST). The MST assesses the ability to discriminate between studied images and unstudied images that are either perceptually similar to studied images or completely novel. We compared 16 high-risk, unaffected first-degree relatives of people with schizophrenia, bipolar disorder, and/or schizoaffective disorder to 20 low-risk, control participants. High-risk participants showed worse mnemonic discrimination than low-risk participants, with no difference in recognition memory or perceptual discrimination. Our findings demonstrate that mnemonic discrimination deficits previously observed in people with schizophrenia are also present in their young, high-risk, first-degree relatives.
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Affiliation(s)
- Aslıhan İmamoğlu
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, US.
| | | | - Aysenil Belger
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, US
| | - Kelly S Giovanello
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, US
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, US
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Zichó K, Sos KE, Papp P, Barth AM, Misák E, Orosz Á, Mayer MI, Sebestény RZ, Nyiri G. Fear memory recall involves hippocampal somatostatin interneurons. PLoS Biol 2023; 21:e3002154. [PMID: 37289847 DOI: 10.1371/journal.pbio.3002154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 05/09/2023] [Indexed: 06/10/2023] Open
Abstract
Fear-related memory traces are encoded by sparse populations of hippocampal principal neurons that are recruited based on their inhibitory-excitatory balance during memory formation. Later, the reactivation of the same principal neurons can recall the memory. The details of this mechanism are still unclear. Here, we investigated whether disinhibition could play a major role in this process. Using optogenetic behavioral experiments, we found that when fear was associated with the inhibition of mouse hippocampal somatostatin positive interneurons, the re-inhibition of the same interneurons could recall fear memory. Pontine nucleus incertus neurons selectively inhibit hippocampal somatostatin cells. We also found that when fear was associated with the activity of these incertus neurons or fibers, the reactivation of the same incertus neurons or fibers could also recall fear memory. These incertus neurons showed correlated activity with hippocampal principal neurons during memory recall and were strongly innervated by memory-related neocortical centers, from which the inputs could also control hippocampal disinhibition in vivo. Nonselective inhibition of these mouse hippocampal somatostatin or incertus neurons impaired memory recall. Our data suggest a novel disinhibition-based memory mechanism in the hippocampus that is supported by local somatostatin interneurons and their pontine brainstem inputs.
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Affiliation(s)
- Krisztián Zichó
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Katalin E Sos
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Péter Papp
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Albert M Barth
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Erik Misák
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Áron Orosz
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Márton I Mayer
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Réka Z Sebestény
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Gábor Nyiri
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
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Koller WN, Cannon TD. Aberrant memory and delusional ideation: A pernicious partnership? Clin Psychol Rev 2023; 99:102231. [PMID: 36469975 DOI: 10.1016/j.cpr.2022.102231] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 06/02/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022]
Abstract
Delusions can be conceptualized as beliefs that are both at odds with consensus reality and espoused with high conviction. While delusions represent a cardinal symptom of schizophrenia, delusion-like beliefs can be found in the general population. Do similar cognitive mechanisms support delusionality across this spectrum? If so, what are they? Here, we examine evidence for a mechanistic role of the (associative) memory system in the formation and maintenance of delusions and delusion-like beliefs. While general neurocognitive metrics do not tend to associate with delusionality, our scoping review of the clinical and subclinical literature reveals several subdomains of memory function that do. These include a propensity to commit errors of commission (i.e., false alarms and intrusions), source memory biases, and metamemory impairment. We discuss how several of these effects may stem from aberrant associative memory function and offer recommendations for future research. Further, we propose a state/trait interaction model in which underlying traits (i.e., impaired associative and metamemory function) may become coupled with delusionality during states of acute psychosis, when memory function is particularly challenged by aberrant salience attribution and noisy perceptual input. According to this model, delusions may arise as explanations to high-salience (but low-source) mnemonic content that is endorsed with high confidence.
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Affiliation(s)
- William N Koller
- Department of Psychology, Yale University, Hillhouse Avenue, New Haven, CT 06520-8205, United States of America.
| | - Tyrone D Cannon
- Department of Psychology, Yale University, Hillhouse Avenue, New Haven, CT 06520-8205, United States of America
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10
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Parallel Pathways Provide Hippocampal Spatial Information to Prefrontal Cortex. J Neurosci 2023; 43:68-81. [PMID: 36414405 PMCID: PMC9838712 DOI: 10.1523/jneurosci.0846-22.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 10/06/2022] [Accepted: 11/07/2022] [Indexed: 11/23/2022] Open
Abstract
Long-range synaptic connections define how information flows through neuronal networks. Here, we combined retrograde and anterograde trans-synaptic viruses to delineate areas that exert direct and indirect influence over the dorsal and ventral prefrontal cortex (PFC) of the rat (both sexes). Notably, retrograde tracing using pseudorabies virus (PRV) revealed that both dorsal and ventral areas of the PFC receive prominent disynaptic input from the dorsal CA3 (dCA3) region of the hippocampus. The PRV experiments also identified candidate anatomical relays for this disynaptic pathway, namely, the ventral hippocampus, lateral septum, thalamus, amygdala, and basal forebrain. To determine the viability of each of these relays, we performed three additional experiments. In the first, we injected the retrograde monosynaptic tracer Fluoro-Gold into the PFC and the anterograde monosynaptic tracer Fluoro-Ruby into the dCA3 to confirm the first-order connecting areas and revealed several potential relay regions between the PFC and dCA3. In the second, we combined PRV injection in the PFC with polysynaptic anterograde viral tracer (HSV-1) in the dCA3 to reveal colabeled connecting neurons, which were evident only in the ventral hippocampus. In the third, we combined retrograde adeno-associated virus (AAV) injections in the PFC with an anterograde AAV in the dCA3 to reveal anatomical relay neurons in the ventral hippocampus and dorsal lateral septum. Together, these findings reveal parallel disynaptic pathways from the dCA3 to the PFC, illuminating a new anatomical framework for understanding hippocampal-prefrontal interactions. We suggest that the representation of context and space may be a universal feature of prefrontal function.SIGNIFICANCE STATEMENT The known functions of the prefrontal cortex are shaped by input from multiple brain areas. We used transneuronal viral tracing to discover multiple prominent disynaptic pathways through which the dorsal hippocampus (specifically, the dorsal CA3) has the potential to shape the actions of the prefrontal cortex. The demonstration of neuronal relays in the ventral hippocampus and lateral septum presents a new foundation for understanding long-range influences over prefrontal interactions, including the specific contribution of the dorsal CA3 to prefrontal function.
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11
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Rukundo P, Feng T, Pham V, Pieraut S. Moderate effect of early-life experience on dentate gyrus function. Mol Brain 2022; 15:92. [PMID: 36411441 PMCID: PMC9677655 DOI: 10.1186/s13041-022-00980-1] [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: 08/25/2022] [Accepted: 11/06/2022] [Indexed: 11/22/2022] Open
Abstract
The development, maturation, and plasticity of neural circuits are strongly influenced by experience and the interaction of an individual with their environment can have a long-lasting effect on cognitive function. Using an enriched environment (EE) paradigm, we have recently demonstrated that enhancing social, physical, and sensory activity during the pre-weaning time in mice led to an increase of inhibitory and excitatory synapses in the dentate gyrus (DG) of the hippocampus. The structural plasticity induced by experience may affect information processing in the circuit. The DG performs pattern separation, a computation that enables the encoding of very similar and overlapping inputs into dissimilar outputs. In the presented study, we have tested the hypothesis that an EE in juvenile mice will affect DG's functions that are relevant for pattern separation: the decorrelation of the inputs from the entorhinal cortex (EC) and the recruitment of the principal excitatory granule cell (GC) during behavior. First, using a novel slice electrophysiology protocol, we found that the transformation of the incoming signal from the EC afferents by individual GC is moderately affected by EE. We further show that EE does not affect behaviorally induced recruitment of principal excitatory GC. Lastly, using the novel object recognition task, a hippocampus-dependent memory test, we show that the ontogeny of this discrimination task was similar among the EE mice and the controls. Taken together, our work demonstrates that pre-weaning enrichment moderately affects DG function.
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Affiliation(s)
- Pacifique Rukundo
- grid.266818.30000 0004 1936 914XDepartment of Biology, University of Nevada, Reno, NV 89557 USA
| | - Ting Feng
- grid.266818.30000 0004 1936 914XDepartment of Biology, University of Nevada, Reno, NV 89557 USA
| | - Vincent Pham
- grid.266818.30000 0004 1936 914XDepartment of Biology, University of Nevada, Reno, NV 89557 USA
| | - Simon Pieraut
- grid.266818.30000 0004 1936 914XDepartment of Biology, University of Nevada, Reno, NV 89557 USA
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McNerlin C, Guan F, Bronk L, Lei K, Grosshans D, Young DW, Gaber MW, Maletic-Savatic M. Targeting hippocampal neurogenesis to protect astronauts' cognition and mood from decline due to space radiation effects. LIFE SCIENCES IN SPACE RESEARCH 2022; 35:170-179. [PMID: 36336363 DOI: 10.1016/j.lssr.2022.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/30/2022] [Accepted: 07/26/2022] [Indexed: 06/16/2023]
Abstract
Neurogenesis is an essential, lifelong process during which neural stem cells generate new neurons within the hippocampus, a center for learning, memory, and mood control. Neural stem cells are vulnerable to environmental insults spanning from chronic stress to radiation. These insults reduce their numbers and diminish neurogenesis, leading to memory decline, anxiety, and depression. Preserving neural stem cells could thus help prevent these neurogenesis-associated pathologies, an outcome particularly important for long-term space missions where environmental exposure to radiation is significantly higher than on Earth. Multiple developments, from mechanistic discoveries of radiation injury on hippocampal neurogenesis to new platforms for the development of selective, specific, effective, and safe small molecules as neurogenesis-protective agents hold great promise to minimize radiation damage on neurogenesis. In this review, we summarize the effects of space-like radiation on hippocampal neurogenesis. We then focus on current advances in drug discovery and development and discuss the nuclear receptor TLX/NR2E1 (oleic acid receptor) as an example of a neurogenic target that might rescue neurogenesis following radiation.
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Affiliation(s)
- Clare McNerlin
- Georgetown University School of Medicine, 3900 Reservoir Rd NW, Washington D.C. 20007, United States of America
| | - Fada Guan
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, 06510, United States of America
| | - Lawrence Bronk
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, United States of America
| | - Kevin Lei
- Graduate School for Biomedical Sciences, Baylor College of Medicine, Houston, Texas, 77030, United States of America; Jan and Dan Duncan Neurological Research Institute, 1250 Moursund St. Houston, TX 77030, United States of America
| | - David Grosshans
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, United States of America
| | - Damian W Young
- Jan and Dan Duncan Neurological Research Institute, 1250 Moursund St. Houston, TX 77030, United States of America; Center for Drug Discovery, Department of Pathology and Immunology Baylor College of Medicine, Houston, Texas, 77030, United States of America; Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, United States of America
| | - M Waleed Gaber
- Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States of America.
| | - Mirjana Maletic-Savatic
- Jan and Dan Duncan Neurological Research Institute, 1250 Moursund St. Houston, TX 77030, United States of America; Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States of America; Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States of America.
