A GABA (gamma-aminobutyric acid) release-inhibiting agent in the cerebellum and a composition for treating pathological symptoms caused by over-release of GABA in the cerebellum, each comprising a Bestrophin 1 (Best1) channel inhibitor as an active ingredient； a GABA release-promoting agent in the cerebellum and a composition for treating pathological symptoms caused by the deficit of GABA in the cerebellum, each comprising a Best1 channel activator as an active ingredient； and a method for screening a GABA release-regulating agent in the cerebellum, which uses Best1 channel as target, are provided.
