FIG. 3. Schematic representation of the coupling of 5-HT2 receptor family to phospholipase C (PLC). The G protein involved has not been identified; it is assumed to be a member of the Gq family. Examples of the physiological consequences of the two bifurcating pathways are given. These have been characterized in Xenopus oocytes expressing the cloned 5-HT2C receptor.