Investigating Cerebrocerebellar Neuronal Interactions in Freely Moving Mice Using Multi-electrode, Multi-site Recordings

The function of any brain structure is to a large extent determined by its interactions with other brain areas or the sensory inputs it receives. The cerebellum has massive reciprocal connections with the cerebral cortex via the thalamus and pontine nuclei. Functional magnetic resonance imaging studies used measures of correlated BOLD signals to demonstrate functional connectivity between virtually all cerebral cortical areas and the cerebellum. Those studies ultimately led to a crucial revision of the long-standing belief of a predominance of sensorimotor areas being connected with the cerebellum. Instead, the results revealed that much of the cerebellar cortical surface is functionally connected with association areas of the cerebral cortex, providing a neurophysiological basis of cerebellar cognitive function. Studies of cerebellar involvement in cognitive function must take those interactions into account by observing neuronal activity in functionally connected areas during relevant behaviors. Here we describe a multi-site extracellular recording approach we developed to simultaneously record neuronal activity in the medial prefrontal cortex, dorsal hippocampus, and cerebellar cortex. Our focus is on the role of coherence of neuronal oscillations as a means of controlling neuronal communication between cerebral cortical areas and the proposed role of the cerebellum in coordinating the task specific modulation of cerebral cortical coherence.