The influence of social cues on circadian activity rhythm resynchronisation to the light-dark cycle in common marmosets Callithrix jacchus

摘要

The influence of a previously synchronised conspecific of the same sex on the circadian activity rhythm resynchronisation rate to the LD cycle was assessed in five adult male marmosets during a 6h LD cycle delay, followed by a 6h advance, in the absence and presence of a donor. After phase delay with donor, activity onset and offset were resynchronised in fewer days. During the transients, the occurrence of a mid-activity delay, an activity increase in the L-phase and a decrease in the D-phase indicates a faster resynchronisation. After phase advance, activity onset resynchronised promptly and the number of transients for the offset and mid-activity during the transients did not differ. Daily activity increased at phase shifts. Social cues may influence photic synchronisation in marmosets, probably due to direct effects of socially-induced arousal on the circadian pacemaker or by indirect effects, thus increasing photic input or masking.