Article
Neurosciences
Sam McKenzie, Roman Huszar, Daniel F. English, Kanghwan Kim, Fletcher Christensen, Euisik Yoon, Gyorgy Buzsaki
Summary: The study focuses on how incorporating synthetic hippocampal signals is constrained by preexisting circuit dynamics through optogenetic stimulation of CA1 neurons in mice. Stimulation induced persistent place field remapping and reflected circuit modification through altered spike transmission. The findings suggest that plasticity in recurrent/lateral inhibition may drive learning by rapidly associating existing states.
Article
Multidisciplinary Sciences
Jinhu Kim, Dongseok Park, Na-Young Seo, Taek-Han Yoon, Gyu Hyun Kim, Sang-Hoon Lee, Jinsoo Seo, Ji Won Um, Kea Joo Lee, Jaewon Ko
Summary: Synaptic cell-adhesion molecules (CAMs) play a crucial role in organizing the structure and properties of neural circuits. This study found that Leucine-rich repeat transmembrane protein 3 (LRRTM3) is important for the development of excitatory synapses in hippocampal dentate gyrus (DG) granule neurons. The deletion of LRRTM3 leads to reduced synapse density and synaptic strength in specific projections involving the medial entorhinal cortex (MEC) and DG granule neurons. Additionally, LRRTM3 loss affects neurotransmitter release, excitability of granule neurons, and long-term potentiation of mossy fiber synapses in DG neurons. Silencing the MEC-DG circuits protects against the negative effects of LRRTM3 deficiency on excitatory synapse inputs, granule neuron excitability, and mossy fiber long-term potentiation.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Neurosciences
Sebi V. Rolotti, Mohsin S. Ahmed, Miklos Szoboszlay, Tristan Geiller, Adrian Negrean, Heike Blockus, Kevin C. Gonzalez, Fraser T. Sparks, Ana Sofia Solis Canales, Anna L. Tuttman, Darcy S. Peterka, Boris V. Zemelman, Franck Polleux, Attila Losonczy
Summary: Hippocampal place cells play a crucial role in spatial navigation and memory, and CA1 pyramidal neurons can rapidly form new place fields within a single trial. However, the rapid recruitment of individual neurons into ensemble representations is likely constrained by local feedback circuits. The interaction between circuit dynamics and rapid feature coding remains unexplored.
Article
Biochemistry & Molecular Biology
Glory G. Nasseri, Nusrat Matin, Angela R. Wild, Kira Tosefsky, Stephane Flibotte, R. Greg Stacey, Rocio B. Hollman, Leonard J. Foster, Shernaz X. Bamji
Summary: Dynamic protein S-palmitoylation is critical for neuronal function, development, and synaptic plasticity. Synaptic proteins generally exhibit increased palmitoylation after fear conditioning, while proteins associated with metabolic processes show decreased palmitoylation.
Article
Neurosciences
Zhendong Feng, Lopamudra Saha, Clio Dritsa, Qi Wan, Oleg O. O. Glebov
Summary: The function of the central nervous system is strongly influenced by temperature. This study reveals that hypothermia and hyperthermia trigger bidirectional re-organization of presynaptic architecture in hippocampal neurons, resulting in synaptic strengthening and weakening respectively. Hypothermia also remodels inhibitory postsynaptic scaffold, leading to enlarged sparse synapses enriched with GABAA receptors.
FRONTIERS IN CELLULAR NEUROSCIENCE
(2022)
Review
Biochemistry & Molecular Biology
Ye Wang, Amy K. Y. Fu, Nancy Y. Ip
Summary: In the adult hippocampus, astrocytes, the most common glial cells, play a crucial role in regulating synaptic plasticity. Astrocytes are highly heterogeneous in response to changes in neuronal activity and can modulate synaptic communication through various pathways, ultimately influencing memory performance and cognitive functions. Dysregulation of astrocytic signaling can lead to hippocampal circuit dysfunction and cognitive impairment, as observed in conditions like Alzheimer's disease.
