Editing Inhibitory postsynaptic potential (section)

===Metabotropic receptors===
[[Metabotropic receptors]] are often G-protein-coupled receptors such as [[GABAB receptor|GABA<sub>B</sub> receptors]]. These do not use ion channels in their structure; instead they consist of an extracellular domain that binds to a neurotransmitter and an intracellular domain that binds to [[G-protein]].<ref name=neurobook/> This begins the activation of the G-protein, which then releases itself from the receptor and interacts with ion channels and other proteins to open or close ion channels through intracellular messengers.  They produce slow postsynaptic responses (from milliseconds to minutes) and can be activated in conjunction with ionotropic receptors to create both fast and slow postsynaptic potentials at one particular synapse. Metabotropic GABA receptors, heterodimers of R1 and R2 subunits, use potassium channels instead of chloride.  They can also block calcium ion channels to hyperpolarize postsynaptic cells.