Neurons of the rostral fastigial nucleus are responsive to cardiovascular and respiratory challenges

The rostral fastigial nucleus (rFN) of the cerebellum has been implicated in the neural control of the cardiovascular and respiratory systems. Electrical stimulation and electrolytic lesions of this region produce changes in both cardiovascular and respiratory function. It has been suggested that some of these changes may result from effects on fibers of passage rather than on cell bodies of origin within the rFN. In the present study, extracellular recordings demonstrated a high percentage of units within rFN, as well as in adjacent areas, which responded to induction of acute increases or decreases in arterial blood pressure. Furthermore, units were identified in rFN which responded to respiratory stimuli as well as to changes in blood pressure. Out of the population tested, no units responding to respiratory stimuli were found in areas adjacent to rFN. In addition, a high percentage of neurons tested for response to passive movement also showed changes in firing rate to either cardiovascular or respiratory challenges, or both. Several units were identified (mostly in rFN), whose basal firing pattern was respiratory-related. This suggests the presence of cell bodies of origin within the rFN whose function is related to cardiorespiratory activity.