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.
Neuropharmacology
January 1, 2011
Maarten Van den Buuse, Emma Ruimschotel, Sally Martin et al.
37 citations
Mice lacking the serotonin-1A (5-HT(1A)) receptor showed enhanced hyperactivity in response to amphetamine, a model of the hyperdopaminergic state linked to psychosis. The response to MK-801, which models NMDA receptor hypoactivity, was unchanged. The effect of the hallucinogen 5-MeO-DMT was markedly reduced in the knockout mice. No changes were seen in sensory gating deficits induced by apomorphine, nor in the density of dopamine transporters or D1/D2 receptors. These results suggest that 5-HT(1A) receptors play a role in hallucinations and modulating dopamine activity, extending insight into their possible involvement in schizophrenia.
Pharmacology, biochemistry, and behavior
September 1, 2009
Vikas Duvvuri, Victoria B Risbrough, Walter H Kaye et al.
7 citations
A translational model of anorexia nervosa (AN) was tested using a hyponeophagia assay in mice, where food-deprived animals showed increased latency to begin feeding in a novel, anxiety-provoking environment. The non-selective serotonin agonist 5-MeODMT potentiated feeding inhibition beyond that caused by the environment alone, indicating a drug-by-environment interaction. Blocking the 5-HT(1A) receptor with WAY100635 reversed this effect, supporting a necessary role for 5-HT(1A) receptor activation in feeding inhibition. The findings suggest a mechanistic link between elevated 5-HT(1A) receptor activity and restricting-type AN, with implications for the interplay between anxiety and appetite suppression.