Discussion

Abstract

In this first major set of experiments, we show that, after injury and regeneration of both the facial (motor) and infraorbital (sensory) nerves, noninvasive interventions which ensure a forced use of ipsilateral vibrissae (VS), or which manually stimulate (MS) the whisker pads, improve whisking compared to no treatment; VS followed by MS similarly improves whisking. For all three treatments, functional recovery is associated with reduced polyinnervation of vibrissal muscles. In contrast, regardless of the type of treatment, collateral axonal branching is equally high, whereas synaptic input to facial nucleus motoneurons does not differ from intact animals.