Classical discrimination conditioning of the rabbit's eyelid response using pontine stimulation as a conditioned...

Classical discrimination conditioning of the nictitating membrane/eyelid response was performed on seven rabbits using stimulation of the pontine nuclei or middle cerebellar peduncle as the conditioned stimulus (CS) and an air puff as the unconditioned stimulus (US). The rabbits learned to discriminate between a CS paired with a US and delivered to one pontine nucleus (the CS+) and a CS presented alone and delivered to the contralateral pontine nucleus (the CS-). Subsequent reversal of the discrimination was also achieved when the CS+ and CS- stimulation sites were interchanged. The results are interpreted as support for the idea that essential plasticity for classical eyelid conditioning occurs efferent to the pontine nuclei, possibly in regions of the cerebellum.