Motor endplate analysis of the denervated and reinnervated orbicularis oculi muscle in the rat

The present study examined the histochemical characteristics of the orbicularis oculi muscle (OOM) in the rat in order to better understand the target muscle of the blink reflex-specifically, the motor endplate distribution and number in the normal, denervated and reinnervated OOM. Assessment of the number of endplates needed to accomplish eye closure would provide critical information in the microsurgical restoration of the blink reflex in facial paralysis. Results demonstrated a 50% increase in the number of endplates of reinnervated rats compared to denervated animals.