Activity–Rest and Body Temperature Rhythms in Mice with Knockout of the Panx1 Gene

Pannexins are a family of three proteins which play an important role in intercellular communications. This study shows that mice with knockout of the Panx1 gene(Panx1–/–) have elevated levels of movement activity and increased proportions of waking, due to decreases in slow-wave sleep, as compared with control animals, as a result of decreases in the adenosine content of the brain. We suggest that these mice may also show impairments to thermoregulation and the daily temperature curve rhythm. To test this suggestion, eight adult male C57BL/6J mice and eight adult male Panx1–/– mice, derived from them, underwent i.p. implantation of autonomous temperature and movement activity sensors. Recordings were made over several months at an environmental temperature of 23 ± 1°C. The results confirmed our previous data indicating higher movement activity in Panx1–/– mice compared with controls. The daily body temperature rhythm in Panx1–/– mice persisted and was no different from that in control animals. The first series of experiments showed an increased tendency to fall into torpor in Panx1–/– mice as compared with controls. However, no onset of torpor occurred in the next series, using a further four pairs of animals. Thus, the role of the Panx1 gene in the diurnal activity-rest rhythm was confirmed, while its role in the temperature rhythm and thermoregulatory reactions remains unclear and requires further study.