Circadian rhythms differ between selected mouse lines: a model to study the role of vasopressin neurons in the suprachiasmatic nuclei.
Mice selected for differences in nest-building behavior differ in the number of arginine-vasopressin (AVP)-immunoreactive neurons in the suprachiasmatic nuclei (SCN). Although previous efforts to link AVP-immunoreactive neurons in the SCN to clock function have failed, we show that differences in several circadian parameters are associated with differences in the number of AVP-immunoreactive neurons between the selected lines. Although an alternative interpretation is discussed, we hypothesize that these neurons may relay timing information from the circadian pacemaker in the SCN for wheel-running activity. In addition, phase-response curves (PRCs) to 15-min light pulses in constant darkness also differ between the selected lines. However, these differences are not associated with the number of the AVP-immunoreactive neurons in the SCN, but are associated with the level of nest-building behavior. Compared to the Brattleboro rat, in which homozygous rats are deficient for AVP in the entire brain, our system, exhibiting a wide range of variability, has more specific utility for studying the role of the output pathways of the SCN in circadian rhythm control.
Bult
A
A
Department of Biology, Wesleyan University, Middletown, CT 06459-0170.
Hiestand
L
L
Van der Zee
E A
EA
Lynch
C B
CB
D000704:Analysis of Variance; D000818:Animals; D001127:Arginine Vasopressin / Q000502:physiology*; D002940:Circadian Rhythm; D003624:Darkness; D008027:Light; D051379:Mice; D008815:Mice, Inbred Strains / Q000502:physiology*; D009043:Motor Activity; D009474:Neurons / Q000502:physiology*; D051381:Rats; D011910:Rats, Brattleboro / Q000502:physiology; D013493:Suprachiasmatic Nucleus / Q000502:physiology*
D001127:Arginine Vasopressin