The effects of radiation on schedule‐controlled responding and quinpirole‐induced yawning (839.6)

Abstract

A previous report noted that rats receiving head‐only radiation exposure displayed neurobehavioral deficits on the rodent psychomotor vigilance task (rPVT), including changes in accuracy and premature responding. These changes were only apparent in a subset of irradiated rats, such that radiation‐sensitive and radiation‐insensitive groups emerged. Group specific changes in levels of the dopamine D2 receptor and dopamine transporter (DAT) protein were also evident, in addition to differential sensitivity to the rate‐decreasing effects of quinpirole on schedule‐controlled responding.To better understand DA system differences in radiation sensitivity, a cohort of rats was trained to perform the rPVT and then trained on a fixed‐ratio 30 fixed‐interval 2‐min schedule of reinforcement; dopaminergic compounds were administered prior to the FR‐FI session to determine the rate‐altering effects of these drugs in individual subjects. A second cohort of rats was trained to perform the rPVT and was then observed for quinpirole‐induced yawning. Pre‐irradiation rPVT, FR/FI, and yawning data was compared to post‐irradiation data in the same animals, in order to determine how radiation might impact the dopamine system as measured by these behaviors induced by administration of dopaminergic compounds.Grant Funding Source: This work was funded by NSBRI through NASA NCC 9‐58‐PF02602 and 9‐58‐NBPF02802.