Article
Neurosciences
Sachin S. Deshmukh
Summary: The study shows that the inputs from different regions in the proximal and distal CA1 areas cause differential representation responses. While pCA1 representation splits when faced with conflicting inputs, dCA1 is more influenced by global cues. Overall spatial selectivity is not significantly different, possibly due to the richer sensory information available in the behavioral environment.
JOURNAL OF NEUROSCIENCE
(2021)
Review
Behavioral Sciences
Maxime Levesque, Giuseppe Biagini, Marco de Curtis, Vadym Gnatkovsky, Julika Pitsch, Siyan Wang, Massimo Avoli
Summary: Research on the mechanisms of focal epileptic discharges in mesial temporal lobe epilepsy (MTLE) often utilizes rodent models induced by pilocarpine, revealing specific neuronal events during latent and chronic states, as well as the effects of optogenetic activation on spontaneous seizures.
NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS
(2021)
Article
Multidisciplinary Sciences
Ingvild Ulsaker-Janke, Torgeir Waaga, Tanja Waaga, Edvard I. Moser, May - Britt Moser
Summary: This study found that rats can develop grid-like neuron firing patterns in a specific environment, even without stable reference boundaries to guide them. After a few trials of training, these patterns become more clear. While some experience with external spatial boundaries is required for the expression of grid patterns in a new environment, this restricted spatial experience can be overcome with short-term training.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Cell Biology
Bingxuan Han, Shuang Cui, Feng-Yu Liu, You Wan, Yan Shi, Ming Yi
Summary: The study found that inhibiting the activity of pyramidal neurons in the ventral hippocampal CA1 area increases water intake in rats. The results suggest that the hippocampus plays an important role in regulating drinking behavior, but the specific mechanisms need further investigation.
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
(2021)
Article
Neurosciences
Farnaz Sharif, Behnam Tayebi, Gyorgy Buzsaki, Sebastien Royer, Antonio Fernandez-Ruiz
Summary: Hippocampal neurons exhibit different spatial coding characteristics in different environments, with superficial place cells more active in cue-poor environments and deep place cells more active in cue-rich environments. These differences are driven by intra-hippocampal and entorhinal inputs, supported by the interaction between excitatory gamma inputs and local inhibition.
Article
Neurosciences
Pierre Lecouflet, Candice M. Roux, Brigitte Potier, Marianne Leger, Elie Brunet, Jean-Marie Billard, Pascale Schumann-Bard, Thomas Freret
Summary: Activation of the 5-HT4R has been shown to impact LTP within the hippocampal CA1 area through modulation of GABAergic neurotransmission. The study also revealed the involvement of GABA(B) receptor in this regulatory process.
Article
Clinical Neurology
Shinnosuke Shiono, Huayu Sun, Tamal Batabyal, Aleksandra Labuz, John Williamson, Jaideep Kapur, Suchitra Joshi
Summary: Activation of PRs in the EC and hippocampus increases neuronal excitability and worsens seizures. These receptors may play a role in catamenial epilepsy.
Article
Neurosciences
Tsvetomira Atanasova, Tiina Savonlehto, Tiina-Kaisa Kukko-Lukjanov, Zoia Kharybina, Wei-Chih Chang, Sari E. Lauri, Tomi Taira
Summary: Kainate receptors play an important role in the development and pathological synchronization of the hippocampal neural network. GluK1 KARs regulate functional connectivity between excitatory neurons, possibly through morphological changes in the glutamatergic circuit that affect the synchronization of neuronal populations.
Article
Neurosciences
Tsukasa Funane, Heechul Jun, Stephanie Sutoko, Takaomi C. Saido, Akihiko Kandori, Kei M. Igarashi
Summary: Clinical evidence suggests that disruptions in the coordination of sharp-wave ripples (SWRs) between the entorhinal cortex and hippocampal CA1 may serve as an early network symptom that precedes memory impairment in Alzheimer's disease. This study found that the coordination of SWRs between the medial entorhinal cortex (MEC) layers and CA1 was disrupted in amyloid precursor protein knock-in (APP-KI) mice, even before the emergence of spatial memory impairments. These findings provide insight into the underlying brain circuit mechanisms of memory impairments in Alzheimer's disease.
FRONTIERS IN SYSTEMS NEUROSCIENCE
(2022)
Article
Neurosciences
Brianna Vandrey, Stephen Duncan, James A. Ainge
Summary: Episodic memory relies on integrating object information into a spatial framework, with place cells in the hippocampus representing spatial aspects of objects through inputs from the entorhinal cortex. The study found that in cue-rich environments, inputs from the lateral entorhinal cortex (LEC) to the hippocampus led to higher spatial tuning, closer proximity to objects, and greater stability compared to inputs from the medial entorhinal cortex (MEC). In particular, place cells in distal CA1 demonstrated superior spatial tuning and stability, as well as modulated remapping based on proximity to objects.
Article
Neurosciences
Ece Boran, Peter Hilfiker, Lennart Stieglitz, Johannes Sarnthein, Peter Klaver
Summary: The involvement of the medial temporal lobe (MTL) in working memory is controversial, but recent research has found that persistent neural firing in the hippocampus during maintenance is related to workload. This study recorded single neuron firing in 13 epilepsy patients while they performed a visual working memory task. The results showed that performance was almost perfect for low workload and dropped at high workload, suggesting that high workload exceeded working memory capacity. Maintenance neurons in the MTL were identified, and more of them were found in the hippocampus for trials with correct performance compared to incorrect performance. Maintenance neurons showed increased firing in the hippocampus and entorhinal cortex for high workload. Population firing in the entorhinal cortex and hippocampus accurately predicted workload during the maintenance period. The data suggest that persistent neural firing in the MTL supports performance and workload of multiple items in working memory, beyond working memory capacity.
Article
Neurosciences
Nichole R. Bouffard, Ali Golestani, Iva K. Brunec, Buddhika Bellana, Jun Young Park, Morgan D. Barense, Morris Moscovitch
Summary: During navigation, there exist temporal dynamics gradients in the hippocampus and entorhinal cortex. The granularity of information represented in the hippocampus increases along its long axis. Signal stability in the anterior-medial hippocampus is modulated by navigational difficulty and is relevant to behavior.
Article
Physics, Multidisciplinary
Daniel C. McNamee, Kimberly L. Stachenfeld, Matthew M. Botvinick, Samuel J. Gershman
Summary: Medial entorhinal cortex neurons exhibit multiple periodically organized firing fields, forming an internal representation of space. This grid coding is not limited to this cortex region, but also present in other areas like the prefrontal cortex as a general principle. By applying dynamical systems theory, we showed how grid coding can generate diverse sequential reactivations of hippocampal place cells, corresponding to cognitive map traversals. We expanded this model to describe how multiple dynamical systems synthesis can support compositional cognitive computations.
Article
Geriatrics & Gerontology
Yujiro Kose, Yoichi Hatamoto, Rie Takae, Yuki Tomiga, Jun Yasukata, Takaaki Komiyama, Yasuki Higaki
Summary: While overall olfaction was not correlated with physical performance, cognitive function, or brain atrophy, the inability to identify the Japanese orange odor was independently associated with mild medial temporal atrophy in community-dwelling older adults.
Article
Multidisciplinary Sciences
Heather C. Ratigan, Seetha Krishnan, Shai Smith, Mark E. J. Sheffield
Summary: The NR-CA1 pathway actively suppresses fear by disrupting contextual fear memory retrieval in CA1 during fearful freezing behavior, which also reduces fear generalization and accelerates extinction.
NATURE COMMUNICATIONS
(2023)
