Effect of the natural fragrance “cedrol” on dopamine metabolism in the lateral hypothalamic area of restrained rats: A microdialysis study

It has been reported that cedrol, a natural crystalline substance derived from cedar wood oil, has sedative effects on behavioral and autonomic activities in animals. In the present study, the effect of cedrol on dopamine (DA) metabolism was investigated in the lateral hypothalamic area (LHA) of restrained rats using an in vivo microdialysis technique. Immobilization stress increased DA release in the LHA with concomitantly large increases in 3,4 hydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels, indicating that it activates the dopaminergic system in the brain. When the rats were exposed to cedrol, DA release was unchanged during and after immobilization stress compared with the basal level. The DOPAC and HVA levels showed only small increases during immobilization stress, and almost returned to basal levels after immobilization stress. The present results indicate that cedrol inhibits an increase in dopamine metabolism induced by immobilization stress, and suggest that the sedative effects of cedrol on behavioral and autonomic activities are partly due to the inhibition of dopaminergic neurotransmission and the modulation of LHA neuron activity by DA.