title: Neural network remodeling underlying motor map reorganization induced by rehabilitative training after ischemic stroke.
abstract: Motor map reorganization is believed to be one mechanism underlying rehabilitation-induced functional recovery. Although the ipsilesional secondary motor area has been known to reorganize motor maps and contribute to rehabilitation-induced functional recovery, it is unknown how the secondary motor area is reorganized by rehabilitative training. In the present study, using skilled forelimb reaching tasks, we investigated neural network remodeling in the rat rostral forelimb area (RFA) of the secondary motor area during 4weeks of rehabilitative training. Following photothrombotic stroke in the caudal forelimb area (CFA), rehabilitative training led to task-specific recovery and motor map reorganization in the RFA. A second injury to the RFA resulted in reappearance of motor deficits. Further, when both the CFA and RFA were destroyed simultaneously, rehabilitative training no longer improved task-specific recovery. In neural tracer studies, although rehabilitative training did not alter neural projection to the RFA from other brain areas, rehabilitative training increased neural projection from the RFA to the lower spinal cord, which innervates the muscles in the forelimb. Double retrograde tracer studies revealed that rehabilitative training increased the neurons projecting from the RFA to both the upper cervical cord, which innervates the muscles in the neck, trunk, and part of the proximal forelimb, and the lower cervical cord. These results suggest that neurons projecting to the upper cervical cord provide new connections to the denervated forelimb area of the spinal cord, and these new connections may contribute to rehabilitation-induced task-specific recovery and motor map reorganization in the secondary motor area.
authors.affiliation: Second Department of Physiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan. Electronic address: n-okabe@med.kawasaki-m.ac.jp.
authors.forename: Naohiko
authors.initials: N
authors.lastname: Okabe
authors.affiliation: Second Department of Physiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan; Department of Stroke Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan. Electronic address: shirotaka5377@gmail.com.
authors.forename: Takashi
authors.initials: T
authors.lastname: Shiromoto
authors.affiliation: Second Department of Physiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan. Electronic address: himi@med.kawasaki-m.ac.jp.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Himi
authors.affiliation: Second Department of Physiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan. Electronic address: lufenghome@yahoo.co.jp.
authors.forename: Feng
authors.initials: F
authors.lastname: Lu
authors.affiliation: Second Department of Physiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan. Electronic address: nakamura@bcc.kawasaki-m.ac.jp.
authors.forename: Emi
authors.initials: E
authors.lastname: Maruyama-Nakamura
authors.affiliation: Second Department of Physiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan. Electronic address: naritak@med.kawasaki-m.ac.jp.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Narita
authors.affiliation: Central Research Institute, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan. Electronic address: iwachi@med.kawasaki-m.ac.jp.
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Iwachidou
authors.affiliation: Department of Stroke Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan. Electronic address: yyagita@med.kawasaki-m.ac.jp.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yagita
authors.affiliation: Second Department of Physiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama 701-0192, Japan. Electronic address: mosamu@med.kawasaki-m.ac.jp.
authors.forename: Osamu
authors.initials: O
authors.lastname: Miyamoto
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000473:pathology / Q000503:physiopathology / Q000534:rehabilitation*; D066193:Cervical Cord / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D005552:Forelimb / Q000503:physiopathology; D066128:Gray Matter / Q000473:pathology / Q000503:physiopathology; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009044:Motor Cortex / Q000473:pathology / Q000503:physiopathology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000473:pathology / Q000502:physiology; D011712:Pyramidal Tracts / Q000473:pathology / Q000503:physiopathology; D011897:Random Allocation; D011916:Rats, Inbred F344; D020127:Recovery of Function / Q000502:physiology; D020521:Stroke / Q000473:pathology / Q000503:physiopathology; D000071939:Stroke Rehabilitation
keywords: axonal remodeling; corticospinal tract; motor map reorganization; rehabilitative training; rostral forelimb area; stroke