Developmental changes in eye-blink conditioning and neuronal activity in the inferior olive

Neuronal activity was recorded in the dorsal accessory inferior olive in in fant rats during classical conditioning of the eye-blink response. The perc entage and amplitude of eye-blink conditioned responses (CRs) increased as a function of age. The magnitude of the neuronal response to the unconditio ned stimulus (US) decreased with age. There were also age-specific modifica tions of US-elicited inferior olive neuronal activity during paired trials in which a conditioned eye-blink response was performed. The results indica te that the development of the conditioned eye-blink response may depend on dynamic interactions between multiple developmental processes within the e ye-blink circuitry. Differences in the functional maturity of olivocerebell ar pathways may limit the induction of plasticity in the cerebellum and the reby limit the development of eye-blink conditioned responses.