Effects of stereotactically induced lesions in the claustrum of rats on motor movements and behavior

The claustrum is a thin, partially irregular cortical structure in the brain which is located underside of the bilateral neocortex on the gray matter, in the subregional of the insula, lateral to the putamen. It receives input from almost all regions of cortex. There are connections with the frontal cortex (motor cortex, prefrontal cortex and cingulate cortex), visual areas of the occipital lobe, the temporal cortex, the parieto-occipital cortex, the posterior parietal cortex, the fronto-parietal operculum, the somatosensorial cortex, the prepyriform olfactory cortex, the entorhinal cortex, the hippocampus, the amygdala, the caudate nucleus. The main function of the claustrum in not clearly known despite these common connections. Especially, there is not too much study done about claustrum and animal behavior. However, close relationship between the claustrum and the behavioral cortical structures is determined. The aim of this study was to investigate the effects of lesion of claustrum on rat behavior. Unilateral and bilateral stereotactic approach was used to make a lesion in the anterior claustrum, with the constant current source which is generating electrical lesion. Rat behavior such as mobilization, freezing, grooming, rearing, eating and drinking, clockwise and counter- clockvwise rotation etc. are recorded and analyzed by automatic behavior recording device and observation of the experimenter. Simultaneously ultrasonic vocalisation of rats were recorded and analyzed with the ultrasonic voice recording programme. Anxiety is investigated with the elevated plus-maze taste. In this study, ventral KL lesions caused significant difference in the spontaneous behaviors like freezing and rearing. In addition to increased anxiety relation occurring behavior variances, on the right KL lesions, significant increase in the duration of drinking behavior, significant decrease in clockwise and counter- clockwise rotation on the complete surgical group are observed. This study showed that the efficiency over the experimental KL lesions and spontaneous behavior and also new studies has to be done over the role of anxiety depression.