[7] The receptor functions as an autoreceptor for glutamate, that upon activation, inhibits the emptying of vesicular contents at the presynaptic terminal of glutamatergic neurons.

Group II and III receptors are linked to the inhibition of the cyclic AMP cascade but differ in their agonist selectivities.

The development of subtype-2-selective positive allosteric modulators (PAMs) experienced steady advance in recent years.

[38][39] Lisuride acts preferentially or exclusively on the non-heteromerized 5HT2A receptors, which are not capable of inducing psychedelic effects.

It is still to be clarified whether the Rabies virus glycoprotein can act as a PAM or NAM and in such a way affect the function of the receptor.