Bilateral vestibular deafferentation causes deficits in a 5-choice serial reaction time task in rats

Peripheral lesions of the vestibular system have been associated with spatial memory deficits in animals and humans; however, no study to date has investigated the effects of such lesions on attention. In this study, we used a 5-choice serial reaction time task (5-CSRTT) to determine whether rats with bilateral vestibular deafferentation (BVD) had attention deficits at 5 months post-op. compared to sham controls. We found that BVD rats took longer than sham animals to reach the designated criterion of >70% correct responses (P=0.006), they made significantly fewer correct responses (P=0.005), and significantly more incorrect responses (P=0.000), while showing no difference in omissions and premature responses and a significant decrease in perseverative responses (P=0.03). BVD rats also responded with a significantly shorter response latency, whether their response was correct (P=0.001) or incorrect (P=0.002), and obtained their reward for a correct response more quickly (P=0.000). These results suggest that rats with bilateral vestibular loss exhibit deficits on a 5-CSRTT that cannot be explained by an inability to respond and that their speed of response is altered.