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Accueil du site > Séminaires LNC > séminaires à venir (upcoming seminars)

Julien Bastin

Functional role of the subthalamic nucleus : insights from invasive human recordings

Subthalamic nucleus (STN) is a basal ganglia structure that is suggested to be critically involved in the pathophysiology of obsessive compulsive disorders (OCD). STN shows abnormal burst activity at rest in patients with OCD, and is a preferential target for deep brain stimulation (Mallet et al. 2008). However, very little is known about human STN in non dopamine-depleted conditions, such as in OCD. In my talk, I will present results from a study that investigates non-motor functions supported by the STN in patients with OCD. First, we recorded single neurons of STN in severe OCD patients performing a stop-signal task during the neurosurgery. We found that different neuronal populations increased their firing rate either during motor execution, inhibitory control, or after behavioural errors. Secondly, we performed post-operative local field potentials recordings few days after the surgery, and we found a similar STN functional segregation in the beta band. As expected from previous studies in patients with Parkinson’s disease, we found that beta band activity decreased during movement execution. Conversely, beta activity exhibited a selective increase, only after successful response inhibition. Taken together, these studies demonstrate that the STN may not only support signals mediating action selection (i.e., contributing to the execution and inhibition of actions), but may also contribute to the monitoring of action consequences. We propose that the STN is a hub in the brain’s executive control system where multiple cognitive functions would be integrated.