Basal ganglia oscillations: the role of delays and external excitatory nuclei

Basal ganglia are interconnected deep brain structures involved in movement generation. Their oscillations in the beta band (13-30Hz) is known to be linked to Parkinson’s disease motor symptoms. In this paper, we provide conditions under which these oscillations may occur, by explicitly consid-ering the role of the pedunculopontine nucleus (PPN). We analyze the existence of equilibria in the associated firing-rates dynamics, and study their stability by relying on a delayed MIMO frequency analysis. The results are illustrated by simulations.