Role of serotonergic system in thermoregulation in rats

Abstract

The neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) is involved in the regulation of several basic physiological functions such as hormone secretion, sleep-wake cycle, motor control, immune system functioning, nociception, food intake, energy balance and thermoregulation. In addition, 5-HT participates in higher brain functions, such as cognition and emotional states, by modulating synaptic plasticity and neurogenesis. Furthermore, 5-HT has recently captured the spotlight in connection with depression, synthetic narcotic drugs, hot flash, central fatigue, etc. Regarding thermoregulation, many studies have examined the relationship between 5-HT and body temperature (Tb) regulation since the 1960s. Feldberg and Myers, in pioneering experiments, first reported that microinjection of 5-HT into the cerebral ventricles or hypothalamus induced a rise in Tb. Subsequently, research on 5-HT and regulation of Tb continued and topics in recent years include resolving of 5-HT receptor subtypes, such as 5-HT_1A, 5-HT₃, 5-HT₇, and pinpointing a local area or network for thermoregulation. In this short review, I first outline the serotonergic system in the brain, summarize the history of research on 5-HT and thermoregulation, and finally focus on recent research in the 21^st century.