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13
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Wang H, Sun N, Wang X, Han J, Zhang Y, Huang Y, Zhou W. A touchscreen-based paradigm to measure visual pattern separation and pattern completion in mice. Front Neurosci 2022; 16:947742. [PMID: 36090275 PMCID: PMC9449699 DOI: 10.3389/fnins.2022.947742] [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: 05/19/2022] [Accepted: 07/29/2022] [Indexed: 11/27/2022] Open
Abstract
Memory accuracy involves two major processes: pattern separation and pattern completion. Pattern separation refers to the ability to reduce overlap among similar inputs to avoid interference, and pattern completion refers to the ability to retrieve the whole information from partial or degraded cues. Impairments in pattern separation/pattern completion contribute to cognitive deficits in several diseases of the nervous system. Therefore, it is better to evaluate both pattern separation and pattern completion in one apparatus. However, few tools are available to assess pattern separation and pattern completion within the same apparatus for rodents. In this study, we designed a series of images with varying degrees of similarity to the correct image to evaluate pattern separation and pattern completion. First, mice were trained to discriminate between two totally different images, and once the correct percentage reached above 77% for two consecutive days, the images with different degrees of similarity were used to measure pattern separation and pattern completion. The results showed the mice performed progressively worse from S0 to S4 (increasing similarity) when discriminating similar images in pattern separation, and the mice performed progressively worse from C0 to C4 (decreasing cues information) when recalling the correct image according to partial cues in pattern completion, implying a good image similarity-dependent manner for memory accuracy evaluation. In sum, we designed a convenient, effective paradigm to evaluate pattern separation and pattern completion based on a touchscreen pairwise discrimination task, which may provide a new method for the studies of the effects and mechanisms of memory accuracy enhancing drugs.
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Affiliation(s)
- Hao Wang
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Na Sun
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Xinyue Wang
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Jinyuan Han
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Yongxiang Zhang
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Yan Huang
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- *Correspondence: Yan Huang,
| | - Wenxia Zhou
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- Wenxia Zhou,
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14
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Positive schizotypy is associated with amplified mnemonic discrimination and attenuated generalization. Eur Arch Psychiatry Clin Neurosci 2022; 273:447-458. [PMID: 35624200 PMCID: PMC10070292 DOI: 10.1007/s00406-022-01430-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 05/09/2022] [Indexed: 11/03/2022]
Abstract
Tendency to experience inaccurate beliefs alongside perceptual anomalies constitutes positive schizotypal traits in the general population and shows continuity with the positive symptoms of schizophrenia. It has been hypothesized that the positive symptomatology of schizophrenia, and by extension, the odd beliefs and unusual perceptual experiences in the general population, are associated with specific alterations in memory functions. An imbalance between memory generalization and episodic memory specificity has been proposed on several counts; however, the direction of the imbalance is currently unclear. Here, we evaluated the association between positive schizotypy, and memory alterations related to hippocampal computations in a general population sample enriched for positive schizotypy. We found that memory generalization is attenuated while memory specificity is elevated in participants with more pronounced positive schizotypal traits. Our findings show that people who are prone to irrational beliefs and unusual experiences also show measurable alterations in memory and likely have difficulty grasping the global picture and rather be overpowered by fragments of information.
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15
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The shallow cognitive map hypothesis: A hippocampal framework for thought disorder in schizophrenia. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2022; 8:34. [PMID: 35853896 PMCID: PMC9261089 DOI: 10.1038/s41537-022-00247-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 03/11/2022] [Indexed: 12/31/2022]
Abstract
Memories are not formed in isolation. They are associated and organized into relational knowledge structures that allow coherent thought. Failure to express such coherent thought is a key hallmark of Schizophrenia. Here we explore the hypothesis that thought disorder arises from disorganized Hippocampal cognitive maps. In doing so, we combine insights from two key lines of investigation, one concerning the neural signatures of cognitive mapping, and another that seeks to understand lower-level cellular mechanisms of cognition within a dynamical systems framework. Specifically, we propose that multiple distinct pathological pathways converge on the shallowing of Hippocampal attractors, giving rise to disorganized Hippocampal cognitive maps and driving conceptual disorganization. We discuss the available evidence at the computational, behavioural, network, and cellular levels. We also outline testable predictions from this framework, including how it could unify major chemical and psychological theories of schizophrenia and how it can provide a rationale for understanding the aetiology and treatment of the disease.
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16
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van Hagen BTJ, van Goethem NP, Nelissen E, Paes D, Koymans K, van Hoof S, Schreiber R, Varney M, Newman-Tancredi A, Prickaerts J. Biased 5-HT 1A receptor agonists F13714 and NLX-101 differentially affect pattern separation and neuronal plasticity in rats after acute and chronic treatment. Mol Cell Neurosci 2022; 120:103719. [PMID: 35283305 DOI: 10.1016/j.mcn.2022.103719] [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: 10/07/2021] [Revised: 02/16/2022] [Accepted: 03/07/2022] [Indexed: 11/28/2022] Open
Abstract
Pattern separation is a hippocampal process in which highly similar stimuli are recognized as separate representations, and deficits could lead to memory impairments in neuropsychiatric disorders such as schizophrenia. The 5-HT1A receptor (5-HT1AR) is believed to be involved in these hippocampal pattern separation processes. However, in the dorsal raphe nucleus (DRN), the 5-HT1AR is expressed as a somatodendritic autoreceptor, negatively regulates serotonergic signaling, and could thereby counteract the effects of hippocampal postsynaptic 5-HT1A receptors. Therefore, this study aims to identify how pre- and post-synaptic 5-HT1AR activity affects pattern separation. Object pattern separation (OPS) performance was measured in male Wistar rats after both acute and chronic treatment (i.p.) with 5-HT1AR biased agonists F13714 (0.0025 mg/kg acutely, 0.02 mg/kg/day chronically) or NLX-101 (0.08 mg/kg acutely, 0.32 mg/kg/day chronically), which preferentially activate autoreceptors or postsynaptic receptors respectively, for 14 days. Body temperature - a functional correlate of hypothalamic 5-HT1AR stimulation - was measured daily. Additionally, 5-HT1AR density (DRN) and plasticity markers (hippocampus) were assessed. Acute treatment with F13714 impaired OPS performance, whereas chronic treatment normalized this, and a drop in body temperature was found from day 4 onwards. NLX-101 enhanced OPS performance acutely and chronically, and caused an acute drop in body temperature. Chronic NLX-101 treatment increased doublecortin positive neurons in the dorsal hippocampus, while chronic treatment with F13714 resulted in a downregulation of 5-HT1A autoreceptors, which likely reversed the acute impairment in OPS performance. Chronic treatment with NLX-101 appears to have therapeutic potential to improve brain plasticity and OPS performance.
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Affiliation(s)
- Britt T J van Hagen
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Nick P van Goethem
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Ellis Nelissen
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Dean Paes
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Karin Koymans
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands; Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, the Netherlands
| | - Scott van Hoof
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands; German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117 Berlin, Germany
| | - Rudy Schreiber
- Faculty of Psychology and Neuroscience, Section Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, the Netherlands
| | - Mark Varney
- Neurolixis Inc., Dana Point, California, USA
| | | | - Jos Prickaerts
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.
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17
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Jennen L, Mazereel V, Lecei A, Samaey C, Vancampfort D, van Winkel R. Exercise to spot the differences: a framework for the effect of exercise on hippocampal pattern separation in humans. Rev Neurosci 2022; 33:555-582. [PMID: 35172422 DOI: 10.1515/revneuro-2021-0156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/16/2022] [Indexed: 12/12/2022]
Abstract
Exercise has a beneficial effect on mental health and cognitive functioning, but the exact underlying mechanisms remain largely unknown. In this review, we focus on the effect of exercise on hippocampal pattern separation, which is a key component of episodic memory. Research has associated exercise with improvements in pattern separation. We propose an integrated framework mechanistically explaining this relationship. The framework is divided into three pathways, describing the pro-neuroplastic, anti-inflammatory and hormonal effects of exercise. The pathways are heavily intertwined and may result in functional and structural changes in the hippocampus. These changes can ultimately affect pattern separation through direct and indirect connections. The proposed framework might guide future research on the effect of exercise on pattern separation in the hippocampus.
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Affiliation(s)
- Lise Jennen
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium
| | - Victor Mazereel
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium.,University Psychiatric Center KU Leuven, Leuvensesteenweg 517, 3070 Leuven-Kortenberg, Belgium
| | - Aleksandra Lecei
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium
| | - Celine Samaey
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium
| | - Davy Vancampfort
- University Psychiatric Center KU Leuven, Leuvensesteenweg 517, 3070 Leuven-Kortenberg, Belgium.,KU Leuven Department of Rehabilitation Sciences, ON IV Herestraat 49, bus 1510, 3000, Leuven, Belgium
| | - Ruud van Winkel
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium.,University Psychiatric Center KU Leuven, Leuvensesteenweg 517, 3070 Leuven-Kortenberg, Belgium
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18
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Kay Y, Tsan L, Davis EA, Tian C, Décarie-Spain L, Sadybekov A, Pushkin AN, Katritch V, Kanoski SE, Herring BE. Schizophrenia-associated SAP97 mutations increase glutamatergic synapse strength in the dentate gyrus and impair contextual episodic memory in rats. Nat Commun 2022; 13:798. [PMID: 35145085 PMCID: PMC8831576 DOI: 10.1038/s41467-022-28430-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 01/05/2022] [Indexed: 12/24/2022] Open
Abstract
Mutations in the putative glutamatergic synapse scaffolding protein SAP97 are associated with the development of schizophrenia in humans. However, the role of SAP97 in synaptic regulation is unclear. Here we show that SAP97 is expressed in the dendrites of granule neurons in the dentate gyrus but not in the dendrites of other hippocampal neurons. Schizophrenia-related perturbations of SAP97 did not affect CA1 pyramidal neuron synapse function. Conversely, these perturbations produce dramatic augmentation of glutamatergic neurotransmission in granule neurons that can be attributed to a release of perisynaptic GluA1-containing AMPA receptors into the postsynaptic densities of perforant pathway synapses. Furthermore, inhibiting SAP97 function in the dentate gyrus was sufficient to impair contextual episodic memory. Together, our results identify a cell-type-specific synaptic regulatory mechanism in the dentate gyrus that, when disrupted, impairs contextual information processing in rats. The effects of SAP97 mutations associated with schizophrenia on synaptic function are unclear. Here, the authors show that schizophrenia-related SAP97 mutations enhance glutamatergic synapse strength in the dentate gyrus, impairing contextual episodic memory in rats.
