Article
Biochemistry & Molecular Biology
Laurel Watkins de Jong, Mohammadreza Mohagheghi Nejad, Euisik Yoon, Sen Cheng, Kamran Diba
Summary: Recurrent connectivity and feedback inhibition from inhibitory neurons play crucial roles in determining the dynamics and computational properties of neuronal circuits. Through optogenetic manipulations and large-scale unit recordings, paradoxical responses were observed in both CA1 and CA3 regions of the hippocampus, where subsets of cells increased firing during photoinhibition while others decreased firing during photoexcitation. These paradoxical responses were more prominent in CA3 and simulations confirmed that both CA1 and CA3 hippocampal regions exhibit inhibition-stabilized networks with strong recurrent excitation.
Article
Neurosciences
Olivia A. Shipton, Clara S. Tang, Ole Paulsen, Mariana Vargas-Caballero
Summary: The study shows that both A beta and tau protein play a role in the development of Alzheimer's disease. A beta affects synaptic deficits in wild-type mice, but not in mice without tau protein. Additionally, CA3-CA1 synapses in the hippocampus with presynaptic axons from the left CA3 are more vulnerable to A beta.
ACTA NEUROPATHOLOGICA COMMUNICATIONS
(2022)
Article
Cell Biology
Junfeng Su, Fengwen Huang, Yu Tian, Ran Tian, Qianqian Gao, Stephen Temitayo Bello, Dingxaun Zeng, Peter Jendrichovsky, C. Geoffrey Lau, Wenjun Xiong, Daiguan Yu, Micky Tortorella, Xi Chen, Jufang He
Summary: This study reveals the critical role of cholecystokinin (CCK) in heterosynaptic neuromodulation from the medial entorhinal cortex (MEC) to the hippocampus, affecting CA3-CA1 LTP and space-related performance.
Article
Neurosciences
Isabel Espadas, Oscar Ortiz, Patricia Garcia-Sanz, Adrian Sanz-Magro, Samuel Alberquilla, Oscar Solis, Jose Maria Delgado-Garcia, Agnes Gruart, Rosario Moratalla
Summary: The genetic inactivation of D2R impairs spatial memory, associative learning, and classical conditioning of eyelid responses, as well as reduces activity-dependent synaptic plasticity in the hippocampal CA1-CA3 synapse. These findings demonstrate the key role of D2R in regulating hippocampal plasticity changes and affecting the acquisition and consolidation of spatial and associative forms of memory.
Article
Behavioral Sciences
Wei Sun, Peidong Liu, Chunzhi Tang, Lei An
Summary: The study found that melamine reduced synchronization of neural oscillations and disrupted the directional flow of neural information in the hippocampal regions. Additionally, melamine treatment decreased acetylcholine expression and increased acetylcholinesterase activity in the hippocampus of rats.
FRONTIERS IN BEHAVIORAL NEUROSCIENCE
(2021)
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)
Article
Cell Biology
Erika Atucha, Shih-Pi Ku, Michael T. Lippert, Magdalena M. Sauvage
Summary: This study focuses on understanding why some people have clearer memories of events and why memory becomes less precise over time. The researchers found that specific neuroanatomical pathways within the medial temporal lobe (MTL) of the brain play a role in determining the precision of recalled memories throughout a person's life. The hippocampal subfield CA1 is crucial for retrieving the essence of events, receiving support from MTL cortical areas (MEC, LEC, PER, and POR) for recalling the most remote memories. On the other hand, a reduction in activity in the CA3 subfield is associated with the loss of memory precision over time. The study suggests that a shift between specific MTL subnetworks over time may be a fundamental mechanism for memory consolidation.
Article
Biology
Koichiro Kajikawa, Brad K. Hulse, Athanassios G. Siapas, Evgueniy Lubenov, Adrien Peyrache
Summary: The study found that in awake mice, hippocampal ripples are influenced by the brain state and ripple modulation, with different responses to depolarization caused by entorhinal input in different hippocampal subfields. There is evident inhibition in CA3 during the ripple buildup, while DG and CA1 neurons exhibit depolarization transients.
