Modification of the effects of 5-methoxy-N,N-dimethyltryptamine on exploratory behavior in rats by monoamine oxidase inhibitors.
Psychopharmacology November 1, 2008 Adam L Halberstadt, Mahalah R Buell, Virginia L Masten et al. 46 citations
The psychoactive tea ayahuasca contains DMT, 5-MeO-DMT, and MAO inhibitors harmine and harmaline. In rats, 5-MeO-DMT alone decreased movement and exploration. When combined with a low dose of harmaline, 5-MeO-DMT produced an initial decrease in locomotion followed by a later increase. This shift depended on inhibition of MAO-A, not MAO-B. The late hyperactivity was blocked by a 5-HT2A receptor antagonist, indicating that 5-HT2A receptors mediate this effect, while a 5-HT1A antagonist had no effect. Thus, harmaline alters 5-MeO-DMT's behavioral effects through MAO-A inhibition, and 5-HT2A receptors drive the delayed hyperactivity.