A central role for norepinephrine in the modulation of cerebellar learning tasks.

Norepinephrine (NE) is a central nervous system neuromodulator that enhances the actions of other neurotransmitters such as gamma-aminobutyric acid and glutamate. Based on the Marr-Albus theories, Gilbert suggested that NE influences consolidation of cerebellar learning. NE depletion or blockade of postsynaptic noradrenergic receptors decreases the rate of learning in several cerebellar-dependent learning tasks. Loss of cerebellar beta-adrenergic receptor function correlates with a loss of function in related learning tasks. Interventions that improve beta-adrenergic receptor function also improve performance in cerebellum-dependent learning tasks. Thus, the authors propose that NE has a central role in the modulation of learning within the cerebellum.