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Affiliation(s)
- Yuni Kay
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA
| | - Linda Tsan
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA
| | - Elizabeth A Davis
- Department of Biological Sciences, Human and Evolutionary Biology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Chen Tian
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA
| | - Léa Décarie-Spain
- Department of Biological Sciences, Human and Evolutionary Biology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Anastasiia Sadybekov
- Department of Chemistry, University of Southern California, Los Angeles, CA, 90089, USA
| | - Anna N Pushkin
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA
| | - Vsevolod Katritch
- Department of Chemistry, University of Southern California, Los Angeles, CA, 90089, USA.,Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Scott E Kanoski
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA.,Department of Biological Sciences, Human and Evolutionary Biology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Bruce E Herring
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA. .,Department of Biological Sciences, Neurobiology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, 90089, USA.
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19
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Westacott LJ, Haan N, Evison C, Marei O, Hall J, Hughes TR, Zaben M, Morgan BP, Humby T, Wilkinson LS, Gray WP. Dissociable effects of complement C3 and C3aR on survival and morphology of adult born hippocampal neurons, pattern separation, and cognitive flexibility in male mice. Brain Behav Immun 2021; 98:136-150. [PMID: 34403734 DOI: 10.1016/j.bbi.2021.08.215] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/15/2021] [Accepted: 08/09/2021] [Indexed: 12/14/2022] Open
Abstract
Adult hippocampal neurogenesis (AHN) is a form of ongoing plasticity in the brain that supports specific aspects of cognition. Disruptions in AHN have been observed in neuropsychiatric conditions presenting with inflammatory components and are associated with impairments in cognition and mood. Recent evidence highlights important roles of the complement system in synaptic plasticity and neurogenesis during neurodevelopment and in acute learning and memory processes. In this work we investigated the impact of the complement C3/C3aR pathway on AHN and its functional implications for AHN-related behaviours. In C3-/- mice, we found increased numbers and accelerated migration of adult born granule cells, indicating that absence of C3 leads to abnormal survival and distribution of adult born neurons. Loss of either C3 or C3aR affected the morphology of immature neurons, reducing morphological complexity, though these effects were more pronounced in the absence of C3aR. We assessed functional impacts of the cellular phenotypes in an operant spatial discrimination task that assayed AHN sensitive behaviours. Again, we observed differences in the effects of manipulating C3 or C3aR, in that whilst C3aR-/- mice showed evidence of enhanced pattern separation abilities, C3-/- mice instead demonstrated impaired behavioural flexibility. Our findings show that C3 and C3aR manipulation have distinct effects on AHN that impact at different stages in the development and maturation of newly born neurons, and that the dissociable cellular phenotypes are associated with specific alterations in AHN-related behaviours.
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Affiliation(s)
- Laura J Westacott
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - Niels Haan
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - Claudia Evison
- National Centre for Mental Health, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK
| | - Omar Marei
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK
| | - Jeremy Hall
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - Timothy R Hughes
- Complement Biology Group, Systems Immunity Research Institute, School of Medicine, Cardiff University, CF14 4XW Cardiff, UK
| | - Malik Zaben
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Brain Repair and Intracranial Neurotherapeutics (BRAIN), Biomedical Research Unit, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, CF24 4HQ, UK
| | - B Paul Morgan
- Complement Biology Group, Systems Immunity Research Institute, School of Medicine, Cardiff University, CF14 4XW Cardiff, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK; UK Dementia Research Institute, Cardiff University, Cardiff CF24 4HQ, UK
| | - Trevor Humby
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Behavioural Genetics Group, Schools of Psychology and Medicine, Cardiff University, Cardiff CF10 3AT, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - Lawrence S Wilkinson
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Behavioural Genetics Group, Schools of Psychology and Medicine, Cardiff University, Cardiff CF10 3AT, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - William P Gray
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK; Brain Repair and Intracranial Neurotherapeutics (BRAIN), Biomedical Research Unit, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, CF24 4HQ, UK.
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20
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Mnemonic Discrimination Deficits in First-Episode Psychosis and a Ketamine Model Suggest Dentate Gyrus Pathology Linked to NMDA Receptor Hypofunction. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2021; 6:1185-1192. [PMID: 34649019 DOI: 10.1016/j.bpsc.2021.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/17/2021] [Accepted: 09/12/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Converging evidence from neuroimaging and postmortem studies suggests that hippocampal subfields are differentially affected in schizophrenia. Recent studies report dentate gyrus dysfunction in chronic schizophrenia, but the underlying mechanisms remain to be elucidated. Here, we sought to examine if this deficit is already present in first-episode psychosis and if NMDA receptor hypofunction, a putative central pathophysiological mechanism in schizophrenia, experimentally induced by ketamine, would result in a similar abnormality. METHODS We applied a mnemonic discrimination task selectively taxing pattern separation in two experiments: 1) a group of 23 patients with first-episode psychosis and 23 matched healthy volunteers and 2) a group of 19 healthy volunteers before and during a ketamine challenge (0.27 mg/kg over 10 min, then 0.25 mg/kg/hour for 50 min, 0.01 mL/s). We calculated response bias-corrected pattern separation and recognition scores. We also examined the relationships between task performance and symptom severity as well as ketamine levels. RESULTS We reported a deficit in pattern separation performance in patients with first-episode psychosis compared with healthy volunteers (p = .04) and in volunteers during the ketamine challenge compared with baseline (p = .003). Pattern recognition was lower in patients with first-episode psychosis than in control subjects (p < .01). Exploratory analyses revealed no correlation between task performance and Repeatable Battery for the Assessment of Neuropsychological Status total scores or positive symptoms in patients with first-episode psychosis or with ketamine serum levels. CONCLUSIONS We observed a mnemonic discrimination deficit in both datasets. Our findings suggest a tentative mechanistic link between dentate gyrus dysfunction in first-episode psychosis and NMDA receptor hypofunction.
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21
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Oulé M, Atucha E, Wells TM, Macharadze T, Sauvage MM, Kreutz MR, Lopez-Rojas J. Dendritic Kv4.2 potassium channels selectively mediate spatial pattern separation in the dentate gyrus. iScience 2021; 24:102876. [PMID: 34386734 PMCID: PMC8346659 DOI: 10.1016/j.isci.2021.102876] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/22/2021] [Accepted: 07/14/2021] [Indexed: 11/23/2022] Open
Abstract
The capacity to distinguish comparable experiences is fundamental for the recall of similar memories and has been proposed to require pattern separation in the dentate gyrus (DG). However, the cellular mechanisms by which mature granule cells (GCs) of the DG accomplish this function are poorly characterized. Here, we show that Kv4.2 channels selectively modulate the excitability of medial dendrites of dentate GCs. These dendrites are targeted by the medial entorhinal cortex, the main source of spatial inputs to the DG. Accordingly, we found that the spatial pattern separation capability of animals lacking the Kv4.2 channel is significantly impaired. This points to the role of intrinsic excitability in supporting the mnemonic function of the dentate and to the Kv4.2 channel as a candidate substrate promoting spatial pattern separation.
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Affiliation(s)
- Marie Oulé
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Erika Atucha
- Functional Architecture of Memory Department, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Tenyse M. Wells
- Functional Architecture of Memory Department, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Tamar Macharadze
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
- Department of Anesthesiology and Intensive Care Medicine, Otto-von-Guericke-University, 39120 Magdeburg, Germany
| | - Magdalena M. Sauvage
- Functional Architecture of Memory Department, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
- Otto von Guericke University, Medical Faculty, Functional Neuroplasticity Department, 39120, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106 Magdeburg, Germany
| | - Michael R. Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106 Magdeburg, Germany
- Leibniz Group 'Dendritic Organelles and Synaptic Function', University Medical Center Hamburg-Eppendorf, Center for Molecular Neurobiology (ZMNH), 20251 Hamburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| | - Jeffrey Lopez-Rojas
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106 Magdeburg, Germany
- Department of Neuroscience, The Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10027, USA
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22
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Rolls ET, Cheng W, Gilson M, Gong W, Deco G, Lo CYZ, Yang AC, Tsai SJ, Liu ME, Lin CP, Feng J. Beyond the disconnectivity hypothesis of schizophrenia. Cereb Cortex 2021; 30:1213-1233. [PMID: 31381086 DOI: 10.1093/cercor/bhz161] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 06/24/2019] [Accepted: 06/24/2019] [Indexed: 01/01/2023] Open
Abstract
To go beyond the disconnectivity hypothesis of schizophrenia, directed (effective) connectivity was measured between 94 brain regions, to provide evidence on the source of the changes in schizophrenia and a mechanistic model. Effective connectivity (EC) was measured in 180 participants with schizophrenia and 208 controls. For the significantly different effective connectivities in schizophrenia, on average the forward (stronger) effective connectivities were smaller, whereas the backward connectivities tended to be larger. Further, higher EC in schizophrenia was found from the precuneus and posterior cingulate cortex (PCC) to areas such as the parahippocampal, hippocampal, temporal, fusiform, and occipital cortices. These are backward effective connectivities and were positively correlated with the positive symptoms of schizophrenia. Lower effective connectivities were found from temporal and other regions and were negatively correlated with the symptoms, especially the negative and general symptoms. Further, a signal variance parameter was increased for areas that included the parahippocampal gyrus and hippocampus, consistent with the hypothesis that hippocampal overactivity is involved in schizophrenia. This investigation goes beyond the disconnectivity hypothesis by drawing attention to differences in schizophrenia between backprojections and forward connections, with the backward connections from the precuneus and PCC implicated in memory stronger in schizophrenia.
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Affiliation(s)
- Edmund T Rolls
- Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, 200433, PR China.,Department of Computer Science, University of Warwick, Coventry CV4 7AL, UK.,Oxford Centre for Computational Neuroscience, Oxford OX1 4BH, UK
| | - Wei Cheng
- Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, 200433, PR China.,Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence (Fudan University), Ministry of Education, 200433, China
| | - Matthieu Gilson
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Roc Boronat 138, Barcelona E-08018, Spain and Brain and Cognition, Pompeu Fabra University, Barcelona, Spain
| | - Weikang Gong
- Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, OX1 4BH, UK
| | - Gustavo Deco
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Roc Boronat 138, Barcelona E-08018, Spain and Brain and Cognition, Pompeu Fabra University, Barcelona, Spain.,Institució Catalana de la Recerca i Estudis Avançats (ICREA), Universitat Pompeu Fabra, Passeig Lluís Companys 23, Barcelona, 08010, Spain
| | - Chun-Yi Zac Lo
- Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, 200433, PR China
| | - Albert C Yang
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei 11267, Taiwan
| | - Shih-Jen Tsai
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei 11267, Taiwan
| | - Mu-En Liu
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei 11267, Taiwan
| | - Ching-Po Lin
- Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, 200433, PR China.,Institute of Neuroscience, National Yang-Ming University, Taipei 11221, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei 11221, Taiwan
| | - Jianfeng Feng
- Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, 200433, PR China.,Department of Computer Science, University of Warwick, Coventry CV4 7AL, UK.,School of Mathematical Sciences, School of Life Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200433, PR China.,Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence (Fudan University), Ministry of Education, 200433, China
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23
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Haan N, Westacott LJ, Carter J, Owen MJ, Gray WP, Hall J, Wilkinson LS. Haploinsufficiency of the schizophrenia and autism risk gene Cyfip1 causes abnormal postnatal hippocampal neurogenesis through microglial and Arp2/3 mediated actin dependent mechanisms. Transl Psychiatry 2021; 11:313. [PMID: 34031371 PMCID: PMC8144403 DOI: 10.1038/s41398-021-01415-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 04/21/2021] [Accepted: 05/04/2021] [Indexed: 12/12/2022] Open
Abstract
Genetic risk factors can significantly increase chances of developing psychiatric disorders, but the underlying biological processes through which this risk is effected remain largely unknown. Here we show that haploinsufficiency of Cyfip1, a candidate risk gene present in the pathogenic 15q11.2(BP1-BP2) deletion may impact on psychopathology via abnormalities in cell survival and migration of newborn neurons during postnatal hippocampal neurogenesis. We demonstrate that haploinsufficiency of Cyfip1 leads to increased numbers of adult-born hippocampal neurons due to reduced apoptosis, without altering proliferation. We show this is due to a cell autonomous failure of microglia to induce apoptosis through the secretion of the appropriate factors, a previously undescribed mechanism. Furthermore, we show an abnormal migration of adult-born neurons due to altered Arp2/3 mediated actin dynamics. Together, our findings throw new light on how the genetic risk candidate Cyfip1 may influence the hippocampus, a brain region with strong evidence for involvement in psychopathology.
