A composition comprising a novel Ca2-activated [ATP]-sensitive nonspecific cation (NCca ATP) channel is described. The channel is found in mammalian neural cells and exhibits a different sensitivity to block by various adenine nucleotides and is activated by submicromolar [Ca]i. The NCCa-ATP channel is activated under conditions of ATP depletion which causes severe cell depolarization followed by cell swelling- The NCCa-ATP channel is regulated by a sulfonylurea receptor and is inhibited by sulf...