Hoffmann reflex in a rat bipedal walking model.

The rat bipedal walking model (RBWM) refers to rats that acquired anatomical and functional characteristics for bipedal walking after the completion of a long-term motor training program. We recorded the Hoffmann reflex (H-reflex) of the forelimb and hindlimb in RBWM and control (not trained, normal) rats to evaluate the effects of bipedal walking on central nervous system (CNS) activity. The H-reflex recorded from the hindlimbs of the RBWM was significantly inhibited compared with that in the control. Furthermore, the inhibition of the H-reflex recorded from both forelimbs and hindlimbs by paired pulse stimulation tended to be enhanced in RBWM. These results indicate that bipedal walking or bipedal walking training cause functional changes in spinal reflex pathways in the CNS.