Figure 1. Muscarinic signaling in Xenopus oocytes. A schematic representation of the signaling pathway transducing muscarinic stimulation in oocytes expressing the ml muscarinic receptor. The double line indicates the cell membrane. MCh activates an ml receptor in the membrane. The signal is transduced through a G protein (G) to phospholipase C (PLC). Phospholipase C generates inositoltrisphosphate (IP3) from phosphatidylinositolbisphosphate (PIP2). The IP3releases Calcium2+ from intracellular stores. Finally, this Calcium2+ activates a Calcium2+ dependent Chlorine channel in the membrane, resulting in Chlorine flux. My findings indicate that the pathway from G protein to Chlorine channel is unaffected by halothane.