Bi‐hemispheric contribution to functional motor recovery of the affected forelimb following focal ischemic brain injury in rats

• DOI: 10.1111/j.1460-9568.2005.03899.x
• Publication Date: 2005-03-09T13:21:03Z
• Authors: Jeff Biernaskie; Aleksandra Szymanska; Victoria Windle; Dale Corbett
• Keywords: Forelimb

Abstract In many recovering hemiparetic stroke patients, movement of the affected limb elicits ipsilateral activation sensorimotor areas within undamaged hemisphere, which is not observed in control subjects. Following middle cerebral artery occlusion, rats received intensive enriched‐rehabilitation (ER) impaired forelimb for 4 weeks. Weekly assessments on a skilled reaching test demonstrated significant improvement ischemic animals over weeks ER ( P < 0.05). We hypothesized that if motor cortex contributed to improved function, then inhibition neural activity this region should reinstate (at least some of) initial impairment. After 3 and ER, microinjection lidocaine hydrochloride into were re‐assessed ability. The behavioral effect challenge was dependent size infarct: with large infarcts rendered unable retrieve any food pellets had great difficulty even contacting pellet forepaw. Small‐infarct only moderately (25% reduction success) by lidocaine, an similar animals. Qualitative recovered after rehabilitation revealed impairments lift, advance aim exacerbated 0.05) following lidocaine‐inactivation infarcts. small infarcts, advance. Thus, recruitment hemisphere may depend functional integrity remaining system. These data suggest that, rat, (ipsilateral) system contribute compensatory recovery forelimb.