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Affiliation(s)
- Niels Haan
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK.
| | - Laura J Westacott
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - Jenny Carter
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - Michael J Owen
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - William P Gray
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- Brain Repair and Intercranial Neurotherapeutics Unit, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- Hodge Centre for Neuropsychiatric Immunology, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - Jeremy Hall
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- Hodge Centre for Neuropsychiatric Immunology, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - Lawrence S Wilkinson
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- Hodge Centre for Neuropsychiatric Immunology, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- School of Psychology, Cardiff University, Tower Building, Cardiff, UK
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24
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Gordon A, Forsingdal A, Klewe IV, Nielsen J, Didriksen M, Werge T, Geschwind DH. Transcriptomic networks implicate neuronal energetic abnormalities in three mouse models harboring autism and schizophrenia-associated mutations. Mol Psychiatry 2021; 26:1520-1534. [PMID: 31705054 DOI: 10.1038/s41380-019-0576-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 09/17/2019] [Accepted: 10/23/2019] [Indexed: 12/12/2022]
Abstract
Genetic risk for psychiatric illness is complex, so identification of shared molecular pathways where distinct forms of genetic risk might coincide is of substantial interest. A growing body of genetic and genomic studies suggest that such shared molecular pathways exist across disorders with different clinical presentations, such as schizophrenia and autism spectrum disorder (ASD). But how this relates to specific genetic risk factors is unknown. Further, whether some of the molecular changes identified in brain relate to potentially confounding antemortem or postmortem factors are difficult to prove. We analyzed the transcriptome from the cortex and hippocampus of three mouse lines modeling human copy number variants (CNVs) associated with schizophrenia and ASD: Df(h15q13)/+, Df(h22q11)/+, and Df(h1q21)/+ which carry the 15q13.3 deletion, 22q11.2 deletion, and 1q21.1 deletion, respectively. Although we found very little overlap of differential expression at the level of individual genes, gene network analysis identified two cortical and two hippocampal modules of co-expressed genes that were dysregulated across all three mouse models. One cortical module was associated with neuronal energetics and firing rate, and overlapped with changes identified in postmortem human brain from SCZ and ASD patients. These data highlight aspects of convergent gene expression in mouse models harboring major risk alleles, and strengthen the connection between changes in neuronal energetics and neuropsychiatric disorders in humans.
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Affiliation(s)
- Aaron Gordon
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA
| | - Annika Forsingdal
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark.,Institute of Biological Psychiatry, Mental Health Services Capital Region of Denmark, Copenhagen, Denmark
| | | | - Jacob Nielsen
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark
| | | | - Thomas Werge
- Institute of Biological Psychiatry, Mental Health Services Capital Region of Denmark, Copenhagen, Denmark. .,Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Copenhagen, Denmark. .,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. .,Lundbeck Foundation GeoGenetics Centre, Natural History Museum of Denmark, University of Copenhagen, 1350, Copenhagen, Denmark.
| | - Daniel H Geschwind
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA. .,Program in Neurobehavioral Genetics, Semel Institute, David Geffen School of Medicine, University of California, Los Angeles, CA, USA. .,Center for Autism Research and Treatment, Semel Institute, David Geffen School of Medicine, University of California, Los Angeles, CA, USA. .,Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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25
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Keeler J, Lambert E, Olivola M, Owen J, Xia J, Thuret S, Himmerich H, Cardi V, Treasure J. Lower pattern recognition memory scores in anorexia nervosa. J Eat Disord 2021; 9:49. [PMID: 33865451 PMCID: PMC8052530 DOI: 10.1186/s40337-021-00406-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/07/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is extensive evidence for volumetric reductions in the hippocampus in patients with anorexia nervosa (AN), however the impact on function is unclear. Pattern separation and recognition are hippocampus-dependent forms of learning thought to underlie stimulus discrimination. METHODS The present study used the Mnemonic Similarity Task to investigate pattern separation and recognition for the first time in patients with AN (N = 46) and healthy controls (N = 56). An Analysis of Covariance examined between-group differences, controlling for age, antidepressant use and method of task delivery (remote vs. in person). RESULTS When controlling for covariates, pattern recognition memory scores were lower in the AN group with a medium effect size (d = 0.51). In contrast, there was a small effect whereby patients with AN had a greater pattern separation score than controls (d = 0.34), albeit this difference was not significant at the p = 0.05 threshold (p = 0.133). Furthermore, pattern separation and recognition memory abilities were not related to age, body mass index, eating disorder psychopathology or trait anxiety levels. CONCLUSIONS This preliminary study provides initial evidence for an imbalance in pattern separation and recognition abilities in AN, a hippocampus-dependent cognitive ability. Further studies should endeavour to investigate pattern separation and recognition performance further in AN, as well as investigate other hippocampus-dependent functions.
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Affiliation(s)
- Johanna Keeler
- Section of Eating Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 103 Denmark Hill, London, SE5 8AF, UK.
| | - Ellen Lambert
- Section of Eating Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 103 Denmark Hill, London, SE5 8AF, UK
| | - Miriam Olivola
- Section of Eating Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 103 Denmark Hill, London, SE5 8AF, UK
- Department of Mental Health and Addictions, Azienda Socio-Sanitaria Territoriale di Pavia, Pavia, Italy
| | - Judith Owen
- Section of Eating Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 103 Denmark Hill, London, SE5 8AF, UK
| | - Jingjing Xia
- Section of Eating Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 103 Denmark Hill, London, SE5 8AF, UK
| | - Sandrine Thuret
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Hubertus Himmerich
- Section of Eating Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 103 Denmark Hill, London, SE5 8AF, UK
| | - Valentina Cardi
- Section of Eating Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 103 Denmark Hill, London, SE5 8AF, UK
- Department of General Psychology, University of Padova, Padova, Italy
| | - Janet Treasure
- Section of Eating Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 103 Denmark Hill, London, SE5 8AF, UK
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26
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Mancini V, Sandini C, Padula MC, Zöller D, Schneider M, Schaer M, Eliez S. Positive psychotic symptoms are associated with divergent developmental trajectories of hippocampal volume during late adolescence in patients with 22q11DS. Mol Psychiatry 2020; 25:2844-2859. [PMID: 31164700 DOI: 10.1038/s41380-019-0443-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 05/04/2019] [Accepted: 05/13/2019] [Indexed: 12/17/2022]
Abstract
Low hippocampal volume is a consistent finding in schizophrenia and across the psychosis spectrum. However, there is a lack of studies investigating longitudinal hippocampal development and its relationship with psychotic symptoms. The 22q11.2 deletion syndrome (22q11DS) has proven to be a remarkable model for the prospective study of individuals at high risk of schizophrenia to unravel the pathophysiological processes predating the onset of psychosis. Repeated cerebral MRIs were acquired from 140 patients with 22q11DS (53 experiencing moderate-to-severe psychotic symptoms) and 135 healthy controls aged from 6 to 35 years and with up to 5 time points per participant. Hippocampal subfield analysis was conducted using FreeSurfer-v.6 and FIRST-FSL. Then, whole hippocampal and subfield volumes were compared across the groups. Relative to controls, patients with 22q11DS showed a remarkably lower volume of all subfields except for CA2/3. No divergent trajectories in hippocampal development were found. When comparing patients with 22q11DS exhibiting psychotic symptoms to those without psychosis, we detected a volume decrease during late adolescence, starting in CA1 and spreading to other subfields. Our findings suggested that hippocampal volume is consistently smaller in patients with 22q11DS. Moreover, we have demonstrated that patients with 22q11DS and psychotic symptoms undergo a further decrease in volume during adolescence, a vulnerable period for the emergence of psychosis. Interestingly, CA2/3, despite being affected in patients with psychotic symptoms, was the only area not reduced in patients with 22q11DS relative to controls, thus suggesting that its atrophy exclusively correlates with the presence of positive psychotic symptoms.
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Affiliation(s)
- Valentina Mancini
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland.
| | - Corrado Sandini
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland
| | - Maria C Padula
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland.,Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Daniela Zöller
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland.,Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Maude Schneider
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland.,Department of Neuroscience, Center for Contextual Psychiatry, Research Group Psychiatry, KU Leuven, Leuven, Belgium
| | - Marie Schaer
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland
| | - Stephan Eliez
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland.,Department of Genetic Medicine and Development, University of Geneva School of Medicine, Geneva, Switzerland
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27
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Pajkossy P, Szőllősi Á, Racsmány M. Pupil size changes signal hippocampus-related memory functions. Sci Rep 2020; 10:16393. [PMID: 33009460 PMCID: PMC7532445 DOI: 10.1038/s41598-020-73374-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 09/14/2020] [Indexed: 11/08/2022] Open
Abstract
A major task of episodic memory is to create unique, distinguishable representations of highly overlapping perceptual inputs. Several studies on this basic function have shown that it is based on the intact functioning of certain subregions of the hippocampus and is among the most sensitive behavioral indicators of mild cognitive impairment (MCI) and dementia. Here we assessed pupil dilation associated with performance in a widely used recognition paradigm that aims to uncover the intactness of fine-graded mnemonic discrimination. A sample of healthy undergraduate students was used. First, we showed that the correct discrimination between highly similar lure items and target items elicit larger pupil response than correct target identification. Second, we found that mnemonic discrimination is associated with larger pupil response in general as compared to target identification, regardless of whether the response was correct or not. These results suggest the pupil changes differentiate mnemonic discrimination and memory identification processes in recognition performance.
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Affiliation(s)
- Péter Pajkossy
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary.
