Abstract # 65:

Scheduled for Thursday, August 17, 2006 07:00 PM-09:00 PM: Session 8 (Regency West 1/3 ) Poster Presentation

Circadian activity patterning in adolescent male cynomolgus monkeys

P. Pierre and A. J. Bennett
Wake Forest University Health Sciences, Winston-Salem, NC, USA
     Adolescence is a developmental period characterized by biobehavioral changes, including changes in the circadian organization of behavioral activity. Profound changes in sleep and activity patterning have been observed in human adolescents. In the study reported here we characterized developmental change through the juvenile to adolescent period in multiple physiological and behavioral measures in male, cynomolgus (Macaca fascicularis) monkeys. We hypothesized that the changes observed in activity patterning in these monkeys would parallel the developmental change observed in human adolescents; namely, lengthening of sleep onset, delayed waking time, and decreased sleep quality. Wrist-watch actimetry was used to record the circadian activity patterning of thirteen, male cynomolgus monkeys at two time points (30 vs 50 months of age) during the transition to adolescence. Behavioral activity was recorded for 9 consecutive 24hr periods at each timepoint. Within-subjects comparisons between activity at 30 vs 50 months of age showed that latency to sleep increased with age (F(1,23)=27.68; p <0.01). The onset to initial activity at the beginning of the daily light period, or rise time, was delayed at the 50 month timepoint (F(1,23)= 70.01, p<0.01). Our results parallel those found in human studies. These data illustrate the usefulness of circadian measures of activity as significant behavioral indicators of developmental changes surrounding the onset of adolescence in primates. Supported by NIAAA grant #AA013995.