the large conductance ( 250 ps ) ca-activated k+ channel ( bk channel ) is not a major contributor to the afterhyperpolarization in non-innervated skeletal muscle and some nerve cells , because apamin , a neurotoxic component of bee venom , abolishes the afterhyperpolarization but does not block bk channels , and 5 mm extracellular tetraethylammonium ion ( tea ) blocks bk channels but does not reduce the afterhyperpolarization .
C0003521
apamin
C0004920
bee venom