Neuron-glia interaction in long-term remodeling of synapses in vivo

Research Director
Junichi Nabekura
Professor, National Institute for Physiological Sciences
Outline
The brain dynamically adapts its function in response to changes in the internal and external environment. Reorganization of neural circuits and synaptic connections between neurons are the key processes that underlie changes in brain function. It has been technically difficult to observe these changes in circuits and synapses in living animals. Therefore, in this study, we utilize two-photon microscopy, a technique that allows imaging of neurons and synapses in living animals over time. We specifically focus on the role of microglia and astrocytes in reorganization of synapses and neural circuits. We aim to reveal the underlying mechanisms by which the brain adapts to its environment and the role of the neuron-glia interactions in this neuronal plasticity.
Joint research groups
Schuichi Koizumi
Professor, University of Yamanashi

Modes of motor information processing in primate cerebro-cerebello-basal ganglia networks

Research Director
Eiji Hoshi
Project Leader, Tokyo Metropolitan Institute of Medical Science
Outline
This study aims to elucidate the neural mechanisms that underlie voluntary motor control driven by networks linking the motor-related areas in the cerebral cortex, cerebellum, and basal ganglia. To address this issue, we adopt three distinct approaches in primates. For structural analyses, we investigate the network architecture surrounding the primary motor cortex using novel anatomical methods, such as transneuronal labeling with rabies virus. For functional analyses, we examine the neuronal activity pattern simultaneously recorded from multiple brain regions in monkeys performing motor tasks, thereby elucidating the functional framework of the brain in which a final motor command is synthesized. For pathophysiological analyses, we investigate the relationship between behavioral changes in motor execution and dysfunction of each brain region or inter-regional connection.
Joint research groups
Atsushi Nambu
Professor, National Institute for Physiological Sciences
Masahiko Takada
Professor, Kyoto University
Kazuto Kobayashi
Professor, Fukushima Medical University

Neurophysiological investigation of mechanisms of cognitive memory network in the cerebral cortex of macaques

Research Director
Yasushi Miyashita
Professor, The University of Tokyo
Outline
Cognitive memory is based on the integrity of the widely distributed network in the brain, and the cognitive memory system provides a flexible basis for mental operations in primates. In this study, we develop novel electrophysiological approaches to examine the network functioning. We aim to reveal the mechanism by which memory neurons (e.g., pair-coding neurons and pair-recall neurons) emerge from the network of temporal and frontal association cortices and are orchestrated for cognitive function by simultaneous recording of multiple single neurons combined with coherence and Granger causality analyses.

Neuronal individuality providing neural circuit formation and cell assembly

Research Director
Takeshi Yagi
Professor, Osaka University
Outline
The brain contains an enormous number of neurons, which are assembled into functional neural networks and also retain individuality. Clustered protocadherin (cPcdh) molecules are candidates for the molecular codes that provide neuronal individuality and specific neural network formation. In this study, we investigate the molecular mechanisms responsible for generating local neural networks and functional cell assembly in the brain by using molecular tools and manipulations to control the expression and function of cPcdh molecules. We aim to reveal the biological basis of sparse parallel-distributed processing of neural information in the brain.
Joint research groups
Katsuei Shibuki
Professor, Niigata University
Masumi Hirabayashi
Associate professor, National Institute for Physiological Sciences