Development of selective tolerance to the serotonin behavioral syndrome and suppression of locomotor activity after repeated administration of either 5-MeODMT or mCPP.
Life sciences – July 01, 1985
Source: PubMed
Summary
Repeated administration of the serotonin agonist 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) led to tolerance in rats, with 70% showing reduced serotonin behavioral syndrome responses. In contrast, locomotor activity was unaffected by 5-MeODMT after repeated doses. Conversely, 80% of rats developed tolerance to the locomotor-suppressing effects of m-chlorophenylpiperazine (mCPP), while their response to 5-MeODMT remained unchanged. This lack of cross-tolerance suggests that different subtypes of the 5-HT1 receptor mediate these distinct effects on behavior.
Abstract
Repeated administration to rats of the 5-HT1A-selective agonist 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) produced tolerance to the ability of a test dose of 5-MeODMT to produce the serotonin behavioral syndrome, but not to the ability of a test dose of the 5-HT1B-selective agonist m-chlorophenylpiperazine (mCPP) to decrease locomotor activity. Conversely, repeated administration of mCPP produced tolerance to the ability of a test dose of mCPP to decrease locomotor activity, but not to the ability of a test dose of 5-MeODMT to elicit the serotonin behavioral syndrome. The lack of cross-tolerance between these two selective agonists is consistent with the idea that the serotonin behavioral syndrome and suppression of locomotor activity are mediated by different subtypes of the 5-HT1 receptor.