Review
Neurosciences
M. B. Parent
Summary: Episodic meal-related memories play a significant role in tracking and controlling eating behavior, and their effects on subsequent intake can last longer than physiological signals. Research suggests that dorsal hippocampal neurons mediate the inhibitory effects of meal-related memory on future intake.
Review
Pharmacology & Pharmacy
Samuel S. Newton, Monica Sathyanesan
Summary: Cognitive deficits are common in psychiatric disorders, such as major depression and schizophrenia, and play a significant role in functional impairment. Targeted treatments for cognitive deficits are limited, with a need for more efficacious treatments. Erythropoietin (Epo) shows promising procognitive effects in psychiatric disorders, supporting a neurotrophic drug development approach.
FRONTIERS IN PHARMACOLOGY
(2021)
Article
Multidisciplinary Sciences
James Delorme, Lijing Wang, Varna Kodoth, Yifan Wang, Jingqun Ma, Sha Jiang, Sara J. Aton
Summary: The study found that sleep loss alters cytosolic ribosomal transcripts while learning almost does not, and the effects of learning are masked by subsequent sleep deprivation. Additionally, sleep deprivation affects fewer membrane-bound ribosomal transcripts, while learning changes more, especially long non-coding RNAs.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Neurosciences
Madeleine Kyrke-Smith, Lenora J. Volk, Samuel F. Cooke, Mark F. Bear, Richard L. Huganir, Jason D. Shepherd
Summary: Research shows that mice lacking the Arc gene do not exhibit deficits in hippocampal long-term potentiation (LTP), indicating that Arc is not necessary for LTP in the hippocampus.
JOURNAL OF NEUROSCIENCE
(2021)
Article
Behavioral Sciences
Rafael Roesler, Marise B. Parent, Ryan T. LaLumiere, Christa K. McIntyre
Summary: Memories of emotionally arousing events tend to endure longer, with the amygdala playing a crucial role in modulating episodic memory consolidation. Studies suggest that the basolateral complex of the amygdala influences hippocampal-dependent memories and synaptic plasticity. Recent optogenetic studies have provided insights into the specific pathways through which the amygdala affects hippocampal regions important for episodic memories.
NEUROBIOLOGY OF LEARNING AND MEMORY
(2021)
Article
Behavioral Sciences
S. B. Briggs, C. B. Ware, K. Sharma, S. C. Davis, R. T. Lalumiere, M. B. Parent
Summary: Research shows that dorsal hippocampal (dHC) glutamatergic neurons play a crucial role in inhibiting future intake by consolidating memories of previous meals. Inhibiting these neurons shortly after a meal increases the likelihood and amount of subsequent intake, while delayed inhibition has no effect on future intake.
NEUROBIOLOGY OF LEARNING AND MEMORY
(2021)
Article
Neurosciences
Karl Peter Giese
Summary: Autophosphorylation of calcium/calmodulin-dependent kinase II (CaMKII) plays a critical role in synaptic potentiation by allowing kinase signaling to outlast NMDA receptor-dependent calcium influx. However, the role of CaMKII is conditional, depending on the developmental stage and location of the synapse.
Article
Biochemistry & Molecular Biology
Candice M. Roux, Pierre Lecouflet, Jean-Marie Billard, Elise Esneault, Marianne Leger, Pascale Schumann-Bard, Thomas Freret
Summary: Acute hippocampal slice preparations have been commonly used in studying the anti-amnesic properties of drug candidates on long-term potentiation (LTP). Genetic background is crucial in experimental design, considering the availability of various transgenic mouse models. In this study, LTP was compared between inbred and outbred mice, showing reduced LTP magnitude in outbred mice due to lower responsiveness to theta-frequency during conditioning stimuli. Overall, this study highlights the importance of considering animal models in electrophysiological experiments.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Neurosciences
Timothy Tadros, Maxim Bazhenov
Summary: Relational memory is critical for mammalian reasoning. Sleep plays a crucial role in offline processing and improving the ability to make indirect associations.
JOURNAL OF NEUROSCIENCE
(2022)
Article
Multidisciplinary Sciences
Virginie Sterpenich, Mojca K. M. van Schie, Maximilien Catsiyannis, Avinash Ramyead, Stephen Perrig, Hee-Deok Yang, Dimitri Van De Ville, Sophie Schwartz
Summary: Sleep promotes memory consolidation, with neural representations of rewarded experiences undergoing privileged reactivation during sleep, favoring their consolidation.
