. 2020 Sep 18;46(6):1396–1408. doi: 10.1093/schbul/sbaa117

Table 1.

The pharmacology of psychedelics

	Drug Discrimination (DD)	Head-Twitch Response (HTR)	Prepulse Inhibition (PPI)	Exploratory and Investigatory Behavior
Behavioral effect	Rats can be trained to discriminate hallucinogens from vehicle.	Rats and mice treated with hallucinogens express the HTR.	Hallucinogens reduce PPI in rats.	Hallucinogens reduce exploratory and investigatory behavior in rats.
Receptor mechanism for phenylalkylamine hallucinogens (eg, mescaline)	Selective 5-HT_2A receptor antagonists (eg, M100907 and MDL 11,939) block the effect.	Selective 5-HT_2A receptor antagonists (eg, M100907 and MDL 11,939) block the effect.	Selective 5-HT_2A receptor antagonists (eg, M100907 and MDL 11,939) block the effect.	Selective 5-HT_2A receptor antagonists (eg, M100907 and MDL 11,939) block the effect.
Receptor mechanism for indoleamine hallucinogens (eg, LSD and psilocybin)	The mechanism for the DD effects for tryptamine hallucinogens often mediated by both 5-HT_1A and 5-HT_2A receptors. The mechanism for the effect of LSD is time-dependent; at short intervals between injection and testing (eg, 15–30 min), the effect of LSD is blocked by selective 5-HT_2A antagonists; however, if the interval is increased to 90 min then the effect of LSD is blocked by antagonists of D₂-like receptors.	Selective 5-HT_2A receptor antagonists (eg, M100907 and MDL 11,939) block the effect.	Selective 5-HT_2A receptor antagonists (eg, M100907 and MDL 11,939) block the effect.	Indoleamine hallucinogens act through both 5-HT_1A and 5-HT_2A receptor mechanisms.
Sensitivity to lisuride	Lisuride produces hallucinogen-like effects in some DD studies but not in others.	Lisuride does not induce the HTR in rats or mice.	Lisuride reduces PPI in rats but the effect is mediated by D_2/3 receptors rather than the 5-HT_2A receptor.	Lisuride does not produce LSD-like effects on exploratory or investigatory behavior in rats.