TY - JOUR T1 - Thermoregulation-Independent Regulation of Sleep by Serotonin Revealed in Mice Defective in Serotonin Synthesis JF - Molecular Pharmacology JO - Mol Pharmacol SP - 657 LP - 664 DO - 10.1124/mol.117.111229 VL - 93 IS - 6 AU - Xian Zhang AU - Hongming Yan AU - Yanjia Luo AU - Zili Huang AU - Yi Rao Y1 - 2018/06/01 UR - http://molpharm.aspetjournals.org/content/93/6/657.abstract N2 - A role for 5-hydroxytryptamine (5-HT) or serotonin in sleep has been known for decades but was challenged by recent papers that concluded that the apparent sleep phenotype was secondary to defective thermoregulation. Those studies used mice lacking serotonergic neurons resulting from the loss of function mutations in the gene encoding the LIM homeobox transcription factor 1 (Lmx1b). Here we show that, while Lmx1b mutants failed to keep the physiologic body temperature, they exhibited more activities at the room and elevated temperatures. More importantly, we used mice deficient in the gene encoding tryptophan hydroxylase 2 (Tph2), which could not synthesize 5-HT in the brain. Tph2 mutants were capable of thermoregulation and keeping physiologic body temperature when the environmental temperature was reduced and exhibited significantly more activities at both the room and elevated temperatures. Electroencephalographic (EEG) recording also showed decreased sleep in Tph2-deficient mice. Our results indicate that 5-HT is important for sleep regulation but not thermoregulation. ER -