Indolethylamine N-Methyltransferase Deletion Impacts Mouse Behavior without Disrupting Endogenous Psychedelic Tryptamine Production.
ACS chemical neuroscience October 15, 2025 Cassandra J Hatzipantelis, Lindsay P Cameron, Min Liu et al.
A new genetic mouse model lacking the enzyme indolethylamine N-methyltransferase (INMT) shows that INMT is not required for the production of endogenous psychedelics, suggesting alternative biosynthetic pathways exist in rodents. INMT knockout mice had no major abnormalities in reproduction or growth but did exhibit altered behaviors across several domains. The study also describes highly sensitive mass spectrometry methods for quantifying endogenous psychedelics in mice. These findings challenge the assumption that INMT is the primary enzyme for endogenous psychedelic production and open new questions about the role of these compounds in health and disease.