title: Contribution of neuronal and glial circuit in intact hemisphere for functional remodeling after focal ischemia.
abstract: The number of people who suffer from disabilities such as aphasia and/or paralysis after a focal brain stroke has not markedly decreased even in countries with established medical care systems. Functions such as speech can be lost following a stroke; however, such functions can sometimes be recovered. In this review, we focus on functional compensation that was achieved by the intact region contralateral to the stroke region. Using a mice stroke model, we used in vivo imaging techniques in combination with conventional electrophysiology and behavior tests, which showed that functional recovery was achieved through the specific synaptic (neuronal circuit) remodeling at the region contralateral to the focal stroke region 1 week after the stroke. During this period, astrocytes play a critical role in reducing the accumulation of synaptically released glutamate in the extracellular space, which would otherwise cause excitotoxicity. These findings indicate that the hemisphere that was intact after a stroke can potentially achieve bilateral functions even in adults when proper remodeling of neuronal circuits occurs. Activating the intact hemisphere may become a new therapeutic strategy for stroke patients.
authors.affiliation: Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan. Electronic address: takatsur@gunma-u.ac.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Takatsuru
authors.affiliation: Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; CREST, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan; The Graduate University for Advanced Studies, Hayama, Kanagawa 240-0193, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Nabekura
authors.affiliation: Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Koibuchi
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000503:physiopathology*; D054022:Cerebrum / Q000503:physiopathology*; D051379:Mice; D009457:Neuroglia / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology; D020521:Stroke / Q000503:physiopathology*
keywords: Astrocyte; In vivo imaging; Stroke; Synaptic remodeling