A system for delivering mechanical stimulation to the rat whisker pad during facial nerve regeneration

Facial nerve regeneration after transection with immediate neurorrhaphy frequently leads to poor functional recovery in both humans and animal models, and recent advancements in surgical and pharmacologic interventions have had little impact. In contrast, daily passive assistance of whisking movement during the recovery period after facial nerve cut/repair has been shown to dramatically improve facial nerve function in the rodent. Additional studies are needed to understand the mechanisms of this functional enhancement, and to identify optimal stimulation patterns. This report describes a new robotic system for delivering controlled patterns of mechanical whisking assistance after rat facial nerve injury, and provides pilot data of mechanical stimulation treatments that are either preprogrammed (4 or 8 Hz at 65-70 degrees per whisk for 5-20 minutes per day) or yoked to the rat's whisking behavior from the contralateral (intact) side of the face.