Hippocampus最新文献

{"title":"Phylogeny of Cortical-Hippocampal Projections Reveals Selective Elimination of Input From Sensory Regions.","authors":"Daniel Reznik, Piotr Majka, Marcello G P Rosa, Menno P Witter, Christian F Doeller","doi":"10.1002/hipo.70119","DOIUrl":"10.1002/hipo.70119","url":null,"abstract":"<p><p>The study of cross-species differences in the organization of the cerebral cortex received significant attention during the past century. However, the evolutionary principles governing changes in brain connectivity and their impact on cognition remain poorly understood. In the current study, we analyzed differences in anatomical input from the cerebral cortex to the hippocampal region across six species spanning more than 100 million years of mammalian evolution-the tenrec, rat, cat, marmoset, macaque and human. Our results demonstrate that, unlike direct transmodal cortical input, direct unimodal cortical input to the hippocampal region was selectively eliminated with the increase in brain size. Additionally, input from primary sensory regions was eliminated prior to input from non-primary sensory regions. Our findings suggest that hippocampus-related processes in different species operate on fundamentally different types of information, potentially underpinning cross-species differences in hippocampus-dependent cognition. Furthermore, our findings outline the evolutionary trajectory of the anatomical circuitry associating the human hippocampal region with the neocortex.</p>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":"e70119"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13542335/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148887287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diurnal Regulation of Hippocampal Synaptic Plasticity in Aged Rats and the Role of the Circadian Clock Gene Per1","authors":"Liam T. Ralph,&nbsp;Shinwon Kang,&nbsp;Lauren A. Joe,&nbsp;Patrick Tidball,&nbsp;Ahmad R. Israwi,&nbsp;Meng Tian,&nbsp;Ashish Kadia,&nbsp;Lijia Zhang,&nbsp;Fuzi Jin,&nbsp;Rachael Ingram,&nbsp;Zuner A. Bortolotto,&nbsp;Stafford L. Lightman,&nbsp;Becky L. Conway-Campbell,&nbsp;Joanne E. Nash,&nbsp;Janice Robertson,&nbsp;Clarrisa A. Bradley,&nbsp;Marina Gertsenstein,&nbsp;Lauryl M. J. Nutter,&nbsp;John Georgiou,&nbsp;Graham L. Collingridge","doi":"10.1002/hipo.70118","DOIUrl":"https://doi.org/10.1002/hipo.70118","url":null,"abstract":"<p>Period circadian regulator 1 (PER1) regulates circadian gene expression and is critical for spatial memory. However, its role in regulating synaptic plasticity between diurnal phases remains largely unknown. Here, we examined long-term potentiation (LTP) and long-term synaptic depression (LTD) in hippocampal slices prepared from aged male <i>Per1</i> knockout (<i>Per1</i> KO) rats and their wildtype (WT) littermates during the light/inactive and dark/active phases. In WT rats, theta-burst stimulation (TBS) consistently induced stable LTP that was greater during the dark relative to the light phase. In contrast, in <i>Per1</i> KO rats, TBS resulted in synaptic potentiation that decayed to baseline levels within ~90 min in both phases. Notably, WT rats readily expressed LTD following 1 Hz low-frequency stimulation (LFS) during the dark phase but not the light phase. By comparison, in <i>Per1</i> KO rats, LTD was inducible by LFS during both the dark and light phases. LTD in both WT and <i>Per1</i> KO rats was dependent on the activation of <i>N</i>-methyl-<span>d</span>-aspartate receptors. Basal synaptic transmission was reduced and GluA1 S845 phosphorylation was increased during the dark phase in both WT and <i>Per1</i> KO rats. Together, our findings identify PER1 as a key regulator of synaptic plasticity between diurnal phases in aged rats.</p>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hipo.70118","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148849209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-Unit Activity in the Human Medial Temporal Lobe Reflects Reduced Error Monitoring During Mind Wandering","authors":"Thomas P. Reber,&nbsp;Leila Chaieb,&nbsp;Marlene Derner,&nbsp;Valeri Borger,&nbsp;Rainer Surges,&nbsp;Florian Mormann,&nbsp;Juergen Fell","doi":"10.1002/hipo.70125","DOIUrl":"10.1002/hipo.70125","url":null,"abstract":"<p>Mind wandering (MW) has been frequently reported to impair task performance. In this study, we investigated the hypothesis that it also affects error monitoring and adjustment. Several recent studies suggest that the hippocampus and adjacent regions significantly contribute to error monitoring. Therefore, we analyzed single-unit recordings from the medial temporal lobe (MTL) in presurgical epilepsy patients performing an attention task, which included interspersed experience sampling probes. Behavioral performance data revealed reduced error adjustment during periods of MW compared to task-focused attention. Analysis of single-unit recordings showed population responses related to performance errors within the hippocampus and adjacent regions, supporting the idea that MTL regions contribute to error monitoring. Importantly, this error-related population activity was significantly reduced during periods of MW compared to task focus. Together, our findings clearly support the hypothesis that MW impairs both error monitoring and adjustment.