Neuron differentiation-related genes are up-regulated in the hypothalamus of odorant-inhaling rats subjected to acute restraint stress.

ABSTRACT

To elucidate some physiopsychological effects of a pleasant odor, we analyzed gene expression profiles in the hypothalamus of rats which, under a restraint-stressed condition, inhaled (R)-(-)-linalool. Consequently, 697 probe sets showed significant expression changes in the odorant-inhaling rats subjected to 2 h of restraint stress (false discovery rate < 0.05). We observed up-regulation of 594 among them, including genes related to neuron differentiation and transcriptional regulatory factors. Another important result was that inhalation of (R)-(-)-linalool returned the expression of 49 restraint-regulated genes to a normal condition. In contrast, the inhalation also further up-regulated the expression of 16 restraint-up-regulated genes that included those encoding heat shock proteins as factors to induce some biological responses against stresses. In the present study we thus found the substantial example that, in the hypothalamus involved in feeding behaviors, an inhaled pleasant odor acts to regulate the gene expression related to the functions of neuronal developments to cope with stresses.