Dopamine acts within the amygdala. Via K+ channels and D2-like receptors, dopamine leads to decreased glutamate secretion. Glutamate activates group 1 metabotropic glutamate receptors, leading to the activation of G-proteins, phospholipase C, cleaving of PIP2 into DAG and IP3, and the opening of intracellular calcium channels. Once open, calcium channels release calcium into amygdala cells, leading to a variety of excitatory effects that cause increased nociception.