function of voltage-gated calcium channels, leading to inhibition of neurotransmitter release, and also appear to have more direct effects on vesicle fusion (Dolphin 2003; Elmslie 2003; Miller 1998; Wu and Saggau 1994). The Gq-like α subunits activate protein and lipid signaling pathways that activate ion channels that excite neurons, inhibit potassium channels, and increase neurotransmitter release. Thus, activation of the Gq-subclass generally has a net excitatory effect on neuronal activity and synaptic transmission. The proximal effects of Gs-like G protein activation are not always clear. The α subunit of these G proteins stimulates AC/cAMP formation which can enhance synaptic transmission and inhibits some potassium channels. The effects on ion channel function of the different G proteins are outlined in detail in previous review articles (Dolphin 2003; Elmslie 2003; Wickman and Clapham 1995).