- Department of Cognitive Science, Budapest University of Technology and Economics, Egry József u. 1, 1111, Budapest, Hungary.
| | - Ágnes Szőllősi
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
- Department of Cognitive Science, Budapest University of Technology and Economics, Egry József u. 1, 1111, Budapest, Hungary
| | - Mihály Racsmány
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
- Department of Cognitive Science, Budapest University of Technology and Economics, Egry József u. 1, 1111, Budapest, Hungary
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28
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Sahakyan L, Meller T, Evermann U, Schmitt S, Pfarr JK, Sommer J, Kwapil TR, Nenadić I. Anterior vs Posterior Hippocampal Subfields in an Extended Psychosis Phenotype of Multidimensional Schizotypy in a Nonclinical Sample. Schizophr Bull 2020; 47:207-218. [PMID: 32691055 PMCID: PMC8208318 DOI: 10.1093/schbul/sbaa099] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Numerous studies have implicated involvement of the hippocampus in the etiology and expression of schizophrenia-spectrum psychopathology, and reduced hippocampal volume is one of the most robust brain abnormalities reported in schizophrenia. Recent studies indicate that early stages of schizophrenia are specifically characterized by reductions in anterior hippocampal volume; however, studies have not examined hippocampal volume reductions in subclinical schizotypy. The present study was the first to examine the associations of positive, negative, and disorganized schizotypy dimensions with hippocampal subfield volumes in a large sample (n = 195) of nonclinically ascertained young adults, phenotyped using the Multidimensional Schizotypy Scale (MSS). Hippocampal subfields were analyzed from high-resolution 3 Tesla structural magnetic resonance imaging scans testing anatomical models, including anterior vs posterior regions and the cornu ammonis (CA), dentate gyrus (DG), and subiculum subfields separately for the left and right hemispheres. We demonstrate differential spatial effects across anterior vs posterior hippocampus segments across different dimensions of the schizotypy risk phenotype. The interaction of negative and disorganized schizotypy robustly predicted left hemisphere volumetric reductions for the anterior and total hippocampus, and anterior CA and DG, and the largest reductions were seen in participants high in negative and disorganized schizotypy. These findings extend previous early psychosis studies and together with behavioral studies of hippocampal-related memory impairments provide the basis for a dimensional neurobiological hippocampal model of schizophrenia risk. Subtle hippocampal subfield volume reductions may be prevalent prior to the onset of detectable prodromal clinical symptoms of psychosis and play a role in the etiology and development of such conditions.
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Affiliation(s)
- Lili Sahakyan
- Department of Psychology and Beckman Institute for Advanced Science and
Technology, University of Illinois, Champaign, IL
| | - Tina Meller
- Cognitive Neuropsychiatry Lab, Department of Psychiatry and Psychotherapy,
Philipps-University Marburg, Marburg, Germany,Center for Mind, Brain, and Behavior (CMBB), Marburg, Germany
| | - Ulrika Evermann
- Cognitive Neuropsychiatry Lab, Department of Psychiatry and Psychotherapy,
Philipps-University Marburg, Marburg, Germany,Center for Mind, Brain, and Behavior (CMBB), Marburg, Germany
| | - Simon Schmitt
- Cognitive Neuropsychiatry Lab, Department of Psychiatry and Psychotherapy,
Philipps-University Marburg, Marburg, Germany,Center for Mind, Brain, and Behavior (CMBB), Marburg, Germany
| | - Julia-Katharina Pfarr
- Cognitive Neuropsychiatry Lab, Department of Psychiatry and Psychotherapy,
Philipps-University Marburg, Marburg, Germany,Center for Mind, Brain, and Behavior (CMBB), Marburg, Germany
| | - Jens Sommer
- Core Facility BrainImaging, School of Medicine, Philipps-University
Marburg, Marburg, Germany
| | - Thomas R Kwapil
- Department of Psychology and Beckman Institute for Advanced Science and
Technology, University of Illinois, Champaign, IL
| | - Igor Nenadić
- Cognitive Neuropsychiatry Lab, Department of Psychiatry and Psychotherapy,
Philipps-University Marburg, Marburg, Germany,Center for Mind, Brain, and Behavior (CMBB), Marburg, Germany,To whom correspondence should be addressed; Department of Psychiatry and
Psychotherapy, Philipps-University Marburg, Rudolf-Bultmann-Str. 8, 35039 Marburg,
Germany; tel: +49-6421-58-65002, fax: +49-6421-58-68939, e-mail:
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29
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Das T, Kim N, McDaniel C, Poston KL. Mnemonic Similarity Task to study episodic memory in Parkinson's disease. Clin Park Relat Disord 2020; 3:100062. [PMID: 34316643 PMCID: PMC8298797 DOI: 10.1016/j.prdoa.2020.100062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/10/2020] [Accepted: 06/02/2020] [Indexed: 11/22/2022] Open
Abstract
Introduction Parkinson's disease (PD) patients commonly experience episodic memory impairments, which are associated with an increased risk of dementia. The Mnemonic Similarity Task (MST) is a well-validated test to investigate episodic memory changes in healthy aging and in neurodegenerative diseases but has not been studied in PD patients. Methods In the MST task, participants respond during a testing phase whether visualized images are “repeat”, “similar”, or “new”, compared to images previously shown during an encoding phase. We tested 17 PD without cognitive impairment (level-II criteria), both off (PD-OFF) and on (PD-ON) dopaminergic medications; and compared PD-OFF with 17 age- and education-matched healthy controls (HC). Results We found no influence of dopaminergic medications nor of disease on MST reaction time for any responses (“repeat”, “similar”, and “new”) during the test phase. However, response probabilities showed that the MST is sensitive to subtle PD-related memory impairments. Specifically, PD-OFF responded more frequently with ‘repeat’, instead of ‘similar’ during lure trials, compared to HC (p = 0.030). This finding was still significant after correcting for response bias using the Recognition Index (p = 0.005). Conclusions PD patients perform the MST without interference from bradykinesia or other PD-related motor symptoms. Our findings suggest that PD patients who do not meet criteria for mild cognitive impairment can have subtle recall or recognition impairments, which can be identified using the MST. We propose the MST as a well-tolerated and sensitive cognitive task in future studies of episodic memory impairment and progressive memory dysfunction in people with PD. Cognitively normal PD performs the MST similarly to controls despite motor symptoms. Dopaminergic medications do not interfere with MST task performance in PD. The MST is robust and able to discern subtle episodic memory changes in PD.
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Affiliation(s)
- Tanusree Das
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Nessa Kim
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Colin McDaniel
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Kathleen L. Poston
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
- Corresponding author at: Stanford University School of Medicine, 780 Welch Road, CJ350C, Palo Alto, CA 94304, USA.
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30
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Lucassen PJ, Fitzsimons CP, Salta E, Maletic-Savatic M. Adult neurogenesis, human after all (again): Classic, optimized, and future approaches. Behav Brain Res 2020; 381:112458. [DOI: 10.1016/j.bbr.2019.112458] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 11/29/2019] [Accepted: 12/28/2019] [Indexed: 02/08/2023]
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31
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Segev A, Yanagi M, Scott D, Southcott SA, Lister JM, Tan C, Li W, Birnbaum SG, Kourrich S, Tamminga CA. Reduced GluN1 in mouse dentate gyrus is associated with CA3 hyperactivity and psychosis-like behaviors. Mol Psychiatry 2020; 25:2832-2843. [PMID: 30038231 PMCID: PMC6344327 DOI: 10.1038/s41380-018-0124-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 10/30/2017] [Accepted: 01/15/2018] [Indexed: 01/07/2023]
Abstract
Recent findings from in vivo-imaging and human post-mortem tissue studies in schizophrenic psychosis (SzP), have demonstrated functional and molecular changes in hippocampal subfields that can be associated with hippocampal hyperexcitability. In this study, we used a subfield-specific GluN1 knockout mouse with a disease-like molecular perturbation expressed only in hippocampal dentate gyrus (DG) and assessed its association with hippocampal physiology and psychosis-like behaviors. First, we used whole-cell patch-clamp recordings to measure the physiological changes in hippocampal subfields and cFos immunohistochemistry to examine cellular excitability. DG-GluN1 KO mice show CA3 cellular hyperactivity, detected using two approaches: (1) increased excitatory glutamate transmission at mossy fibers (MF)-CA3 synapses, and (2) an increased number of cFos-activated pyramidal neurons in CA3, an outcome that appears to project downstream to CA1 and basolateral amygdala (BLA). Furthermore, we examined psychosis-like behaviors and pathological memory processing; these show an increase in fear conditioning (FC), a reduction in prepulse inhibition (PPI) in the KO animal, along with a deterioration in memory accuracy with Morris Water Maze (MWM) and reduced social memory (SM). Moreover, with DREADD vectors, we demonstrate a remarkably similar behavioral profile when we induce CA3 hyperactivity. These hippocampal subfield changes could provide the basis for the observed increase in human hippocampal activity in SzP, based on the shared DG-specific GluN1 reduction. With further characterization, these animal model systems may serve as targets to test psychosis mechanisms related to hippocampus and assess potential hippocampus-directed treatments.
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Affiliation(s)
- Amir Segev
- grid.267313.20000 0000 9482 7121Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390 USA
| | - Masaya Yanagi
- grid.267313.20000 0000 9482 7121Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390 USA ,grid.258622.90000 0004 1936 9967Present Address: Department of Neuropsychiatry, Kindai University Faculty of Medicine, Osaka, Japan
| | - Daniel Scott
- grid.267313.20000 0000 9482 7121Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390 USA
| | - Sarah A. Southcott
- grid.267313.20000 0000 9482 7121Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390 USA
| | - Jacob M. Lister
- grid.267313.20000 0000 9482 7121Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390 USA ,grid.47100.320000000419368710Yale University, School of Medicine, 333 Cedar Street, New Haven, CT 06510 USA ,grid.47100.320000000419368710Present Address: Yale University, School of Medicine, New Haven, CT USA
| | - Chunfeng Tan
- grid.267313.20000 0000 9482 7121Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390 USA
| | - Wei Li
- grid.267313.20000 0000 9482 7121Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390 USA
| | - Shari G. Birnbaum
- grid.267313.20000 0000 9482 7121Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390 USA
| | - Saïd Kourrich
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, 75390, USA.
| | - Carol A. Tamminga
- grid.267313.20000 0000 9482 7121Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390 USA
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32
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Raabe FJ, Slapakova L, Rossner MJ, Cantuti-Castelvetri L, Simons M, Falkai PG, Schmitt A. Oligodendrocytes as A New Therapeutic Target in Schizophrenia: From Histopathological Findings to Neuron-Oligodendrocyte Interaction. Cells 2019; 8:cells8121496. [PMID: 31771166 PMCID: PMC6952785 DOI: 10.3390/cells8121496] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/20/2019] [Accepted: 11/21/2019] [Indexed: 12/11/2022] Open
Abstract
Imaging and postmortem studies have revealed disturbed oligodendroglia-related processes in patients with schizophrenia and provided much evidence for disturbed myelination, irregular gene expression, and altered numbers of oligodendrocytes in the brains of schizophrenia patients. Oligodendrocyte deficits in schizophrenia might be a result of failed maturation and disturbed regeneration and may underlie the cognitive deficits of the disease, which are strongly associated with impaired long-term outcome. Cognition depends on the coordinated activity of neurons and interneurons and intact connectivity. Oligodendrocyte precursors form a synaptic network with parvalbuminergic interneurons, and disturbed crosstalk between these cells may be a cellular basis of pathology in schizophrenia. However, very little is known about the exact axon-glial cellular and molecular processes that may be disturbed in schizophrenia. Until now, investigations were restricted to peripheral tissues, such as blood, correlative imaging studies, genetics, and molecular and histological analyses of postmortem brain samples. The advent of human-induced pluripotent stem cells (hiPSCs) will enable functional analysis in patient-derived living cells and holds great potential for understanding the molecular mechanisms of disturbed oligodendroglial function in schizophrenia. Targeting such mechanisms may contribute to new treatment strategies for previously treatment-resistant cognitive symptoms.
