A calcium-activated, calcium-permeable ion channel in human retinal glial cells: modulation by basic fibroblast growth factor.

A calcium-permeable, voltage-insensitive non-specific cation channel that is activated by cytoplasmic calcium was found in approximately 50% of the cell-attached patches in cultured human retinal glial cells sampled by the patch clamp technique. Spontaneous openings of this channel were infrequent, but increased markedly when glial cells were exposed to basic fibroblast growth factor. Although the role of these cation channels is uncertain, they provide a mechanism to perpetuate a transient rise in cytosolic calcium induced by the release of calcium from intracellular stores.