Dr. Fukuhara's research focuses on circadian rhythm generation and organization in mammals. Most of the organisms living on earth show about 24 hour (circadian) rhythms that are endogenously controlled by biological clocks. In mammals, these rhythms are generated by the circadian clock localized to the suprachiasmatic nucleus (SCN) of the hypothalamus. Recent studies have shown that mammals possess multiple circadian oscillators, and the mammalian circadian system is hierarchically organized in that the SCN (the master circadian pacemaker) controls the peripheral oscillators in order to coordinate the physiological events in an entire body. We investigate the mechanisms by which the SCN controls peripheral oscillators, and roles of peripheral circadian oscillators in regulating physiological events in the mammalian pineal gland, liver, and heart.

Our approaches are monitoring and manipulating circadian clock genes expression in the primary cultures using real time quantitative PCR, siRNA, semi-quantitative in situ hybridization, and DNA microarray techniques. Besides biological importance and interests, ours research is applicable to jet lag and shift work problems in humans, since they are related to de-synchronization among the central oscillators in the SCN and peripheral oscillators.