Photic and nonphotic circadian phase resetting in a diurnal primate, the common marmoset

J. David Glass, Suzette D. Tardif, Robert Clements, N. Mrosovsky

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


Despite the considerable literature on circadian entrainment, there is little information on this subject in diurnal mammals. Contributing to this lack of understanding is the problem of separating photic from nonphotic (behavioral) phase-resetting events in diurnal species. In the present study, photic phase resetting was obtained in diurnal common marmosets held under constant dim light (DimDim; <0.5 lx) by using a 20-s pulse of bright light to minimize time available for behavioral arousal. This stimulus elicited phase advances at circadian time (CT) 18-22 and phase delays at CT9-12. Daily presentation of these 20-s pulses produced entrainment with a phase angle of ∼11 h (0 h = activity onset). Nonphotic phase resetting was obtained under DimDim with the use of a 1-h-induced activity pulse, consisting of intermittent cage agitation and water sprinkling, delivered in total darkness to minimize photic effects. This stimulus caused phase delays at CT20-24, and entrainment to a scheduled daily regimen of these pulses occurred with a phase angle of ∼0 h. These results indicate that photic and nonphotic phase-response curves (PRCs) of marmosets are similar to those of nocturnal rodents and that nonphotic PRCs are keyed to the phase of the suprachiasmatic nucleus pacemaker, not to the phase of the activity-rest cycle.

Original languageEnglish (US)
Pages (from-to)R191-R197
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Issue number1 49-1
StatePublished - Jan 2001


  • Arousal
  • Circadian rhythm
  • Light
  • Nonhuman primate

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)


Dive into the research topics of 'Photic and nonphotic circadian phase resetting in a diurnal primate, the common marmoset'. Together they form a unique fingerprint.

Cite this