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Affiliation(s)
- Florian J. Raabe
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Nussbaumstrasse 7, 80336 Munich, Germany; (F.J.R.); (L.S.); (P.G.F.)
- International Max Planck Research School for Translational Psychiatry (IMPRS-TP), Kraepelinstr, 2-10, 80804 Munich, Germany
- Molecular and Behavioural Neurobiology, Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, 80336 Munich, Germany;
| | - Lenka Slapakova
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Nussbaumstrasse 7, 80336 Munich, Germany; (F.J.R.); (L.S.); (P.G.F.)
- International Max Planck Research School for Translational Psychiatry (IMPRS-TP), Kraepelinstr, 2-10, 80804 Munich, Germany
| | - Moritz J. Rossner
- Molecular and Behavioural Neurobiology, Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, 80336 Munich, Germany;
| | - Ludovico Cantuti-Castelvetri
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377 Munich, Germany; (L.C.-C.); (M.S.)
| | - Mikael Simons
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377 Munich, Germany; (L.C.-C.); (M.S.)
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Institute of Neuronal Cell Biology, Technical University Munich, 80805 Munich, Germany
| | - Peter G. Falkai
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Nussbaumstrasse 7, 80336 Munich, Germany; (F.J.R.); (L.S.); (P.G.F.)
| | - Andrea Schmitt
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Nussbaumstrasse 7, 80336 Munich, Germany; (F.J.R.); (L.S.); (P.G.F.)
- Molecular and Behavioural Neurobiology, Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, 80336 Munich, Germany;
- Laboratory of Neuroscience (LIM27), Institute of Psychiatry, University of Sao Paulo, 05453-010 São Paulo, Brazil
- Correspondence: ; Tel.: +49-(0)89-4400-52761; Fax: +49-(0)89-4400-55530
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Stark SM, Kirwan CB, Stark CEL. Mnemonic Similarity Task: A Tool for Assessing Hippocampal Integrity. Trends Cogn Sci 2019; 23:938-951. [PMID: 31597601 DOI: 10.1016/j.tics.2019.08.003] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 12/25/2022]
Abstract
The hippocampus is critical for learning and memory, relying in part on pattern separation processes supported by the dentate gyrus (DG) to prevent interference from overlapping memory representations. In 2007, we designed the Mnemonic Similarity Task (MST), a modified object recognition memory task, to be highly sensitive to hippocampal function by placing strong demands on pattern separation. The MST is now a widely used behavioral task, repeatedly shown to be sensitive to age-related memory decline, hippocampal connectivity, and hippocampal function, with specificity to the DG. Here, we review the utility of the MST, its relationship to hippocampal function, its utility in detecting hippocampal-based memory alterations across the lifespan, and impairments associated with clinical pathology from a variety of disorders.
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Affiliation(s)
- Shauna M Stark
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - C Brock Kirwan
- Department of Psychology, Neuroscience Center, Brigham Young University, Provo, UT, USA
| | - Craig E L Stark
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA.
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Krajcovic B, Fajnerova I, Horacek J, Kelemen E, Kubik S, Svoboda J, Stuchlik A. Neural and neuronal discoordination in schizophrenia: From ensembles through networks to symptoms. Acta Physiol (Oxf) 2019; 226:e13282. [PMID: 31002202 DOI: 10.1111/apha.13282] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/27/2019] [Accepted: 04/12/2019] [Indexed: 12/22/2022]
Abstract
Despite the substantial knowledge accumulated by past research, the exact mechanisms of the pathogenesis of schizophrenia and causal treatments still remain unclear. Deficits of cognition and information processing in schizophrenia are today often viewed as the primary and core symptoms of this devastating disorder. These deficits likely result from disruptions in the coordination of neuronal and neural activity. The aim of this review is to bring together convergent evidence of discoordinated brain circuits in schizophrenia at multiple levels of resolution, ranging from principal cells and interneurons, neuronal ensembles and local circuits, to large-scale brain networks. We show how these aberrations could underlie deficits in cognitive control and other higher order cognitive-behavioural functions. Converging evidence from both animal models and patients with schizophrenia is presented in an effort to gain insight into common features of deficits in the brain information processing in this disorder, marked by disruption of several neurotransmitter and signalling systems and severe behavioural outcomes.
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Affiliation(s)
- Branislav Krajcovic
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
- Third Faculty of Medicine Charles University Prague Czech Republic
| | - Iveta Fajnerova
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
- Research Programme 3 - Applied Neurosciences and Brain Imaging National Institute of Mental Health Klecany Czech Republic
| | - Jiri Horacek
- Third Faculty of Medicine Charles University Prague Czech Republic
- Research Programme 3 - Applied Neurosciences and Brain Imaging National Institute of Mental Health Klecany Czech Republic
| | - Eduard Kelemen
- Research Programme 1 - Experimental Neurobiology National Institute of Mental Health Klecany Czech Republic
| | - Stepan Kubik
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Jan Svoboda
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Ales Stuchlik
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
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Argyrousi EK, de Nijs L, Lagatta DC, Schlütter A, Weidner MT, Zöller J, van Goethem NP, Joca SR, van den Hove DL, Prickaerts J. Effects of DNA methyltransferase inhibition on pattern separation performance in mice. Neurobiol Learn Mem 2019; 159:6-15. [DOI: 10.1016/j.nlm.2019.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 01/27/2019] [Accepted: 02/02/2019] [Indexed: 10/27/2022]
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Abstract
Hippocampal abnormalities have been heavily implicated in the pathophysiology of schizophrenia. The dentate gyrus of the hippocampus was shown to manifest an immature molecular profile in schizophrenia subjects, as well as in various animal models of the disorder. In this position paper, we advance a hypothesis that this immature molecular profile is accompanied by an identifiable immature morphology of the dentate gyrus granule cell layer. We adduce evidence for arrested maturation of the dentate gyrus in the human schizophrenia-affected brain, as well as multiple rodent models of the disease. Implications of this neurohistopathological signature for current theory regarding the development of schizophrenia are discussed.
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Affiliation(s)
- Ayda Tavitian
- Department of Neurology & Neurosurgery, Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Wei Song
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Hyman M. Schipper
- Department of Neurology & Neurosurgery, Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
- Department of Medicine, McGill University, Montreal, Quebec, Canada
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Zhou D, Liu S, Zhou X, Berman R, Broadnax D, Gochman P, Rapoport J, Thomas A. 7 T MRI reveals hippocampal structural abnormalities associated with memory intrusions in childhood-onset schizophrenia. Schizophr Res 2018; 202:431-432. [PMID: 30029830 PMCID: PMC6289865 DOI: 10.1016/j.schres.2018.07.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 05/09/2018] [Accepted: 07/13/2018] [Indexed: 11/25/2022]
Affiliation(s)
- Dale Zhou
- Section on Childhood Neuropsychiatric Disorders, Child Psychiatry Branch, National Institute of Mental Health, United States of America.
| | - Siyuan Liu
- Section on Childhood Neuropsychiatric Disorders, Child Psychiatry Branch, National Institute of Mental Health, United States of America
| | - Xueping Zhou
- Section on Childhood Neuropsychiatric Disorders, Child Psychiatry Branch, National Institute of Mental Health, United States of America
| | - Rebecca Berman
- Section on Cognitive Neurophysiology and Imaging, Laboratory of Neuropsychology, National Institute of Mental Health
| | - Diane Broadnax
- Section on Childhood Neuropsychiatric Disorders, Child Psychiatry Branch, National Institute of Mental Health, United States of America
| | - Peter Gochman
- Section on Childhood Neuropsychiatric Disorders, Child Psychiatry Branch, National Institute of Mental Health, United States of America
| | - Judith Rapoport
- Section on Childhood Neuropsychiatric Disorders, Child Psychiatry Branch, National Institute of Mental Health, United States of America
| | - Adam Thomas
- Data Science and Sharing Team, Center for Multimodal Neuroimaging, National Institute of Mental Health, United States of America,Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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Graf R, Longo JL, Hughes ZA. The location discrimination reversal task in mice is sensitive to deficits in performance caused by aging, pharmacological and other challenges. J Psychopharmacol 2018; 32:1027-1036. [PMID: 29897000 DOI: 10.1177/0269881118779383] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Deficits in hippocampal-mediated pattern separation are one aspect of cognitive function affected in schizophrenia (SZ) or Alzheimer's disease (AD). To develop novel therapies, it is beneficial to explore this specific aspect of cognition preclinically. The location discrimination reversal (LDR) task is a hippocampal-dependent operant paradigm that evaluates spatial learning and cognitive flexibility using touchscreens. Here we assessed baseline performance as well as multimodal disease-relevant manipulations in mice. Mice were trained to discriminate between the locations of two images where the degree of separation impacted performance. Administration of putative pro-cognitive agents was unable to improve performance at narrow separation. Furthermore, a range of disease-relevant manipulations were characterized to assess whether performance could be impaired and restored. Pertinent to the cholinergic loss in AD, scopolamine (0.1 mg/kg) produced a disruption in LDR, which was attenuated by donepezil (1 mg/kg). Consistent with NMDA hypofunction in cognitive impairment associated with SZ, MK-801 (0.1 mg/kg) also disrupted performance; however, this deficit was not modified by rolipram. Microdeletion of genes associated with SZ (22q11) resulted in impaired performance, which was restored by rolipram (0.032 mg/kg). Since aging and inflammation affect cognition and are risk factors for AD, these aspects were also evaluated. Aged mice were slower to acquire the task than young mice and did not reach the same level of performance. A systemic inflammatory challenge (lipopolysaccharide (LPS), 1 mg/kg) produced prolonged (7 days) deficits in the LDR task. These data suggest that LDR task is a valuable platform for evaluating disease-relevant deficits in pattern separation and offers potential for identifying novel therapies.
