5-Methoxy-N,N-dimethyltryptamine: spinal cord and brainstem mediation of excitatory effects on acoustic startle.
M Davis, D I Astrachan, P M Gendelman, D S Gendelman
Psychopharmacology 1980 DOI: 10.1007/BF00435302 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Rats |
| Interventions | 5-methoxy-N N-dimethyltryptamine (5-MeODMT) |
| Dose | 0.03, 0.06, 0.12, 0.25, 1.0, 2.0, 4.0, and 8.0 mg/kg body weight |
| Topics | 5-MeO-DMT DMT |
| Citations | 39 |
| Key findings | 5-MeODMT increased the acoustic startle reflex in rats in a dose-dependent manner starting at 0.12 mg/kg, an effect that originates in the spinal cord and is blocked by certain serotonin antagonists. |
Abstract
The effects of different doses (0.03, 0.06, 0.12, 0.25, 1.0, 2.0, 4.0, and 8.0 mg/kg body weight) of 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) were tested on the acoustic startle reflex in rats. Beginning at 0.12 mg/kg, 5-MeODMT increased startle monotonically up to the highest dose used. 5-MeODMT still increased startle in acutely decerebrate rats or when infused directly onto the spinal cord. The excitatory effects of a high systemic dose of 5-MeODMT were completely blocked by cinanserin, cyproheptadine, and propranolol, but not by parachlorophenylalanine, alpha-methyl-p-tyrosine, haloperidol, sotalol, or phenoxybenzamine. The results were discussed in terms of a new theory, which suggests that stimulation of serotonin receptors in the spinal cord enhance startle whereas serotonin receptors in the forebrain inhibit startle.