Article
Neurosciences
Joana Freitas Costa, Monica Dines, Karishma Agarwal, Raphael Lamprecht
Summary: Long-term memory formation leads to enduring changes in neuronal morphology, including an increase in the volume and length of dendritic branches and dendritic spines. Fear conditioning induces such changes in the basolateral amygdala, but activation of Rac1 during fear conditioning impairs fear memory formation by preventing these changes. These results highlight the importance of neuronal morphology in fear memory formation.
NEUROPSYCHOPHARMACOLOGY
(2023)
Article
Biology
Jesus Perez-Ortega, Tzitzitlini Alejandre-Garcia, Rafael Yuste
Summary: Neuronal ensembles, identified as coactive groups of neurons in cortical activity, can last for weeks in the visual cortex of awake mice, with some ensembles maintaining activity for up to 46 days and displaying stronger functional connectivity.
Article
Biology
Maximilian F. Eggl, Thomas E. Chater, Janko Petkovic, Yukiko Goda, Tatjana Tchumatchenko
Summary: This study reveals how seemingly spontaneous synaptic fluctuations and local plasticity both contribute to population-level synaptic dynamics.
COMMUNICATIONS BIOLOGY
(2023)
Review
Cell Biology
Raphael Lamprecht
Summary: The study suggests that long-term memory formation creates lasting changes in neuronal morphology within a specific neural network, and these changes may be correlated with memory strength. The formation and elimination of dendritic spines, as well as finer morphological changes in spines, are regulated by the actin cytoskeleton. Maintaining a stable actin cytoskeleton network within spines supports long-lasting spine structure and the maintenance of long-term memory.
Article
Cell Biology
Carolina Flores-Munoz, Francisca Garcia-Rojas, Miguel A. Perez, Odra Santander, Elena Mery, Stefany Ordenes, Javiera Illanes-Gonzalez, Daniela Lopez-Espindola, Arlek M. Gonzalez-Jamett, Marco Fuenzalida, Agustin D. Martinez, Alvaro O. Ardiles
Summary: Enhanced activity and overexpression of Pannexin 1 (Panx1) channels contribute to neuronal pathologies. The absence of Panx1 in the adult brain promotes structural and functional modifications in hippocampal synapses, preserving spontaneous activity. These modifications are related to actin-cytoskeleton dynamics and Rho GTPases.
Article
Cell Biology
Luca Franchini, Jennifer Stanic, Marta Barzasi, Elisa Zianni, Daniela Mauceri, Monica Diluca, Fabrizio Gardoni
Summary: This study demonstrates a key role for Rph3A in the modulation of structural synaptic plasticity at hippocampal synapses, which correlates with its interactions with both NMDARs and AMPARs.
Article
Cell Biology
Lianwei Mu, Jiajia Cai, Boya Gu, Laikang Yu, Cui Li, Qing-Song Liu, Li Zhao
Summary: Alzheimer's disease is characterized by learning and memory deficits, and treadmill exercise can enhance synaptic plasticity in mouse models. This study found that 12 weeks of treadmill exercise improved spatial working memory in AD mice and increased synapse numbers and structural parameters. Treadmill exercise may prevent decline in learning and memory by strengthening structural synaptic plasticity in AD mice.
Article
Multidisciplinary Sciences
Michael Wenzel, Alexander Leunig, Shuting Han, Darcy S. Peterka, Rafael Yuste
Summary: Prolonged medically induced coma (pMIC) is routinely carried out in intensive care medicine, leading to cognitive impairment. A study on adolescent and mature mice shows that pMIC affects object recognition and is associated with enhanced synaptic turnover, with increased synapse formation during pMIC and synaptic loss post-anesthesia. These results demonstrate significant side effects of prolonged anesthesia on neural circuit structure.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Neurosciences
Anna Longatti, Luisa Ponzoni, Edoardo Moretto, Giorgia Giansante, Norma Lattuada, Maria Nicol Colombo, Maura Francolini, Mariaelvina Sala, Luca Murru, Maria Passafaro
Summary: Rho GTPases, specifically ARHGAP22, play a critical role in regulating actin dynamics and synaptic function in the CNS. Loss of ARHGAP22 leads to RAC1 hyperactivity and synaptic defects in dendritic spine density, molecular composition, and plasticity, resulting in cognitive impairment and reduced anxiety-like behavior in mice. Inhibiting RAC1 activity restores synaptic plasticity in ARHGAP22 KO mice, highlighting the importance of ARHGAP22 in hippocampal excitatory synapse formation and function, as well as in learning and memory behaviors.