</p>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hipo.70125","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148827759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association Between Anterior Hippocampal Gyrification and Episodic Memory Performance in Neurotypical Young Adults","authors":"Nima Talaei,&nbsp;Jordan DeKraker,&nbsp;Bradley G. Karat,&nbsp;Ali R. Khan,&nbsp;Stefan Köhler","doi":"10.1002/hipo.70124","DOIUrl":"10.1002/hipo.70124","url":null,"abstract":"<p>The hippocampus is critical for episodic memory. The relationship between its structural variability and individual differences in episodic memory performance among neurotypical young adults, however, remains unclear. Previous studies have not consistently found associations between hippocampal volume and episodic memory or other aspects of hippocampally dependent performance in this population. Here, we moved beyond volumetric approaches and tested whether more fine-grained morphometric features, particularly gyrification, are related to behavioral performance. To obtain these measures, we used HippUnfold, a deep learning-based segmentation tool that models the hippocampus as a folded cortical ribbon and uniquely quantifies local variability in folding patterns, including in the hippocampal head. We focused on an open-access dataset with high-resolution MRI scans and multiple behavioral measures on hippocampal-dependent tasks, including episodic and semantic components of the Autobiographical Interview. To improve segmentation quality for the high-resolution images in this dataset, we trained an nnU-Net segmentation model for HippUnfold that was optimized for high-resolution T2w images. Volumetric and surface-based measures were computed for 186 participants (97 female). We found no reliable associations between hippocampal volumetric measures, including subfield volumes, and behavioral performance. In contrast, surface-based analysis of hippocampal gyrification revealed significant bilateral clusters in the anterior hippocampus, both of which were associated with measures of episodic but not semantic autobiographical memory. The right hemisphere cluster was located in the subiculum and CA1, whereas the left hemisphere cluster was primarily situated in the subiculum. These findings demonstrate the utility of surface-based hippocampal morphometry for linking hippocampal structure to behavioral performance. They suggest that even in neurotypical young adults individual differences in episodic memory are tied to structural hippocampal variation.</p>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13501942/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148808500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissociation of Memory for Order and Memory for Items by Concurrent Cognitive Load in Rhesus Monkeys (Macaca mulatta)","authors":"Pankhuri Singhal,&nbsp;Victoria L. Templer,&nbsp;Robert R. Hampton","doi":"10.1002/hipo.70123","DOIUrl":"https://doi.org/10.1002/hipo.70123","url":null,"abstract":"<div>\u0000 \u0000 <p>Memory of the order in which events occurred addresses the “when” component of episodic-like memory in animals. Seminal work demonstrated that normal rats remember the order in which they encountered odors, and hippocampal lesions selectively impaired this memory for order while leaving recognition performance intact. This work inspired us to develop an image-order paradigm to model episodic memory in monkeys. Monkeys saw five images in sequence and at test reported which of two images appeared first. Unlike the case with rats, hippocampal lesions did not impair memory for order, raising questions about which memory systems monkeys used in this task. Because the memory intervals were short in the image-order task, monkeys may have used nonhippocampal-dependent working memory instead of long-term memory. To test this possibility, we introduced a concurrent cognitive load between the study and test phases of the image-order task. We hypothesized that if monkeys were using working memory to remember the order of the images, concurrent cognitive load would impair performance. We also tested recognition performance as a control, because familiarity-based recognition is relatively resistant to concurrent cognitive load. Memory for order was much more attenuated by concurrent cognitive load than recognition. These results indicate that monkeys used working memory to solve this image-order task, making it a poor model of long-term episodic memory. The findings also provide clear evidence for a dissociation between working memory-dependent order memory and familiarity-based recognition memory.