Selective increases in the density of cerebellar beta-1-adrenergic receptors.

Destruction of noradrenergic neurons by 6-hydroxydopamine or chronic blockade of beta-adrenergic receptors with propranolol increased the density of beta 1-adrenergic receptors two-fold in rat cerebellum but had no effect on the density of beta 2-adrenergic receptors. The results suggest that even through beta 1 receptors comprise only 5-10% of the total number of Beta-adrenergic receptors in the cerebellum they are the receptors specifically innervated by noradrenergic neurons and they may thus be the physiologically important receptors.