Hideki Hida (Nagoya City University)
“Effect of cortico-rubral tract on the recovery of forelimb function by forced-limb use after intracerebral hemorrhage”
Intensive rehabilitation after stroke has a big influence on the reorganization of the neural circuit and is an effective method to lead the recovery of motor function. It is suggested that the adaptive shift to a new neural circuit participates in the process.
Our group developed an internal capsule (IC) hemorrhage model rat that had a small hemorrhage limited to the bottleneck part of the cortico-spinal tract. Using this IC model rat, we challenge to examine the effect of forced-limb use (FLU) after the hemorrhage on the recovery of motor function with the investigation of the mechanism in adaptive shift to a new circuit of the central nervous system.
We revealed that early FLU after IC hemorrhage by the restriction of the non-paralysis limb (normal side) caused the recovery of skilled forelimb function. We also clarified that cortical map of forelimb area was expanded by intensive FLU accompanied with increased projection of cortico-rubral tract in red nucleus. With the collaboration with Isa’s group, double virus infection was performed to confirm the causality of recovered forelimb function with enhanced cortico-rubral projections.
We will perform more detailed analysis about the FLU effect and the relationship of the cortex – red nucleus pathway. Selective inhibition of this pathway during FLU might clarify the mechanism of FLU effect on adaptive shift to a new neural circuit in the brain.
1. Ishida A, Isa K, Umeda T, Kobayashi K, Kobayashi K, Hida H, Isa T. Causal link between the cortico-rubral pathway and functional recovery through forced impaired limb use in rats with stroke. J Neurosci. 36(2):455-67, 2016
2. Ishida A, Misumi S, Ueda Y, Shimizu S, Jung C-G, Tamakosh K, Ishida I, Hida H. Early constraint-induced movement therapy promotes functional recovery and neuronal plasticity in a subcortical hemorrhage model rat. Behav Brain Res. 284, 158-66, 2015
3. Ueda,Y, Masuda T, Ishida A, Misumi S. Shimizu, Y, Jung C-G, Hida H.Enhanced electrical responsiveness in the cerebral cortex with oral melatonin administration after a small hemorrhage near the internal capsule in rats J Neurosci Res, 92(11): 1499-508, 2014.
4. Ishida A, Tamakoshi K, Hamakawa M, Shimada H, Nakashima H, Masuda T, Hida H, Ishida K. Early onset of forced impaired forelimb use causes recovery of forelimb skilled motor function but no effect on gross sensory-motor function after capsular hemorrhage in rats. Behav Brain Res. 225(1):126-34. 2011