NATURE COMMUNICATIONS
(2021)
Article
Biochemistry & Molecular Biology
Marlene F. Pereira, Ines M. Amaral, Catia Lopes, Catarina Leitao, Daniela Madeira, Joao P. Lopes, Francisco Q. Goncalves, Paula M. Canas, Rodrigo A. Cunha, Paula Agostinho
Summary: The study shows that L-alpha-aminoadipate (L-AA) affects astrocytes differently and impairs synaptic plasticity and memory. Injection of L-AA negatively impacts hippocampal long-term potentiation (LTP) and hippocampal-dependent memory in mice. D-serine administration can partially rescue the reduction in hippocampal LTP induced by L-AA exposure.
Article
Endocrinology & Metabolism
Leigang Song, Huan Chen, Dan Qiao, Bohan Zhang, Fangzhen Guo, Yizhou Zhang, Chang Wang, Sha Li, Huixian Cui
Summary: Androgens regulate learning and memory in mice through ZIP9, which is mediated by the ERK1/2-eIF4E pathway. This study provides new experimental evidence for the improvement of learning and memory in Alzheimer's disease through androgen supplementation.
FRONTIERS IN ENDOCRINOLOGY
(2023)
Review
Neurosciences
Akihiro Goto
Summary: This article discusses the function of synaptic plasticity in memory consolidation, focusing mainly on the hippocampus and cortex.
NEUROSCIENCE RESEARCH
(2022)
Review
Neurosciences
Yanis Inglebert, Dominique Debanne
Summary: The importance of considering physiological levels of extracellular calcium concentration in studying functional plasticity is discussed in this study.
FRONTIERS IN CELLULAR NEUROSCIENCE
(2021)
Article
Clinical Neurology
Hui Wang, Liang Liang, Can Yang, Ling Xiao, Huiling Wang, Gaohua Wang, Zhixian Zhu
Summary: This study found that low-density lipoprotein receptor-related protein 1 (LRP1) in the hippocampus of rats is positively correlated with depressive-like behaviors. Administration of LRP1 improved depressive-like behaviors, while LRP1 knockdown alleviated the inhibition of synaptic plasticity induced by chronic unpredicted mild stress (CUMS). Furthermore, LRP1 knockdown increased synaptic plasticity through microtubule dynamics and activation of the Akt/GSK-3 beta signaling pathway. These findings suggest that LRP1 may serve as a potential therapeutic target for depression.
JOURNAL OF AFFECTIVE DISORDERS
(2023)
Article
Neurosciences
William D. Marks, Naoki Yamamoto, Takashi Kitamura
Summary: This review provides updates on recent anatomical discoveries related to the EC-HPC network, discussing important neural circuits critical for memory formation. It also examines the complementary roles of multiple medial entorhinal cortical inputs, including newly discovered circuits, in the temporal and spatial aspects of memory. Finally, the integration of temporal and contextual memory information in HPC cornu ammonis 1 cells is discussed, offering new insights into neural circuit mechanisms for segregating and integrating the temporal and spatial aspects of memory encoding in the EC-HPC networks.
EUROPEAN JOURNAL OF NEUROSCIENCE
(2021)
Article
Neurosciences
Joseph Terranova, Jun Yokose, Hisayuki Osanai, William D. Marks, Jun Yamamoto, Sachie K. Ogawa, Takashi Kitamura
Summary: The ability to vicariously experience fear in others, known as observational fear (OF), is crucial for survival and functioning in society. This study reveals that the hippocampal-basolateral amygdala (HPC-BLA) circuits in mice, not involving the anterior cingulate cortex, mediate the experience-dependent OF. Dorsal HPC neurons encode fear memory engram cells in the BLA that are critical for OF, while ventral HPC neurons respond to familiar aversive situations in others to reactivate fear memory engram cells in the BLA and elicit OF. This study provides new insights into empathic behaviors and their neural mechanisms.
Article
Multidisciplinary Sciences
Akinobu Suzuki, Sakurako Kosugi, Emi Murayama, Eri Sasakawa, Noriaki Ohkawa, Ayumu Konno, Hirokazu Hirai, Kaoru Inokuchi
Summary: Animals refer to past experiences when processing current sensory inputs, and update previous memories through neural networks. This study reveals that a cellular ensemble in the posterior parietal cortex of mice interacts with the anterior cingulate cortex through a circuit to update memory by incorporating past and current information.
NATURE COMMUNICATIONS
(2022)
Review
Behavioral Sciences
William D. Marks, Jun Yokose, Takashi Kitamura, Sachie K. Ogawa
Summary: Contextual learning is crucial for episodic memory and adapting to different environments. This article reviews the behavioral foundations, neural centers, and physiological processes involved in contextual memory. It discusses the role of ensemble activity, remapping, pattern separation, and completion in processing contextual information, and explores the potential contribution of the engram assembly to contextual memory.