Article
Multidisciplinary Sciences
Hefei Guan, Steven J. Middleton, Takafumi Inoue, Thomas J. McHugh
Summary: The bilateral projection from CA3 plays a key role in coordinating CA1 spatial coding across hemispheres. Blocking synaptic transmission at CA3 terminals leads to decreased ripple synchronization between left and right CA1, and results in less coordinated neuronal ensemble activity across hemispheres during exploration and rest.
NATURE COMMUNICATIONS
(2021)
Article
Neurosciences
Tobias Bock, Adrian Negrean, Steven A. Siegelbaum
Summary: Synaptic inputs targeting distal dendrites can amplify local dendritic spikes, but these spikes are often weak due to dendritic cable properties. Despite this, they are implicated in memory storage, sensory perception, and place field formation. Somatic depolarization can enhance dendritic spike propagation, leading to enhanced memory specificity and long-term synaptic plasticity in hippocampal-dependent spatial representations and learning.
JOURNAL OF NEUROSCIENCE
(2022)
Article
Neurosciences
Rolando Torrado-Arevalo, Julieta Troncoso, Alejandro Munera
Summary: Facial nerve axotomy induces changes in the central nervous system beyond facial motoneurons, affecting sensorimotor cortex and hippocampal-dependent memory tasks. In animal experiments, it was found that peripheral axotomy affects basal transmission and long-term plasticity of CA3-CA1 synapses, with enhanced release probability and impairment in long-term potentiation induction. These synaptic changes may explain impairments in hippocampal-dependent memory tasks and suggest a direct hippocampal involvement in sensorimotor integration.
Article
Neurosciences
Aida Maziar, Tristian N. R. H. Y. Critch, Sourav Ghosh, Vishaal Rajani, Cassandra M. Flynn, Tian Qin, Camila Reinhardt, Kwun Nok Mimi Man, Amy Lee, Johannes W. Hell, Qi Yuan
Summary: Aging is linked to cognitive decline and memory loss. In rats, aging leads to changes in neuronal excitability in the piriform cortex and hippocampus, affecting learning abilities.
Article
Neurosciences
Xiaoxiao Lin, Neeyaz Cyrus, Brenda Avila, Todd C. Holmes, Xiangmin Xu
Summary: Traditionally, hippocampal CA3 is thought to be part of a unidirectional feedforward trisynaptic pathway. However, recent studies using genomic and viral tracing techniques have revealed that the anatomical connectivity of CA3 and the trisynaptic pathway is more complex than expected, with cell type-specific input gradients throughout the hippocampal structure. These studies also identified noncanonical circuit connections between CA3 inhibitory neurons and ventral CA1, subiculum complex, and other brain regions, suggesting a more intricate network than previously thought. Understanding these novel connections provides a basis for further investigating the function of CA3 inhibitory neurons.
JOURNAL OF COMPARATIVE NEUROLOGY
(2023)
Article
Neurosciences
Karen A. Bell, Rayne Delong, Priyodarshan Goswamee, A. Rory McQuiston
Summary: The study reveals that the entorhinal cortex alvear pathway provides major excitatory inputs to hippocampal CA1, primarily affecting CA1 function through feedforward inhibition of select interneuron subtypes.
Article
Neurosciences
Emma L. Twait, Kim Blom, Huiberdina L. Koek, Maarten H. T. Zwartbol, Rashid Ghaznawi, Jeroen Hendrikse, Lotte Gerritsen, Mirjam I. Geerlings
Summary: This study used high-field 7T MRI to explore the association between psychosocial factors and hippocampal (subfield) volumes. The results showed that depression and anxiety were not associated with specific hippocampal (subfield) volumes, while childhood maltreatment and recent stressful life events may have an impact on hippocampal volume. Additionally, low social support was associated with smaller CA3 volume.
