In tandem with lesion and stimulation research, electrophysiology studies of increasing sophistication have extended and solidified our understanding of eyeblink conditioning across behavioral, circuitry, and cellular levels. It is now established using peripheral stimuli as well as direct stimulation of nuclei and fibers that Purkinje cells can acquire various types of simple spike modulation within classical conditioning paradigms. Importantly, Hesslow and colleagues have shown in decerebrate ferrets that Purkinje cells with reliable short-latency complex spike responses to the ipsilateral US quite uniformly acquire suppressive simple spike responses with properties that are very similar to behavioral CRs. Additionally, recent work in rabbits has begun drawing confirmative cross-correlations between the kinematic pro- file of eyelid behavior and simple spike activity in awake rabbits