FRONTIERS IN BEHAVIORAL NEUROSCIENCE
(2022)
Article
Multidisciplinary Sciences
Mohamed H. Aly, Kareem Abdou, Reiko Okubo-Suzuki, Masanori Nomoto, Kaoru Inokuchi
Summary: The passive priming of prior knowledge to assimilate ongoing experiences is essential for advanced cognitive processing. This study investigates the neural dynamics of memory assimilation and the potential creativity of the idling brain. The findings suggest that assimilating pertinent memories through coreactivation during sleep represents the neural underpinnings of sleep-triggered implicit cortical learning.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Editorial Material
Neurosciences
Ali Choucry, Khaled Ghandour, Kaoru Inokuchi
Summary: This article investigates a specific neuromodulatory circuit in the hippocampus that is involved in contextual memory linking, but not formation.
Article
Biology
Maha E. Wally, Masanori Nomoto, Kareem Abdou, Emi Murayama, Kaoru Inokuchi
Summary: Short-term memory (STM) can be optogenetically retrieved at a time point when natural recall is not possible, revealing the long-term existence of an STM engram. Re-training leads to natural long-term recall, indicating facilitated consolidation. Protein synthesis, NMDAR activity, and NREM sleep play important roles in the long-term storage of an STM trace.
COMMUNICATIONS BIOLOGY
(2022)
Article
Multidisciplinary Sciences
Masanori Nomoto, Emi Murayama, Shuntaro Ohno, Reiko Okubo-Suzuki, Shin-ichi Muramatsu, Kaoru Inokuchi
Summary: The hippocampus utilizes reverberatory activity to link conditioned and unconditioned stimuli and avoid interference during sensory inputs. It is still unknown how the hippocampus executes these processes simultaneously during learning.
NATURE COMMUNICATIONS
(2022)
Article
Neurosciences
Masanori Nomoto, Noriaki Ohkawa, Kaoru Inokuchi, Naoya Oishi
Summary: This study found that NRs in the hippocampal CA3 are crucial for supporting hippocampal functions, such as pattern completion and reverberatory association of sensory inputs. Previous research showed that synchronous activation of distinct cell populations in CA3 could result in the artificial association of independent events, indicating the role of NRs in mediating memory event association in CA3. However, it is still unclear whether NRs in CA3 are essential for the artificial association of memory events stored in CA3 ensembles.
Article
Biology
Akiyo Kameyama, Hirotaka Asai, Masanori Nomoto, Shuntaro Ohno, Khaled Ghandour, Noriaki Ohkawa, Yoshito Saitoh, Mitsuaki Yamazaki, Kaoru Inokuchi
Summary: General anesthesia can cause retrograde amnesia by suppressing neuronal ensemble activity in the hippocampus. In the experiments, sevoflurane treatment impaired memory and prevented neural activity in the CA1 region. Further analysis revealed a reduction in the reactivation of neuronal ensembles caused by sevoflurane treatment.
Review
Biochemistry & Molecular Biology
Hisayuki Osanai, Indrajith R. R. Nair, Takashi Kitamura
Summary: Episodic memory, crucial to our daily lives, relies on the entorhinal cortex (EC) and hippocampus (HPC). Recent studies have revealed the complementary roles of superficial and deep layers of neurons in memory formation and recall.
JOURNAL OF NEUROCHEMISTRY
(2023)
Correction
Neurosciences
Masanori Nomoto, Noriaki Ohkawa, Kaoru Inokuchi, Naoya Oishi
Article
Biochemical Research Methods
Hisayuki Osanai, Jun Yamamoto, Takashi Kitamura
Summary: Independent component analysis (ICA) is used to extract noise components from local field potential data, and the reconstructed electromyography (EMG) signals, called IC-EMG, can be used to measure animal behavior states consistently with directly measured EMG. This method offers advantages for precise and long-term behavioral measurement in a wide range of in vivo electrophysiology experiments.
CELL REPORTS METHODS
(2023)
Article
Multidisciplinary Sciences
Joseph I. I. Terranova, Jun Yokose, Hisayuki Osanai, Sachie K. K. Ogawa, Takashi Kitamura
Summary: Observers learn to fear the context in which they witnessed a demonstrator's aversive experience, called observational contextual fear conditioning (CFC). The neural mechanisms governing recall of the observational CFC memory from different perspectives remain unclear. Recent memory is recalled in the observer's context, while remote memory is recalled in both observer and demonstrator contexts. Dorsal hippocampus activity is required for recent memory recall in the observer's context, while the medial prefrontal cortex (mPFC)-basolateral amygdala pathway is required for remote memory recall in both contexts. Different mPFC subpopulations regulate remote recall in each context.
NATURE COMMUNICATIONS
(2023)
Meeting Abstract
Neurosciences
Takashi Kitamura, Joseph Terranova, Sachie Ogawa
NEUROPSYCHOPHARMACOLOGY
(2022)
