Effect of histamine on the electric activities of cerebellar Purkinje cell

Abstract

The effect of histamine (HA) on the electric activities of Purkinje cell (PC) is studied on the cerebellum slice. We find that: (1) HA's main effect on PC is excitative (72.9%); there are also a small amount of PC showing inhibitive (10.2%) or no (16.9%) response to HA. (2) Different from the conventional opinion, HA's excitative effect on PC is mutually conducted by H1 and H2 receptors; the antagonist for H1 receptor could weaken HA's excitative effect on PC, while the antagonist for H2 receptor could weaken or even block the excitative effect of HA on PC. (3) PC's reaction to HA is related to its intrinsic discharge frequency; there exists a frequency at which PC is highly sensitive to HA, and well above this frequency PC becomes stable against HA. These results indicate that the histaminergic afferent fibre can adjust PC's electric activities by releasing HA, and thereby influence the global function of the cerebellar cortex; and that just like the $γ$ region of cerebrum, cerebellum may also have some sort of characteristic frequency.