Interactions between the cannabinoid and the serotonergic systems in modulation of pain perception

Abstract

Te aim of our study was to evaluate the efects of cannabinoids and serotonergic system on nociception in intact rats and afer heat stress. Cannabinoid receptor type 1 (CB1) and 5-hydroxytryptamine receptor (5НТ1А) agonists and antagonists have been administered according to diferent experimental designs (alone and in combinations) in intact male Wistar rats, as well in animals subjected to one hour of heat stress. Pain perception has been evaluated by Paw pressure test. Our results pointed out that cannabinoids and the serotonergic system interact in nociception in intact animals as well as afer heat stress. Cannabinoids seemed to have less prominent role in such interaction in intact animals than afer heat stress. Te interplay between the two systems probably involves diferent mechanisms in intact animals and afer heat stress with time-dependent efects. Te interaction between the cannabinoid and the serotonergic systems exerts a modulating rather than mediating efect on h-SIA.