Abstract:

Abstract:Objective To study the expressions of adenosine and serotonin (5-HT)-related genes in the preoptic anterior hypothalamus (PO/AH) of rats with habenular lesions and with zolpidem treatment and to explore the effect of the habenular nucleus in the sleep-promoting regulation of the PO/AH.Methods Both a rat model with habenular lesion and a hypnotic-treated rat model were established by passing a DC current or by infusing with zolpidem into the stomach and then the rats were divided randomly into habenular sham group,habenular lesion group,vehicle group and zolpidem group.The mRNA levels of adenosine and 5-HT-related genes were examined by RT-PCR in the PO/AH.Results Compared with sham group,only the mRNA expression level of adenosine kinase in the PO/AH had a little increase in habenular lesion group (P> 0.05).However,the expressions of adenosine A1 receptor and 5-HT-related genes (tryptophan hydroxylase and 5-HT2A receptor) were significantly up-regulated in the PO/AH of habenular lesion group (P< 0.05).Compared with vehicle group,the mRNA expression levels of 5-HT-related genes were obviously diminished in the PO/AH of zolpidem-treated rats. Adenosine kinase expression was not statistically decreased (P> 0.05),but adenosine A1 receptor expression just had slight up-regulation in zolpidem group (P> 0.05).Conclusion Habenular nucleus has a regulatory effect on the sleep-promoting PO/AH and its effect is performed by the pathways of adenosine and 5-HT in this process.

Key words: adenosine；habenular nucleus；5-hydroxytryptamine；sleep