CIRCADIAN LOCOMOTOR ACTIVITY: ROLE OF THE MEDIAL PREOPTIC AREA
Extended recordings of the spontaneous running (locomotor) activity of mammals reveal a robust circadian pattern, i.e., during the daily 24-hour cycle there is a period where the animal is very active and a period of inactivity. This circadian pattern of locomotor activity is under the control of a circadian clock located within the central nervous system in a region known as the suprachiasmatic nucleus (SCN). The timing activity of the clock is synchronized by the environmental light-dark cycle. Destruction of the clock abolishes the circadian rhythm in locomotor activity, which becomes asynchronous. It is not known, however, how the clock organizes the spontaneous locomotor activity into a circadian pattern. Dr. Patrickson will determine the role of the medial preoptic area of the hypothalamus in the circadian organization of locomotor activity by inducing electrolytic lesions within this region. Also, the role of light-dark cycle on the temporal organization of locomotor activity will be determined. The results from this study will provide an insight in to the possible mechanisms involved in the generation of circadian rhythms. In addition, the study of chronobiology in regards to sleep regulation is an enigmatic area of neurobiology that clearly merits further investigation.
