120918 Schmidt

The Bernstein Center Freiburg

Bernstein Seminar

Robert Schmidt

Department of Psychology
University of Michigan Ann Arbor, USA

Canceling actions involves a race
between basal ganglia pathways

Abstract:
Salient cues can prompt the rapid interruption of planned movements. It has been proposed that such action cancellation involves a specific basal ganglia pathway through the subthalamic nucleus (STN).
Here we test this idea by comparing activity in multiple rat basal ganglia structures during stop-signal task performance. STN neurons showed low latency responses to Stop cues, irrespective of whether actions were successfully canceled or not. By contrast, neurons downstream in the substantia nigra pars reticulata (SNr) responded to Stop cues only when actions were successfully suppressed. Recordings and simulations together indicate that this sensorimotor gating arises from the relative timing of two distinct inputs to SNr: cue-related excitation from STN and movement-related inhibition from striatum. Our results support race models of action cancellation, with successful stopping requiring Stop cue information to be transmitted from STN to SNr before increased striatal input creates a point of no return.

Host: Arvind Kumar