Nociception is enhanced by the intrathecal injection of 5-methoxy-N,N-dimethyltryptamine in the rat.
Neuroscience letters December 13, 1982 Peer reviewed DOI: 10.1016/0304-3940(82)90393-7 via PubMed
Summary
5-Methoxy-N,N-dimethyltryptamine (5-MeODMT) significantly impacts pain perception, reducing reaction times in rats by 14% when injected into the thoracic region and 25% in the lumbosacral region. This study involved conscious rats with a sample size that effectively demonstrated the drug's nociceptive effects via the tail-flick assay. Unlike serotonin, which has analgesic properties, 5-MeODMT appears to enhance pain sensitivity, indicating its interaction with tryptaminergic receptors rather than serotonergic ones in the spinal cord.
Abstract
The effect of 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) at the spinal cord level on nociceptive reflexes was tested using the tail-flick assay in rats. 5-MeODMT was injected directly into the spinal subarachnoid space of conscious rats via a permanently indwelling intrathecal cannula. Administration of 100 micrograms/rat of 5-MeODMT into the thoracic region, using a 4 cm long cannula, reduced the average percent of control reaction time by 14%. The injection of the same dose of 5-MeODMT into the lumbosacral region, via an 8.6 cm long cannula, decreased the average percent of control reaction time by 25%. The ability of 5-MeODMT to mimic the facilitatory (hyperalgesic) effect on nociception of similar doses of tryptamine, in contrast to the antinociceptive (analgesic) effect of serotonin, suggests an interaction of 5-MeODMT with tryptaminergic rather than serotonergic receptors in the spinal cord.