High frequency organization and synchrony of activity in the Purkinje cell layer of the cerebellum
Clement Lena1, Camille de Solages1, German Szapiro1, Nicolas Brunel2, Vincent Hakim3, Philippe Isope1, Charly Rousseau1 and Boris Barbour1
1Laboratoire de Neurobiologie UMR 8544, Ecole Normale Superieure, France, 2Laboratoire de Neurophysique et Physiologie, UMR 8119, Universite Rene Descartes, France, 3Laboratoire de Physique Statistique UMR 8550, Ecole Normale Superieure, France

The cerebellum controls complex, coordinated and rapid movements, a function requiring precise timing abilities. However, the network mechanisms that underlie the temporal organization of activity in the cerebellum are largely unexplored, because in vivo recordings have usually targeted single units. Here, we use tetrode and multi-site recordings to demonstrate that Purkinje cell activity is synchronized by a high-frequency (~200 Hz) population oscillation. We combine pharmacological experiments and modeling to show how the recurrent inhibitory connections between Purkinje cells are sufficient to generate these oscillations. A key feature of these oscillations is a fixed population frequency that is independent of the firing rates of the individual cells. Convergence in the deep cerebellar nuclei of Purkinje cell activity, synchronized by these oscillations, likely organizes temporally the cerebellar output.