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Affiliation(s)
- Radka Graf
- Pfizer Internal Medicine Research Unit, Cambridge, MA, USA
| | - Jami L Longo
- Pfizer Internal Medicine Research Unit, Cambridge, MA, USA
| | - Zoë A Hughes
- Pfizer Internal Medicine Research Unit, Cambridge, MA, USA
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Miranda M, Kent BA, Morici JF, Gallo F, Saksida LM, Bussey TJ, Weisstaub N, Bekinschtein P. NMDA receptors and BDNF are necessary for discrimination of overlapping spatial and non-spatial memories in perirhinal cortex and hippocampus. Neurobiol Learn Mem 2018; 155:337-343. [PMID: 30172952 DOI: 10.1016/j.nlm.2018.08.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/03/2018] [Accepted: 08/29/2018] [Indexed: 01/06/2023]
Abstract
Successful memory involves not only remembering information over time but also keeping memories distinct and less confusable. Discrimination of overlapping representations has been investigated in the dentate gyrus (DG) of the hippocampus and largely in the perirhinal cortex (Prh). In particular, the DG was shown to be important for discrimination of overlapping spatial memories and Prh was shown to be important for discrimination of overlapping object memories. In the present study, we used both a DG-dependent and a Prh-dependent task and manipulated the load of similarity between either spatial or object stimuli during information encoding. We showed that N-methyl-D-aspartate-type glutamate receptors (NMDAr) and BDNF participate of the same cellular network during consolidation of both overlapping object and spatial memories in the Prh and DG, respectively. This argues in favor of conserved cellular mechanisms across regions despite anatomical differences.
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Affiliation(s)
- Magdalena Miranda
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina
| | - Brianne A Kent
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Juan Facundo Morici
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina
| | - Francisco Gallo
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina
| | - Lisa M Saksida
- Department of Psychology and MRC/Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK; Molecular Medicine Research Laboratories, Robarts Research Institute, Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; The Brain and Mind Institute, Western University, London, ON, Canada
| | - Timothy J Bussey
- Department of Psychology and MRC/Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK; Molecular Medicine Research Laboratories, Robarts Research Institute, Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; The Brain and Mind Institute, Western University, London, ON, Canada
| | - Noelia Weisstaub
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina
| | - Pedro Bekinschtein
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina.
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Assessing spatial pattern separation in rodents using the object pattern separation task. Nat Protoc 2018; 13:1763-1792. [DOI: 10.1038/s41596-018-0013-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Abstract
Memories for events are thought to be represented in sparse, distributed neuronal ensembles (or engrams). In this article, we review how neurons are chosen to become part of a particular engram, via a process of neuronal allocation. Experiments in rodents indicate that eligible neurons compete for allocation to a given engram, with more excitable neurons winning this competition. Moreover, fluctuations in neuronal excitability determine how engrams interact, promoting either memory integration (via coallocation to overlapping engrams) or separation (via disallocation to nonoverlapping engrams). In parallel with rodent studies, recent findings in humans verify the importance of this memory integration process for linking memories that occur close in time or share related content. A deeper understanding of allocation promises to provide insights into the logic underlying how knowledge is normally organized in the brain and the disorders in which this process has gone awry.
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Affiliation(s)
- Sheena A Josselyn
- Department of Psychology, University of Toronto, Ontario M5S 3G3, Canada; ,
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Physiology, University of Toronto, Ontario M5S 1A8, Canada
- Institute of Medical Sciences, University of Toronto, Ontario M5S 1A8, Canada
- Brain, Mind & Consciousness Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1M1, Canada
| | - Paul W Frankland
- Department of Psychology, University of Toronto, Ontario M5S 3G3, Canada; ,
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Physiology, University of Toronto, Ontario M5S 1A8, Canada
- Institute of Medical Sciences, University of Toronto, Ontario M5S 1A8, Canada
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1M1, Canada
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Keresztes A, Ngo CT, Lindenberger U, Werkle-Bergner M, Newcombe NS. Hippocampal Maturation Drives Memory from Generalization to Specificity. Trends Cogn Sci 2018; 22:676-686. [PMID: 29934029 DOI: 10.1016/j.tics.2018.05.004] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/27/2018] [Accepted: 05/17/2018] [Indexed: 01/15/2023]
Abstract
During early ontogeny, the rapid and cumulative acquisition of world knowledge contrasts with slower improvements in the ability to lay down detailed and long-lasting episodic memories. This emphasis on generalization at the expense of specificity persists well into middle childhood and possibly into adolescence. During this period, recognizing regularities, forming stable representations of recurring episodes, predicting the structure of future events, and building up semantic knowledge may be prioritized over remembering specific episodes. We highlight recent behavioral and neuroimaging evidence suggesting that maturational differences among subfields within the hippocampus contribute to the developmental lead-lag relation between generalization and specificity, and lay out future research directions.
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Affiliation(s)
- Attila Keresztes
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.
| | - Chi T Ngo
- Department of Psychology, Temple University, Philadelphia, PA, USA
| | - Ulman Lindenberger
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany; Max Planck-University College London (UCL) Centre for Computational Psychiatry and Ageing Research, London, England, and Berlin, Germany
| | - Markus Werkle-Bergner
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany
| | - Nora S Newcombe
- Department of Psychology, Temple University, Philadelphia, PA, USA
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Poli D, Wheeler BC, DeMarse TB, Brewer GJ. Pattern separation and completion of distinct axonal inputs transmitted via micro-tunnels between co-cultured hippocampal dentate, CA3, CA1 and entorhinal cortex networks. J Neural Eng 2018; 15:046009. [PMID: 29623900 DOI: 10.1088/1741-2552/aabc20] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE Functions ascribed to the hippocampal sub-regions for encoding episodic memories include the separation of activity patterns propagated from the entorhinal cortex (EC) into the dentate gyrus (DG) and pattern completion in CA3 region. Since a direct assessment of these functions is lacking at the level of specific axonal inputs, our goal is to directly measure the separation and completion of distinct axonal inputs in engineered pairs of hippocampal sub-regional circuits. APPROACH We co-cultured EC-DG, DG-CA3, CA3-CA1 or CA1-EC neurons in a two-chamber PDMS device over a micro-electrode array (MEA60), inter-connected via distinct axons that grow through the micro-tunnels between the compartments. Taking advantage of the axonal accessibility, we quantified pattern separation and completion of the evoked activity transmitted through the tunnels from source into target well. Since pattern separation can be inferred when inputs are more correlated than outputs, we first compared the correlations among axonal inputs with those of target somata outputs. We then compared, in an analog approach, the distributions of correlation distances between rate patterns of the axonal inputs inside the tunnels with those of the somata outputs evoked in the target well. Finally, in a digital approach, we measured the spatial population distances between binary patterns of the same axonal inputs and somata outputs. MAIN RESULTS We found the strongest separation of the propagated axonal inputs when EC was axonally connected to DG, with a decline in separation to CA3 and to CA1 for both rate and digital approaches. Furthermore, the digital approach showed stronger pattern completion in CA3, then CA1 and EC. SIGNIFICANCE To the best of our knowledge, these are the first direct measures of pattern separation and completion for axonal transmission to the somata target outputs at the rate and digital population levels in each of four stages of the EC-DG-CA3-CA1 circuit.
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Affiliation(s)
- Daniele Poli
- Department of Biomedical Engineering, University of California, Irvine, CA, United States of America. Research Center 'Enrico Piaggio', University of Pisa, Pisa, Italy
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Kraguljac NV, Carle M, Frölich MA, Tran S, Yassa MA, White DM, Reddy A, Lahti AC. RETRACTED: Mnemonic Discrimination Deficits in First-Episode Psychosis and a Ketamine Model Suggests Dentate Gyrus Pathology Linked to N-Methyl-D-Aspartate Receptor Hypofunction. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2018; 3:231-238. [PMID: 29486864 PMCID: PMC5836317 DOI: 10.1016/j.bpsc.2017.02.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 02/19/2017] [Indexed: 01/21/2023]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). Retraction notice to: “Mnemonic Discrimination Deficits in First-Episode Psychosis and a Ketamine Model Suggests Dentate Gyrus Pathology Linked to N-Methyl-D-Aspartate Receptor Hypofunction” by Nina Vanessa Kraguljac, Matthew Carle, Michael A. Frölich, Steve Tran, Michael A. Yassa, David Matthew White, Abhishek Reddy, and Adrienne Carol Lahti (Biol Psychiatry Cogn Neurosci Neuroimaging 2018; 3:231-238); https://doi.org/10.1016/j.bpsc.2017.02.005. This article has been retracted at the request of Cameron S. Carter, M.D., Editor of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, with agreement from all authors. The authors discovered an error in the calculation of the response bias–corrected pattern recognition score in this article, which has significantly changed the results for experiment 1. Specifically, the authors discovered that the response bias corrected pattern recognition score was erroneously computed as P(‘old’|target) minus P(‘old’|lure) rather than P(‘old’|target) minus P(‘old’|foil). After re-running statistical analyses with the correct values, the authors found a significant difference in the response bias–corrected pattern recognition score in healthy volunteers (HV) compared with first-episode psychosis (FEP) patients (HV: 84.13 ± 10.96; FEP: 63.70 ± 21.83; t = 4.01; p < .01) in experiment 1. This finding is not consistent with the original report, where the authors reported no group differences in bias-corrected pattern recognition scores (originally reported values: t = 0.93, p = .36). The authors again found no significant correlations between pattern completion scores and BPRS total, positive, or negative symptom scores or RBANS scores, consistent with the original report. In experiment 2, bias-corrected pattern recognition scores did not differ between the saline and ketamine conditions (saline: 78.29 ± 28.04; ketamine: 73.59 ± 18.94; t = 0.81; p = 0.43), which is consistent with the original report (originally reported values: t = −0.69, p = .50). Contrary to the original report, task performance during the saline and ketamine infusions was no longer correlated at trend level for pattern recognition. Repeat analyses showed no correlations between pattern recognition scores during the ketamine challenge and BPRS total, positive, and negative symptom scores, or ketamine plasma levels at either time point, consistent with the original report. The authors have verified that bias-corrected pattern separation scores were calculated correctly for both experiments in the initial report. This error affects the abstract, the results, Figure 1, and discussion of the manuscript. The authors voluntarily informed the Journal of this honest error upon its discovery. Because of the extent and nature of the changes to the paper, the editors and authors concluded that, to ensure maximum clarity and transparency, the only course of action was to retract this version of the paper. The authors are revising the paper, which the Journal will re-review and consider further for publication.
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Affiliation(s)
- Nina Vanessa Kraguljac
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Matthew Carle
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michael A Frölich
- Department of Anesthesiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Steve Tran
- Department of Anesthesiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michael A Yassa
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, California
| | - David Matthew White
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Abhishek Reddy
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Adrienne Carol Lahti
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama.
