LSD, DMT, Psilocin, PCP and Ketamine all bind the MT2 receptor extremely strongly. Much more strongly than the 5-HT receptors usually considered as the source of psychedelic effects.
The MT2C (Mel1b) receptor has been demonstrated to inhibit cGMP levels.
[ https://sci-hub.se/https://doi.org/10.1016/s0006-2952(99)00134-3 ]
cGMP is a key mediator of photoreceptor cells. "Recovery of the dark state requires both shut-off of the excitation pathway and synthesis of cGMP to reopen channels.". Given this if cGMP is partially inhibited photoreceptor cells will remain in the illuminated longer and reach higher activation levels. This could explain the increased vividness experienced on psychedelics. With closed eyes random activation of photoreceptors could possibly explain the patterns seen.
[ https://sci-hub.se/http://dx.doi.org/10.2174/138161206778522100 ]
| Ligand | MT2 (kj/mol) | 5-HT1A (kj/mol) | 5-HT2A (kj/mol) | 5-HT2C (kj/mol) | NMDA (kj/mol) |
| LSD | -41.9 | -34.44 | -34.2 | -34.56 | -29.98 |
| DMT | -27.96 | -23.92 | -24.94 | -25.2 | -21.62 |
| Psilocin | -27.14 | -24.01 | -24.04 | -24.58 | -21.16 |
| PCP | -42.75 | -29.33 | -37.5 | -36.53 | -27.1 |
| Ketamine | -34.39 | -27.98 | -29.17 | -30.25 | -22.28 |
The MT2C (Mel1b) receptor has been demonstrated to inhibit cGMP levels.
[ https://sci-hub.se/https://doi.org/10.1016/s0006-2952(99)00134-3 ]
cGMP is a key mediator of photoreceptor cells. "Recovery of the dark state requires both shut-off of the excitation pathway and synthesis of cGMP to reopen channels.". Given this if cGMP is partially inhibited photoreceptor cells will remain in the illuminated longer and reach higher activation levels. This could explain the increased vividness experienced on psychedelics. With closed eyes random activation of photoreceptors could possibly explain the patterns seen.
[ https://sci-hub.se/http://dx.doi.org/10.2174/138161206778522100 ]
