CHLORIDE-DEPENDENT PH REGULATION IN CONNECTIVE GLIAL-CELLS OF THE LEECH NERVOUS-SYSTEM

We used double-barreled pH-sensitive microelectrodes to study the mech anisms by which the intracellular pH is regulated in the connective gl ial cells of the medicinal leech. The experiments indicate that a Cl-- and HCO3--dependent mechanism mediates some recovery from intracellul ar alkalosis even in the absence of external Na+. This suggests the pr esence of Na+-independent Cl-/HCO3- exchange in the connective glial m embrane. At alkaline pH(i), this exchange most likely operates in the direction of net acid loading (i.e. HCO3- efflux).