HUMAN BRAIN MAPPING
(2023)
Article
Behavioral Sciences
Vera Flasbeck, Erika Atucha, Nozomu H. Nakamura, Motoharu Yoshida, Magdalena M. Sauvage
BEHAVIOURAL BRAIN RESEARCH
(2018)
Article
Geriatrics & Gerontology
David Berron, Katja Neumann, Anne Maass, Hartmut Schuetze, Klaus Fliessbach, Verena Kiven, Frank Jessen, Magdalena Sauvage, Dharshan Kumaran, Emrah Duezel
NEUROBIOLOGY OF AGING
(2018)
Article
Behavioral Sciences
Vera Flasbeck, Erika Atucha, Nozomu H. Nakamura, Motoharu Yoshida, Magdalena M. Sauvage
BEHAVIOURAL BRAIN RESEARCH
(2018)
Article
Biochemical Research Methods
Magdalena Sauvage, Takashi Kitsukawa, Erika Atucha
JOURNAL OF NEUROSCIENCE METHODS
(2019)
Article
Neurosciences
Maria Jesus Valero-Aracama, Antonio Reboreda, Alberto Arboit, Magdalena Sauvage, Motoharu Yoshida
Summary: Persistent firing is considered a cellular correlate of working memory, where it is shown to be supported by cholinergic receptor activation in hippocampal CA1 pyramidal cells and suppressed by noradrenaline (NA). The inhibitory effect of NA on persistent firing is mediated through the cAMP-PKA pathway and activation of beta 1 and/or beta 3 adrenergic receptors, with high levels of NA and cAMP implicated in working memory decline under conditions such as high stress, aging, and schizophrenia.
Article
Multidisciplinary Sciences
Marie Oule, Erika Atucha, Tenyse M. Wells, Tamar Macharadze, Magdalena M. Sauvage, Michael R. Kreutz, Jeffrey Lopez-Rojas
Summary: The Kv4.2 channels selectively modulate the excitability of medial dendrites of dentate GCs, impacting the spatial pattern separation capability of animals.
Article
Multidisciplinary Sciences
Liv Mahnke, Erika Atucha, Eneko Pina-Fernandez, Takashi Kitsukawa, Magdalena M. Sauvage
Summary: This study investigated the relationship between the hippocampus and the LEC and PER in recognition memory, finding that hippocampal lesions enhance LEC activity during familiarity judgments but not in PER. These findings suggest that different mechanisms support familiarity in LEC and PER.
SCIENTIFIC REPORTS
(2021)
Article
Neurosciences
Camila Silveira Agostino, Christian Merkel, Felix Ball, Peter Vavra, Hermann Hinrichs, Toemme Noesselt
Summary: The study investigates the neural basis of visible and occluded changes in motion direction using retinotopic maps and multivariate pattern analysis. The findings suggest that low-level visual areas play a role in mentally representing motion trajectory during occlusion.
HUMAN BRAIN MAPPING
(2023)
Article
Education & Educational Research
Peter Vavra, Leo Sokolovic, Emanuele Porcu, Pablo Ripolles, Antoni Rodriguez-Fornells, Toemme Noesselt
Summary: Incentives can decrease performance by undermining intrinsic motivation. How the interplay of external reinforcers and internal self-regulation influences memory processes is less known. This study investigated their interaction on memory performance in learning new-word meanings, and found that external reinforcers can selectively impair memories depending on what is being learned and whether internal self-regulated processes are already established.
NPJ SCIENCE OF LEARNING
(2023)
Article
Psychology, Clinical
Henrik Kessler, Anna-Christine Schmidt, Ella L. James, Simon E. Blackwell, Marcel von Rauchhaupt, Katharina Harren, Aram Kehyayan, Ian A. Clark, Magdalena Sauvage, Stephan Herpertz, Nikolai Axmacher, Emily A. Holmes
JOURNAL OF BEHAVIOR THERAPY AND EXPERIMENTAL PSYCHIATRY
(2020)
Article
Psychology, Multidisciplinary
Peter Vavra, Luke J. Chang, Alan G. Sanfey
FRONTIERS IN PSYCHOLOGY
(2018)