Modulation of neuronal activity of cerebellar fastigial nucleus by locus coeruleus stimulation in the rat

The effects of stimulating locus coeruleus (LC) on neuronal activity of cerebellar fastigii nucleus (FN) was investigated. Stimulation of LC elicited inhibitory, excitatory and biphasic (inhibition-excitation) responses from FN cells. The majority of responsive cells showed an inhibitory response with a latency of less than 10 ms. Injection of a adrenoreceptor antagonists phentolamine (iV) could block the inhibitory response of FN cells to the LC stimulation, but propranolol (IV), a β adrenoreceptor antagonist, could not. These results suggest that LC-cerebellar noradrenergic afferent fibers may be involved in the cerebellar sensorimotor integration process by exerting their modulatory action on the cerebellar nuclear cells’ activities.