The contribution of the subthalamic nucleus to executive functions in rat

Subthalamus--Physiology;Executive functions (Neuropsychology);Set (Psychology);Inhibition;Rats--Behavior

Xia, Shuang ; Brown, Verity Joy ; Brown, Verity Joy

University:University of St Andrews

Department:Psychology & Neuroscience (School of)

关键词: Subthalamus--Physiology;    Executive functions (Neuropsychology);    Set (Psychology);    Inhibition;    Rats--Behavior;   

Others  :  https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/5545/ShuangXiaPhDThesis.pdf?sequence=3&isAllowed=y

来源: DR-NTU

【 摘 要 】

Lesions of the subthalamic nucleus (STN) alleviate the cardinal signs ofidiopathic as well as MPTP-induced Parkinson’s disease in primates. For thisreason, the STN is a target for clinical treatment of Parkinson’s disease usingdeep brain stimulation. Despite its small size, the STN plays a vital role in thecortico-basal ganglia-thalamic network. However, the functional features of theSTN have yet to be fully uncovered. The research presented in this thesisexamines the functions of the STN by measuring behavioural changes resultingfrom STN lesions in rats performing executive abilities.In the first experiment, a ‘signal change’ reaction time task was developedand the performance of humans and rats was compared. The main findingswere that although humans and rats used different strategies in the task, thetask did challenge the ability to inhibit unwanted responses. In the second andthird experiments, the effects of bilateral lesions of the STN on performance oftwo variants of the ‘signal change’ task were examined. Rats with the STNlesions were able to inhibit responses when under stimulus control, but wereless able to inhibit responses that were not under stimulus control. In the finalexperiment, the effects of lesions of the STN on inhibitory control in a nonmotor,cognitive domain were examined. Rats with STN lesions were notimpaired on reversal learning, suggesting intact inhibition of previouslyrewarded responses. The rats with STN lesions did show impairments inselective attention which resulted in an inability to form an attentional set.Together, these findings challenge the conventional view that the STNsimply plays a global inhibitory role. Rather, the contribution of the STN toinhibitory control is more complex and neither the motor nor the cognitiveeffects of the lesions are easily explained simply as a failure of inhibition.