Daily rhythms of activity and body temperature were measured in golden spiny mice Acomys russatus, acclimated for 2 weeks, at least, to 2 different photoperiod regimes (16L: 8D; 8L: 16D) at a constant ambient temperature of 28°C. Far recording body temperature, VM-FM (Mini-Mitter Co. Inc., Sunriver, OR) transmitters were implanted. For activity measurements, an infrared sensor (Hengstar BL 68 907F, Japan, using a Lodestar PS-303 power supply, Taiwan) mounted on each cage. Both rhythms were also measured in the same individuals exposed to chemical signals released in the urine of A. cahirinus. The results of this study show that both rhythms of A. russatus correlate and respond to changes in photoperiod regimens, as well as to the chemical signals. However, the correlation changes under the 2 photoperiod regimens. Under LD acclimation, a decrease in the correlation is noted, as a response to the addition of chemical signals. Our results suggest that the different responses due to the different light regimens represent 2 seasons in nature, where presumably each season demands a different physiological response.
Bibliographical noteFunding Information:
The authors thank H. Kosik for maintenance of the spiny mice colony. We thank Prof. I. Y. Ashkenazi for statistical advice, as well as anonymous referees for their helpful remarks made on an earlier version of this manuscript. This research was supported by U.S.-Israel Binational Science Foundation, Grant No. 91-00248.
- Body temperature
- Daily rhythms
ASJC Scopus subject areas
- Experimental and Cognitive Psychology
- Behavioral Neuroscience