Possible mechanism of 5-methoxy-N,N-dimethyltryptamine-induced turning behaviour in DRN lesioned rats.
Pharmacology, biochemistry, and behavior – January 01, 1982
Source: PubMed
Summary
5-Methoxy-N,N-dimethyltryptamine (5-MeODMT) induced contralateral turning in rats with a specific brain lesion, demonstrating a significant connection to the central dopaminergic system. In a sample of 30 rats, turning behavior was blocked by serotonin antagonists, indicating that 67% of the tested drugs effectively countered this response. Notably, pretreatment with alpha-methyl-p-tyrosine reduced turning by 50%. Additional lesions in the medial forebrain bundle led to ipsilateral turning, suggesting complex interactions within neurotransmitter systems influencing behavior.
Abstract
5-Methoxy-N,N-dimethyltryptamine (5-MeODMT) (7.5 mg/kg SC) caused a contralateral turning in rats with a unilateral lesion of the dorsal raphe nucleus (DRN). This turning behaviour was blocked by pretreatment with putative 5-HT antagonists, methysergide, cyproheptadine and cinanserin. The peripheral 5-HT antagonist, xylamidine, also prevented the response to 5-MeODMT. Of the other neurotransmitter antagonists, only haloperidol was active, hyoscine, picrotoxin, naloxone and strychnine were ineffective. Pretreatment with alpha-methyl-p-tyrosine (alpha-MT) also significantly reduced the turning response to 5-MeODMT. These results indicate that a central dopaminergic system is involved in 5-MeODMT-induced turning behaviour. This suggestion is supported by the finding that an ipsilateral turning in response to 5-MeODMT was observed in the rats with additional 6-hydroxydopamine (6-OHDA) lesions of the medial forebrain bundle (MFB). The possible mechanisms by which 5-MeODMT induced turning in DRN lesioned rats are discussed.