</p>\u0000 </div>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148785030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential Functional Connectivity Between Hippocampus and Prefrontal Cortex Is Associated With Heterogeneity in Open Field Exploration and Is Disrupted Following Maternal Immune Activation","authors":"Robert G. K. Munn,&nbsp;Desiree D. Dickerson,&nbsp;Amy R. Wolff,&nbsp;David K. Bilkey","doi":"10.1002/hipo.70122","DOIUrl":"https://doi.org/10.1002/hipo.70122","url":null,"abstract":"<p>A common paradigm in behavioral neuroscience involves recording neural activity from freely moving rodents as they forage in an open field. This procedure is often used in studies investigating spatial navigation, where recording is conducted in regions such as the hippocampus and entorhinal cortex. It is usually assumed that there is no systematic variation in behavior in this paradigm, thereby allowing spatial representations to be examined without the confounding effects of behavior change. Here we show that the behavior of rats in this paradigm can be algorithmically divided into at least two distinct modes, and that the transitions between these modes are marked by distinct differences in theta and gamma band power in the hippocampus, as well as transition-associated communication between hippocampus and prefrontal cortex, with information strongly flowing from hippocampus to prefrontal cortex during the transition period. Moreover, we show that following a maternal immune activation intervention, intraregional changes in power are preserved, but communication between hippocampus and prefrontal cortex is impaired. These findings demonstrate that animals in the open field perform distinct behaviors that are accompanied by marked changes in brain activity and regional communication.</p>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hipo.70122","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Role of Hippocampal Interneuron Migration in Neurodevelopmental Disorders: A Systematic Review","authors":"M. A. C. Till,&nbsp;H. M. O. Reid,&nbsp;I. Murphy,&nbsp;B. R. Christie","doi":"10.1002/hipo.70121","DOIUrl":"https://doi.org/10.1002/hipo.70121","url":null,"abstract":"<p>Hippocampal abnormalities are frequently associated with neurodevelopmental disorders as interneurons are crucial in establishing the network connectivity of neurons. This systematic review analyzed primary literature with a focus on aberrant hippocampal interneuron migration as an etiology for neurodevelopmental disorders, summarizing the current field and identifying gaps that require further understanding. We adhered to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines to perform a comprehensive review of the existing research on GABAergic, parvalbumin, somatostatin, cholecystokinin, neuropeptide Y, calbindin, and calretinin interneuron migration in the hippocampus. Three blocks of search terms were used to extract 1459 papers from the PubMed, PsycINFO, and Web of Science databases. Following screening, we identified 29 articles which met the inclusion/exclusion criteria for the study. There is evidence that interneurons are affected in many neurodevelopmental conditions, with distinct regional and subtype-specific differences. This systematic review has determined that there is a clear association between deficits in interneuron migration to the hippocampus and the presentation of neurodevelopmental disorders. The review highlights a significant lack of sex differences considered in the field, as well as a paucity of data for many specific neurodevelopmental conditions.</p>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hipo.70121","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cancer Treatment and Memory in Breast Cancer Survivors: Differential Effects on Detailed Episodic and Gist-Like Memory Recall Over Time","authors":"Meenakshie Bradley-Garcia,&nbsp;Hamed Neveu Karimpour,&nbsp;Defne Oksit,&nbsp;Mitchell Lilley,&nbsp;Chloé Cateaux,&nbsp;Annick F. Tanguay,&nbsp;Melanie J. Sekeres","doi":"10.1002/hipo.70120","DOIUrl":"https://doi.org/10.1002/hipo.70120","url":null,"abstract":"<p>Breast cancer survivors (BCS) frequently experience chemotherapy-related cognitive impairment, including episodic memory deficits. This study examined the long-term impact of cancer treatment on memory for naturalistic events, using film clips to assess recall of central (gist-like elements; reflects the story narrative) and peripheral (episodic elements; sensory or contextual details related to the event) details. While memory for both types of details typically declines over time, peripheral details are especially vulnerable to decline, and are sensitive to impairment in individuals with medial temporal lobe disruption. Participants (BCS, <i>n</i> = 42; noncancer controls, NC, <i>n</i> = 41) viewed 40 short film clips (encoding). Memory for the clips' content was tested at two timepoints: immediately following encoding (20 clips; immediate retrieval) and after a 7-day delay (20 clips; delayed retrieval). BCS recalled significantly fewer peripheral details than NC, whereas recall of central (gist-like) information did not differ between groups. No group differences were observed across individual sub-categories of peripheral details, temporal sequencing, or the rate of forgetting over the 7-day delay. Subjective memory ratings mirrored objective performance, with BCS reporting lower memory vividness than NC, while reporting comparable memory for story content. These findings suggest that chemotherapy may reduce the overall richness of episodic event representations while preserving central, schematic aspects of memory and the temporal organization of events. Naturalistic memory paradigms that assess the qualitative features of event memory may provide a sensitive approach for detecting subtle treatment-related cognitive changes in cancer survivors.