Norepinephrine and synaptic transmission in the cerebellum

Although the presence of norepinephrine (NE) in the mammalian cerebellum was initially controversial, there is now substantial evidence of a role for the NE system in modulating the response properties of individual cerebellar neurons to synaptic inputs rather than transmitting moment-to-moment details of modality specifi c information. As a result of these cellular actions the system is capable of regulating cerebellar circuit functions within the context of ongoing voluntary and refl ex motor activities and in a manner appropriate to the behavioral state of the organism. The evidence for this mode of operation derives from extensive anatomical, physiological and pharmacological investigations over a period of more than 40 years. This chapter summarizes those studies and the development of this concept.