The Importance of Extracellular Potassium for Differentiation of Cerebellar Purkinje Cells in Tissue Cultures

Abstract

Despite the fact that cultures of cerebellar granule cells constitute a popular experimental model, the key functional element of the cerebellum, i.e., Purkinje cells (PC), are rarely studied in tissue culture. There are currently serious methodological disagreements relating to the composition of the medium promoting survival of PC and the development of morphology similar to that of in vivo neurons. The development of cerebellar PC in primary tissue cultures at different potassium concentrations was assessed using combinations of vital calcium imaging and immunohistochemical tissue staining for calbindin-28K as a marker for PC. Studies of rat cerebellum were carried out on culture days 7, 14, and 21. Increases in potassium levels in the medium were found to stimulate PC survival, which promoted increases in body size and the development of the dendritic tree of PC. PC demonstrated the intrinsic spontaneous oscillations in free calcium typical for adult PC.