Molecular

What you are looking at

Every receptor here is a real molecule, drawn from the coordinates that crystallography and cryo-electron microscopy have measured: the five human dopamine receptors, D1 to D5, and the twelve serotonin receptors that signal through G proteins, from 5-HT_1A to 5-HT₇. Each sits in a patch of membrane with the outside of the cell above and the cytoplasm below. Pick a family and a receptor in the panel, then follow the tour on the Binding tab: the neurotransmitter arrives, finds the pocket between the helices, the receptor changes shape as it switches on, and the G protein docks beneath it. Drag to turn the molecule, scroll or pinch to zoom, and hover a residue for what it is doing.

The Drugs tab puts other molecules in the same pocket, each from its own structure: the antipsychotics that block D2, the agonists given in Parkinson’s disease, the triptans and ergots of migraine, and LSD and psilocin at 5-HT_2A, with a note on whether each blocks the receptor or mimics its transmitter. Compare lays every subtype of a family side by side in the same state, with the residues of the binding pocket in a table, and About cites every structure. Where no structure of a receptor bound to its own transmitter exists, a stand-in agonist is used and named; the entry path of the ligand and the unresolved loops are drawn as illustration, and the change of shape between resting and active is an interpolation between the two measured states.

The Microanatomy page draws these receptors as schematics beside the transmitters that act on them, and the Region Atlas maps where in the brain each is dense.