NEURONAL-ACTIVITY IN RABBIT NEOSTRIATUM DURING CLASSICAL EYELID CONDITIONING

Extracellular multiple- and single-unit recordings were made from the neostriatum of rabbits during classical eyelid conditioning. Neostriat al neurons processed information regarding the conditioned auditory st imulus (CS) and conditioned eyelid response (CR) as well as the uncond itioned stimulus/response (US/UR). These data are consistent with prev ious reports that neostriatal neurons respond to movement and movement -related sensory stimuli. In most cases, neostriatal neurons increased activity to the US during the early phase of training, but to the CR as training progressed. A close temporal correlation was found between neuronal activity and CR onset with unit discharges typically precedi ng CR onset by 10-50 ms. The activity of some multiple and single unit s was monitored after injection of haloperidol, a neuroleptic and dopa mine antagonist known to disrupt neostriatal function. Interestingly, haloperidol caused a greater disruption of CRs at low-intensity than a t high-intensity CSs, but conditioning-related neuronal activity was d isrupted equally at both intensities. These data are discussed in term s of a possible role for the neostriatum in eyelid conditioning.