Developmental regulation of voltage-gated K+ channel and GABAA receptor expression in Bergmann glial cells

摘要: Bergmann glial cells are closely associated with neurons: during development they provide guiding structures for migrating granule and in the adult cerebellum display intimate interactions Purkinje cells. In this study, we have addressed question of whether such changes neuronal-glial accompanied by variations membrane properties We used a mouse slice preparation to study currents at various stages situ using patch-clamp technique. The distinct morphology was revealed Lucifer yellow injections recording. While mice postnatal day 20 (P20) P30 thick processes arborized, irregularly shaped leaf-like appendages, from younger (P5-P7) thinner smoother. This morphological maturation is variation voltage-gated currents. P5 P7, delayed outward- inward-rectifying K+ were recorded, while older characterized by, large, voltage- time-independent addition, application GABA induces two effects, rapid activation Cl- conductance longer-lasting decrease (resting) conductance. Both effects mediated benzodiazepine-insensitive GABAA receptors. Responses P5-P7 large as compared small or even undetectable responses P20-P30 These receptors immunohistochemically rat brain sections five subunit-specific antibodies. exhibit but transient immunoreactivity receptor alpha 2-, 3-, delta-subunits. Staining maximal between P7 P10 decreases gradually thereafter. contrast, antibodies 1- beta 2,3-subunits fail decorate cells, although yield prominent staining both cell expression suggest transition functional states