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Hui CW, St-Pierre A, El Hajj H, Remy Y, Hébert SS, Luheshi GN, Srivastava LK, Tremblay MÈ. Prenatal Immune Challenge in Mice Leads to Partly Sex-Dependent Behavioral, Microglial, and Molecular Abnormalities Associated with Schizophrenia. Front Mol Neurosci 2018; 11:13. [PMID: 29472840 PMCID: PMC5809492 DOI: 10.3389/fnmol.2018.00013] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/09/2018] [Indexed: 01/25/2023] Open
Abstract
Epidemiological studies revealed that environmental factors comprising prenatal infection are strongly linked to risk for later development of neuropsychiatric disorders such as schizophrenia. Considering strong sex differences in schizophrenia and its increased prevalence in males, we designed a methodological approach to investigate possible sex differences in pathophysiological mechanisms. Prenatal immune challenge was modeled by systemic administration of the viral mimic polyinosinic-polycytidylic acid (Poly I:C) to C57BL/6 mice at embryonic day 9.5. The consequences on behavior, gene expression, and microglia—brain immune cells that are critical for normal development—were characterized in male vs. female offspring at adulthood. The cerebral cortex, hippocampus, and cerebellum, regions where structural and functional alterations were mainly described in schizophrenia patients, were selected for cellular and molecular analyses. Confocal and electron microscopy revealed most pronounced differences in microglial distribution, arborization, cellular stress, and synaptic interactions in the hippocampus of male vs. female offspring exposed to Poly I:C. Sex differences in microglia were also measured under both steady-state and Poly I:C conditions. These microglial alterations were accompanied by behavioral impairment, affecting for instance sensorimotor gating, in males. Consistent with these results, increased expression of genes related to inflammation was measured in cerebral cortex and hippocampus of males challenged with Poly I:C. Overall, these findings suggest that schizophrenia's higher incidence in males might be associated, among other mechanisms, with an increased microglial reactivity to prenatal immune challenges, hence determining disease outcomes into adulthood.
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Affiliation(s)
- Chin W Hui
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Abygaël St-Pierre
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Hassan El Hajj
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Yvan Remy
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Sébastien S Hébert
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada.,Département de Psychiatrie et Neurosciences, Université Laval, Québec, QC, Canada
| | - Giamal N Luheshi
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montréal, QC, Canada
| | - Lalit K Srivastava
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montréal, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
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46
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Aldi GA, Lange I, Gigli C, Goossens L, Schruers KR, Cosci F. Validation of the Mnemonic Similarity Task - Context Version. ACTA ACUST UNITED AC 2018; 40:432-440. [PMID: 29412339 PMCID: PMC6899373 DOI: 10.1590/1516-4446-2017-2379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/25/2017] [Indexed: 12/25/2022]
Abstract
Objective: Pattern separation (PS) is the ability to represent similar experiences as separate, non-overlapping representations. It is usually assessed via the Mnemonic Similarity Task – Object Version (MST-O) which, however, assesses PS performance without taking behavioral context discrimination into account, since it is based on pictures of everyday simple objects on a white background. We here present a validation study for a new task, the Mnemonic Similarity Task – Context Version (MST-C), which is designed to measure PS while taking behavioral context discrimination into account by using real-life context photographs. Methods: Fifty healthy subjects underwent the two MST tasks to assess convergent evidence. Instruments assessing memory and attention were also administered to study discriminant evidence. The test-retest reliability of MST-C was analyzed. Results: Weak evidence supports convergent validity between the MST-C task and the MST-O as measures of PS (rs = 0.464; p < 0.01); PS performance assessed via the MST-C did not correlate with memory or attention; a moderate test-retest reliability was found (rs = 0.595; p < 0.01). Conclusion: The MST-C seems useful for assessing PS performance conceptualized as the ability to discriminate complex and realistic spatial contexts. Future studies are welcome to evaluate the validity of the MST-C task as a measure of PS in clinical populations.
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Affiliation(s)
- Giulia A Aldi
- Dipartimento di Scienze della Salute, Università di Firenze, Firenze, Italy
| | - Iris Lange
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, The Netherlands
| | - Cristiana Gigli
- Dipartimento di Scienze della Salute, Università di Firenze, Firenze, Italy
| | - Lies Goossens
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, The Netherlands
| | - Koen R Schruers
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, The Netherlands
| | - Fiammetta Cosci
- Dipartimento di Scienze della Salute, Università di Firenze, Firenze, Italy
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47
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Leal SL, Yassa MA. Integrating new findings and examining clinical applications of pattern separation. Nat Neurosci 2018; 21:163-173. [PMID: 29371654 PMCID: PMC5898810 DOI: 10.1038/s41593-017-0065-1] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 10/28/2017] [Indexed: 11/09/2022]
Abstract
Pattern separation, the ability to independently represent and store similar experiences, is a crucial facet of episodic memory. Growing evidence suggests that the hippocampus possesses unique circuitry that is computationally capable of resolving mnemonic interference by using pattern separation. In this Review, we discuss recent advances in the understanding of this process and evaluate the caveats and limitations of linking across animal and human studies. We summarize clinical and translational studies using methods that are sensitive to pattern separation impairments, an approach that stems from the fact that the hippocampus is a major site of disruption in many brain disorders. We critically evaluate the assumptions that guide fundamental and translational studies in this area. Finally, we suggest guidelines for future research and offer ways to overcome potential interpretational challenges to increase the utility of pattern separation as a construct that can further understanding of both memory processes and brain disease.
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Affiliation(s)
- Stephanie L Leal
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Michael A Yassa
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, USA.
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48
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Abstract
Maintaining similar memories in a distinct and nonoverlapping manner, known as pattern separation, is an important mnemonic process. The medial temporal lobe, especially the hippocampus, has been implicated in this crucial memory function. The present study thus examines whether it is possible to modulate pattern separation using bilateral transcranial direct current stimulation (tDCS) over the temporal lobes. Specifically, in this study, pattern separation was assessed using the Mnemonic Similarity Task following 15-min offline bilateral temporal lobe tDCS (left cathode and right anode or left anode and right cathode) or sham stimulation. In the Mnemonic Similarity Task, participants studied a series of sequentially presented visual objects. In the subsequent recognition memory test, participants viewed a series of sequentially presented objects that could be old images from study, novel foils, or lures that were visually similar to the studied images. Participants reported whether these images were exactly the same as, similar to, or different from the studied images. Following both active tDCS conditions, participants were less likely to identify lures as 'similar' compared with the sham condition, indicating a reduction in pattern separation resulting from temporal lobe tDCS. In contrast, no significant difference in overall accuracy was found for participants' discrimination of old and new images. Together, these results suggest that temporal lobe tDCS can selectively modulate the pattern separation function without changing participants' baseline recognition memory performance.
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49
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Gandy K, Kim S, Sharp C, Dindo L, Maletic-Savatic M, Calarge C. Pattern Separation: A Potential Marker of Impaired Hippocampal Adult Neurogenesis in Major Depressive Disorder. Front Neurosci 2017; 11:571. [PMID: 29123464 PMCID: PMC5662616 DOI: 10.3389/fnins.2017.00571] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/29/2017] [Indexed: 12/26/2022] Open
Abstract
Adult neurogenesis involves the generation of new neurons, particularly in the dentate gyrus of the hippocampus. Decreased hippocampal neurogenesis has been implicated in both animal models of depression and in patients with major depressive disorder (MDD), despite some inconsistency in the literature. Here, we build upon current models to generate a new testable hypothesis, linking impaired neurogenesis to downstream psychological outcomes commonly observed in MDD. We contend that disruption in adult neurogenesis impairs pattern separation, a hippocampus-dependent function requiring the careful discrimination and storage of highly similar, but not identical, sensory inputs. This, in turn, can affect downstream processing and response selection, of relevance to emotional wellbeing. Specifically, disrupted pattern separation leads to misperceived stimuli (i.e., stimulus confusion), triggering the selection and deployment of established responses inappropriate for the actual stimuli. We speculate that this may be akin to activation of automatic thoughts, described in the Cognitive Behavior Theory of MDD. Similarly, this impaired ability to discriminate information at a fundamental sensory processing level (e.g., impaired pattern separation) could underlie impaired psychological flexibility, a core component of Acceptance and Commitment Therapy of MDD. We propose that research is needed to test this model by examining the relationship between cognitive functioning (e.g., pattern separation ability), psychological processes (e.g., perseveration and psychological inflexibility), and neurogenesis, taking advantage of emerging magnetic resonance spectroscopy-based imaging that measures neurogenesis in-vivo.
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Affiliation(s)
- Kellen Gandy
- Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, United States
| | - Sohye Kim
- Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, United States
- Department of Obstetrics and Gynecology, Baylor College of Medicine and Center for Reproductive Psychiatry, Pavilion for Women, Texas Children's Hospital, Houston, TX, United States
- Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, TX, United States
| | - Carla Sharp
- Department of Psychology, University of Houston, Houston, TX, United States
| | - Lilian Dindo
- Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, United States
| | - Mirjana Maletic-Savatic
- Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, TX, United States
- Dan and Jan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States
| | - Chadi Calarge
- Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, United States
- Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, TX, United States
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50
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Cès A, Burg T, Herbeaux K, Héraud C, Bott JB, Mensah-Nyagan AG, Mathis C. Age-related vulnerability of pattern separation in C57BL/6J mice. Neurobiol Aging 2017; 62:120-129. [PMID: 29149630 DOI: 10.1016/j.neurobiolaging.2017.10.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 09/25/2017] [Accepted: 10/16/2017] [Indexed: 01/22/2023]
Abstract
Aging is associated with impaired performance in behavioral pattern separation (PS) tasks based on similarities in object features and in object location. These deficits have been attributed to functional alterations in the dentate gyrus (DG)-CA3 region. Animal studies suggested a role of adult-born DG neurons in PS performance. The present study investigated the effect of aging in C57BL/6J mice performing PS tasks based on either object features or object location. At the age of 18 months or more, performance was severely impaired in both tasks. Spatial PS performance declined gradually over adult lifespan from 3 to 21 months. Subchronic treatment with the cognitive enhancer D-serine fully rescued spatial PS performance in 18-month-old mice and induced a modest increase in the number of 4-week-old adult-born cells in the DG. Performance of mice in these PS tasks shows an age dependence, which appears to translate well to that found in humans. This model should help in deciphering physiological changes underlying PS deficits and in identifying future therapeutic targets.
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Affiliation(s)
- Aurélia Cès
- Université de Strasbourg, CNRS UMR 7364, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), 12 Rue Goethe, Strasbourg, France
| | - Thibaut Burg
- Université de Strasbourg, CNRS UMR 7364, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), 12 Rue Goethe, Strasbourg, France
| | - Karine Herbeaux
- Université de Strasbourg, CNRS UMR 7364, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), 12 Rue Goethe, Strasbourg, France
| | - Céline Héraud
- Université de Strasbourg, CNRS UMR 7364, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), 12 Rue Goethe, Strasbourg, France
| | - Jean-Bastien Bott
- Université de Strasbourg, CNRS UMR 7364, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), 12 Rue Goethe, Strasbourg, France
| | - Ayikoe Guy Mensah-Nyagan
- Université de Strasbourg, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, Bâtiment 3 de la Faculté de Médecine, 11 Rue Humann, Strasbourg, France
| | - Chantal Mathis
- Université de Strasbourg, CNRS UMR 7364, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), 12 Rue Goethe, Strasbourg, France.
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