Changing patterns of daily rhythmicity across reproductive states in diurnal female Nile grass rats (Arvicanthis niloticus)

PHYSIOLOGY & BEHAVIOR

卷:98

Article

Schrader, Jessica A.¹  Walaszczyk, Erin J.²  Smale, Laura^1,3,4 

[1] Michigan State Univ, Dept Zool, E Lansing, MI 48824 USA

[2] Michigan State Univ, Dept Fisheries & Wildlife, E Lansing, MI 48824 USA

[3] Michigan State Univ, Dept Psychol, E Lansing, MI 48824 USA

[4] Michigan State Univ, Neurosci Program, E Lansing, MI 48824 USA

关键词: Diurnal;    Rhythm;    Grass rat;    Pregnancy;    Lactation;    Locomotor activity;    Body temperature;   

DOI  :  10.1016/j.physbeh.2009.08.012

来源: Elsevier

【 摘 要 】

A suite of changes in circadian rhythms have been described in nocturnal rodents as females go through pregnancy and lactation, but there is no information on such patterns in diurnal species. As the challenges faced by these two groups of animals are somewhat different, we characterized changes in activity and core body temperature (T-b) in female diurnal Nile grass rats (Arvicanthis niloticus) as they went through a series of reproductive states: virgin, pregnant, pregnant and lactating, lactating only, and post-weaning. The phase of neither rhythm varied, but the amplitude did. Females increased their overall levels of daily activity from early to late pregnancy. regardless of whether they were also lactating. The pattern of activity was less rhythmic during early than mid-lactation, in both non-pregnant and pregnant females. as a consequence of a decrease in daytime relative to nighttime activity. The T-b rhythm amplitude dropped from mid-pregnancy through mid-lactation, and there were rises in T-b troughs during the mid-light and mid-dark phases of the day, though pregnancy and lactation affected T-b at these times in somewhat different ways. This study demonstrates that rhythms in diurnal grass rats change during pregnancy and lactation in different ways than those of nocturnal species that have been studied to date and that the effects of pregnancy and lactation are not additive in any simple way. (C) 2009 Elsevier Inc. All rights reserved.

【 授权许可】

Free