MOLECULAR NEUROBIOLOGY
(2021)
Article
Cell Biology
Yongchuan Zhu, Marco Uytiepo, Eric Bushong, Matthias Haberl, Elizabeth Beutter, Frederieke Scheiwe, Weiheng Zhang, Lyanne Chang, Danielle Luu, Brandon Chui, Mark Ellisman, Anton Maximov
Summary: The study shows that experience is not necessary for the development of synaptic morphology and the arrangement of different connections in local networks is stochastic. Loss of activity increases the variability in synaptic structure size, but does not disrupt their alignment. These results demonstrate that mechanisms for the structural diversity of neuronal synapses are intrinsic.
Article
Biochemical Research Methods
Moritz F. P. Becker, Christian Tetzlaff
Summary: The study investigates the principles underlying the maintenance of synaptic changes during the early phase of LTP, suggesting that the interplay between specific features of postsynaptic receptor trafficking is crucial. By formalizing a biophysical model and making predictions, it is concluded that synaptic changes can be sustained for hours when influenced by structural changes of the spine, increased trafficking from recycling endosomes, and cooperative binding of receptors.
PLOS COMPUTATIONAL BIOLOGY
(2021)
Article
Computer Science, Artificial Intelligence
Marifi Guler
Summary: The morphology of dendritic arbor and synaptic efficacy map strongly influence the transformation of synaptic input into action potential in nerve cells; the multiplicity of dendritic branches enables a single cell to act as a highly nonlinear processing element; the occurrence of synaptic clustering boosts the generalization efficiency of the neural model.
NEURAL COMPUTATION
(2021)
Article
Neurosciences
Haruo Kasai, Hasan Ucar, Yuichi Morimoto, Fumihiro Eto, Hitoshi Okazaki
Summary: Dendritic spines, the postsynaptic component of most excitatory synapses, have been found to have a novel feature of pushing presynaptic terminals with muscle-like force, resulting in increased glutamate release for up to 20 minutes. This mechanical transmission shares similarities with short-term potentiation (STP) and may play a role in short-term and working memory. Therefore, spine synapses contribute to the force of learning and leave structural traces for both short and long-term memories.
CURRENT OPINION IN NEUROBIOLOGY
(2023)
Review
Clinical Neurology
Ja Eun Choi, Bong-Kiun Kaang
Summary: The brain has the ability to transform experiences into anatomic maps and integrate massive amounts of information to form new memories. Dendritic spines are believed to be the structural basis of information storage and are associated with learning and memory. Advancements in techniques allow for more precise investigation of dendritic spines and provide clues about how memories reside in them.
Article
Psychiatry
Alireza Chenani, Ghabiba Weston, Alessandro F. Ulivi, Tim P. Castello-Waldow, Rosa-Eva Huettl, Alon Chen, Alessio Attardo
Summary: Stress exposure can adversely affect brain structure and function, leading to cognitive deficits and increased risk for psychiatric disorders. This study used longitudinal deep-brain optical imaging to explore the impact of stress exposure on activity patterns and structural plasticity of dorsal CA1 pyramidal neurons, as well as hippocampal-dependent learning and memory. The findings revealed that repeated stress increased neuronal activity, disrupting the temporal structure and spatial coding. Additionally, the study showed that repeated stress led to a decrease in spinogenesis and spine stability, while acute stress resulted in the stabilization of spines. These findings suggest that loss of structural connectivity mediates the transition from increased activity to impaired temporal organization and spatial information in the dorsal CA1 region under repeated stress exposure.
TRANSLATIONAL PSYCHIATRY
(2022)
