Article
Behavioral Sciences
Christopher M. Dillingham, Michal M. Milczarek, James C. Perry, Seralynne D. Vann
Summary: Research has shown that the mammillary body-anterior thalamic axis plays a crucial role in memory and amnesia, affecting contextual and temporal memory processing. The projections from the mammillothalamic tract have significant distal influence over thalamo-cortical and hippocampo-cortical interactions.
NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS
(2021)
Article
Neurosciences
Mengxuan Gao, Asako Noguchi, Yuji Ikegaya
Summary: Neurons in the retrosplenial cortex (RSC) exhibit short-term intrinsic plasticity, in which delayed spikes in response to current injection can be shortened by a preceding depolarization. This priming-induced sensitization lasts for more than 3 seconds, potentially modulating subsequent information integration in RSC circuits. Activation of subicular afferents replicates this facilitatory priming effect, suggesting a role for subicular inputs in regulating RSC neuronal activity.
JOURNAL OF PHYSIOLOGY-LONDON
(2021)
Article
Geriatrics & Gerontology
Martina Laczo, Lukas Martinkovic, Ondrej Lerch, Jan M. Wiener, Jana Kalinova, Veronika Matuskova, Zuzana Nedelska, Martin Vyhnalek, Jakub Hort, Jan Laczo
Summary: This study assessed spatial navigation performance in AD aMCI and non-AD aMCI patients, and examined the associations between navigation performance and MRI measures of brain atrophy as well as CSF biomarkers related to AD pathology.
FRONTIERS IN AGING NEUROSCIENCE
(2022)
Article
Anatomy & Morphology
Thu-Huong Hoang, Denise Manahan-Vaughan
Summary: Hippocampal afferent inputs enable the discrimination of item identity and spatial location in spatial representation, supported by structures like the retrosplenial cortex. Learning-facilitated long-term depression (LTD) promotes the expression of hippocampal synaptic plasticity. A study using gene-tagging techniques found that learning-facilitated LTD results in subfield-specific information encoding in the hippocampus and the retrosplenial cortex, revealing a novel role of the latter in item-place learning.
BRAIN STRUCTURE & FUNCTION
(2023)
Article
Multidisciplinary Sciences
Ingrid M. Esteves, HaoRan Chang, Adam R. Neumann, Bruce L. McNaughton
Summary: Systems-level memory consolidation involves the conversion of memories from hippocampus-dependent to hippocampus-independent forms. Little is known about the neural codes at the cellular ensemble level in consolidated memory. This study shows that while a novel virtual environment is not learned or represented in the superficial cortex after severe hippocampal damage, pre-operatively learned memories and their corresponding neural ensemble representations are preserved in cortical layers II-III, providing insights for future research on the cellular mechanisms of memory consolidation.
Article
Neurosciences
Xiao-Jun Xiang, Sheng-Qiang Chen, Xue-Qin Zhang, Chang-Hui Chen, Shun-Yu Zhang, Hui-Ru Cai, Song-Lin Ding
Summary: This study has discovered a possible equivalent of the primate posterior cingulate cortex (A23) in rodents, which can aid in modeling related circuits and diseases in these animals.
FRONTIERS IN NEUROSCIENCE
(2023)
Article
Neurosciences
Jacob Ziontz, Jenna N. Adams, Theresa M. Harrison, Suzanne L. Baker, William J. Jagust
Summary: The study found that functional connectivity between the hippocampus and retrosplenial cortex is associated with tau pathology in the medial parietal lobe, potentially playing a key role in cognitive decline. On the other hand, connectivity between the entorhinal cortex and retrosplenial cortex is not related to tau pathology. Overall, stronger connectivity between the hippocampus and retrosplenial cortex is associated with medial parietal lobe tau pathology, and this interaction affects episodic memory performance.
JOURNAL OF NEUROSCIENCE
(2021)
Review
Neurosciences
Taiping Zeng, Bailu Si, Jianfeng Feng
Summary: This study introduces a new theory for constructing cognitive maps, describing a range of cell types including boundary vector cells, border cells, and geometry cells that encode the geometric layout of space.
PROGRESS IN NEUROBIOLOGY
(2022)
Article
Psychology, Experimental
Xing Xing, Jeffrey A. Saunders
Summary: This study tested whether connections between non-spatial properties can distort judgments about spatial distance. The results showed that similar houses were drawn closer on reconstructed maps, and pairwise distance judgments were smaller for similar houses. These findings support theories that space is represented with other properties, suggesting that the mechanism for encoding space in the hippocampal-entorhinal system has a broader function.
Editorial Material
Biochemistry & Molecular Biology
Kaue Machado Costa, Geoffrey Schoenbaum
Summary: Hippocampal place cells represent spatial locations, and a recent study shows that place cells in the intermediate hippocampus remap their fields following changes in reward, shedding light on how they incorporate associations between locations and specific outcomes.
Article
Behavioral Sciences
John P. Aggleton, Seralynne D. Vann, Shane M. O'Mara
Summary: Understanding the neural basis of episodic memory requires an appreciation of the significance of the fornix. Through studying patients with colloid cysts, it was found that there is a consistent relationship between mammillary body volume and episodic memory recall. Additionally, a dissociation between recollective-based recognition and familiarity-based recognition was observed, highlighting the importance of the mammillary body-anterior thalamic nuclei axis and the hippocampus for episodic memory.
Article
Neurosciences
Xu Huang, Magdalene Isabell Schlesiger, Isabel Barriuso-Ortega, Christian Leibold, Duncan Archibald Allan MacLaren, Nina Bieber, Hannah Monyer
Summary: The lateral entorhinal cortex (LEC) is a crucial cortical input area to the hippocampus, responsible for associative object-place-context memories. Recent studies have found a gradient of spatial selectivity along the antero-posterior axis of the LEC, with distinct spatial maps generated for different contexts. Additionally, there are neurons in the LEC that encode both space and objects conjunctively.
Editorial Material
Biochemistry & Molecular Biology
Mark H. Plitt, Lisa M. Giocomo
Summary: The recent study using new holographic optogenetic stimulation technology provides direct evidence that hippocampal place cell activity is sufficient to drive memory and navigation-related behaviors.
Review
Neurosciences
Oliver Baumann, Jason B. Mattingley
Summary: Spatial navigation is a crucial everyday skill, and functional magnetic resonance imaging has provided insights into the neural underpinnings of navigation abilities beyond the hippocampus, implicating other brain regions such as the parahippocampal cortex, retrosplenial cortex, dorsal striatum, and posterior parietal cortex. These regions play important complementary roles in regulating successful way-finding behavior.
Editorial Material
Neurosciences
Isabel I. C. Low, Lisa M. Giocomo
Summary: Pettit, Yuan, and Harvey discovered that hippocampal spatial maps degrade when mice voluntarily disengage from a navigation task, even without changes in sensory or self-motion cues. This suggests that internal state might play an active role in supporting navigational coding and spatial memory.
NATURE NEUROSCIENCE
(2022)