Spike trigger-averaged field potentials recorded from the lateral PML cortex as a result of peripheral stimulation of the vibrissa. 

The cerebellum is one of the most densely populated and regularly organized neural structures in the brain. While the specific function of the cerebellum is still a matter of debate, research has demonstrated that it plays a key role in both motor learning and muscular coordination, as well as displaying some cognitive function.

Because of its regular organization and relatively few types of neural connections, the cerebellar cortex represents an amenable site for neural recording. Previous reports of surface recordings from the cerebellar cortex have been limited to local field potentials recorded with single ball electrodes, eliminating the ability to study temporospatial interactions and giving a very limited picture of cerebellar activity.

We are currently studying cerebellar activity using surface recordings acquired with a subdurally placed flexible multi-electrode array (MultiChannel Systems) in anesthetized rats. We have derived acute recordings of evoked potentials at the cerebellar surface elicited by direct electrical stimulation of both muscles at the periphery (forearm, shoulder, hind limb, and vibrissa) and specific regions of the primary motor cortex (those innervating jaw, forearm, and hind limb). Signals recorded at individual electrode sites displayed characteristic neural components similar to those previously reported for local field potentials recorded in the cerebellar cortex. Stimulation at different cortical sites produced unique and repeatable maps of cerebellar surface activity.