</p>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hipo.70120","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intrinsic Excitability of Rat Hippocampal Granule Cells Increases Along the Dorsal-to-Ventral Axis","authors":"Sanjna Kumari,&nbsp;Rishikesh Narayanan","doi":"10.1002/hipo.70117","DOIUrl":"10.1002/hipo.70117","url":null,"abstract":"<div>\u0000 \u0000 <p>The dentate gyrus (DG) of the hippocampus exhibits striking anatomical and functional heterogeneity along its dorsoventral axis, yet the intrinsic electrophysiological diversity of its principal excitatory neurons, the granule cells, across the dorsoventral axis remains unexplored. Here, we systematically examined the electrophysiological properties of DG granule cells across the dorsal, intermediate, and ventral regions of the rat hippocampus. We found a progressive increase in input resistance, impedance amplitude, and firing rate of granule cells, accompanied by a gradual slowdown in repolarization kinetics of their action potentials along the dorsal-to-ventral axis. Our analyses demonstrated that granule cells acted as class I integrators that lacked strong resonance properties across the dorsoventral axis. We performed pairwise correlation and dimensionality reduction analyses to reveal weak dependencies across physiological measurements and the absence of distinct clusters for dorsal, intermediate, or ventral granule cells. Importantly, blade-specific analyses of granule cell physiology revealed that all measurements manifested pronounced heterogeneities even within a given dorsoventral section and a specific blade. Strikingly, ventral granule cells in the infrapyramidal blade manifested higher firing rates compared to their counterparts in the suprapyramidal blade. These blade-specific differences were limited to the ventral granule cells, with negligible distinctions between granule cells in the two blades of either dorsal or intermediate hippocampus. Together, our findings unveil a progressive increase in excitability of DG granule cells along the dorsal-to-ventral axis and a blade-specific granularity of firing properties, adding new dimensions to the several known anatomical, molecular, and behavioral differences across the hippocampal dorsoventral axis.</p>\u0000 </div>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148701089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Quest for the Associative Device for Hebbian-Like LTP—The Accidental Participant","authors":"Bengt Gustafsson","doi":"10.1002/hipo.70116","DOIUrl":"10.1002/hipo.70116","url":null,"abstract":"<p>In 1985 Holger Wigström (now deceased) and I published a proposed scenario for the induction of hippocampal Hebbian-like LTP to explain its input specificity and cooperativity. In this scenario LTP is induced by calcium influx through voltage-dependent NMDA receptor channels co-localized with the glutamate receptor channels (non-NMDA) mediating the expression of LTP. This co-localization, we argued, explained the input specificity, and the voltage dependence of these NMDA receptor channels explained the cooperativity. It will be described how this scenario emerged from our finding of a greatly facilitated LTP induction following blockade of postsynaptic inhibition, from our observation of a dendritic, possibly regenerative, event correlated with successful LTP induction, and to our recognition that these events were the result of NMDA receptor activation. Our observation of a likely synaptic co-localization of these receptor channels with the non-NMDA receptor channels, with the former contributing to an EPSP component with a slower onset and much longer duration, will be described. Finally, I will describe how our scenario became validated by our experiments pairing such single EPSPs with depolarization induced by injected current pulses, temporally associated with the NMDA component. This essay will conclude with some take-home messages regarding the Hebbian-like LTP as learned from these experiments: this form of synaptic learning most likely only occurs during disinhibition, its longevity strongly depends on the induction strength from a few minutes and upwards, with a strong induction event it can operate as a one-shot potentiation, and its time window for association may remain several 100 ms. Lastly, Hebbian-like LTP likely evolved to associate input events rather than an input event and somatic spike activity.</p>","PeriodicalId":13171,"journal":{"name":"Hippocampus","volume":"36 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13439494/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148673628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}