Article
Neurosciences
Fang-Fei Tao, Zi-Yu Wang, Ying Wang, Qian-Ru Lv, Peng-Peng Cai, Hai-Wen Min, Jian-Wei Ge, Chun-Yu Yin, Rui Cheng
Summary: Oxygen therapy plays a vital role in the development of bronchopulmonary dysplasia (BPD), but the effect of hippocampal cyclin-dependent kinase 5 (CDK5) on BPD-associated neurodevelopment deficits is not fully understood. Inhibition of CDK5 overactivation can improve cognitive deficits, neuronal apoptosis, and synaptic plasticity disorders in BPD mice.
CNS NEUROSCIENCE & THERAPEUTICS
(2023)
Article
Multidisciplinary Sciences
Poonam Mishra, Rishikesh Narayanan
Summary: Plasticity in the brain is a common phenomenon, but there are strong systemic constraints that govern simultaneous plasticity in different components. This study reveals a form of neuronal plasticity in rat hippocampal granule cells, characterized by reduced sub-threshold excitability and temporal summation, and enhanced supra-threshold excitability.
Article
Multidisciplinary Sciences
Poonam Mishra, Rishikesh Narayanan
Summary: This paper reveals a form of neuronal plasticity in rat hippocampal granule cells, which is induced by a behaviorally relevant activity pattern. These plastic changes involve multiple channels and depend on calcium influx. These findings contribute to our understanding of the mechanisms underlying information encoding and homeostasis in the brain.
Article
Neurosciences
Sangyoon Y. Ko, Paul W. Frankland
Summary: Memories of events in humans and mammals are encoded by neuronal ensembles in the hippocampus, with some being persistently stored and others modified over time. Adult hippocampal neurogenesis continuously rewires hippocampal circuitry, potentially inducing forgetting of specific stimulus attributes at intermediate stages and silencing hippocampal engrams at more advanced stages.
NEUROSCIENCE LETTERS
(2021)
Article
Cell Biology
Eliott Robert Joseph Levy, Simon Carrillo-Segura, Eun Hye Park, William Thomas Redman, Joserafael Hurtado, Sueyeon Chung, Andreantonio Fenton
Summary: Hippocampus place cells exhibit temporal unreliability and multimodal characteristics, suggesting that the ensemble cofiring spatial coding hypothesis with manifold dynamics is a more accurate representation than hypotheses based on stable place fields. A study on mouse CA1 ensembles showed that while place fields may remap, coactivity relationships generally remain consistent. Decoding location and environment from ensemble activity and cell-pair coactivity relationships is effective and improves with experience.
Article
Cell Biology
Yoav Rechavi, Alon Rubin, Ofer Yizhar, Yaniv Ziv
Summary: Physical exercise is known to improve memory and cognition, but little is known about its effects on neural coding. This study used calcium imaging in freely behaving mice and found that running accelerates the emergence of a more informative spatial code in new environments and increases code stability over time. Interestingly, although runners had a more stable place code overall, their code changed faster when controlling for code quality level. A combination of improved code quality and faster representational drift in runners may explain these results.
Article
Multidisciplinary Sciences
Yuki Aoki, Taiki Yokoi, Shota Morikawa, Nahoko Kuga, Yuji Ikegaya, Takuya Sasaki
Summary: As animals explore environments, hippocampal place cells fire at progressively earlier phases of theta oscillations. This study used optogenetic stimulation to replicate theta phase precession and evaluated its significance on place cell spike patterns. The results showed that place cells activated during phase precession stimulation displayed stronger reactivation and more stable place fields.
Review
Neurosciences
Guillaume Etter, James E. Carmichael, Sylvain Williams
Summary: Oscillations in neural activity, particularly theta rhythms in the hippocampus, play a crucial role in learning and memory. While loss of theta rhythmicity impairs memory, spatial-temporal representations persist in altered hippocampal oscillations. This review aims to investigate the contribution of hippocampal oscillations and single-neuron activity to memory function, and propose hypotheses for how septohippocampal oscillations support memory function without directly contributing to hippocampal sequences.
FRONTIERS IN CELLULAR NEUROSCIENCE
(2023)
Article
Cell Biology
Alberto Lazari, Piergiorgio Salvan, Michiel Cottaar, Daniel Papp, Matthew F. S. Rushworth, Heidi Johansen-Berg
Summary: Evidence suggests that white matter plasticity in humans follows Hebb's rule. Stimulation of cortical areas leads to increased cortical excitability and a myelin marker in the stimulated fiber bundle, indicating the presence of Hebbian plasticity in human white matter fibers.
