“…Furthermore, receptor-activated Ca: + mobilization from internal stores may in principle induce transmitter release directly. Several presynaptic receptors couple to phospholipase C activation, such as acetylcholine receptors of the muscarinic type (see for instance, Raiteri, 1982;Diamant et al, 1988), 5-HT (Kaczmarek and Levitan, 1987;Delaney et al, 1991), several neuropeptide receptors such as CGRP (Oku et al, 1988), galanin (Martire et al, 1991), vasoactive intestinal polypeptide (see for a review, Chesselet, 1984) and a recently characterized member of glutamate receptors, the metabotrope, tACPD sensitive receptor (Baskys and Malenka, 1991;Calabresi et al, 1992;Rainnie and Shinnick-Gallanger, 1992). As discussed in Section 2, there is already relatively little information as to the potency of presynaptic internal Ca :+ stores.…”