The ionotropic purine type 2X7 receptor (P2X7R) is a non-specific cation channel implicated in sleep regulation and brain cytokine release. Many endogenous rhythms co-vary with sleep including locomotor activity and core body temperature. Further, brain-hypothalamic cytokines and purines play a role in the regulation of these physiological parameters as well as sleep. We hypothesized that these parameters are also affected by the absence of the P2X7 receptor. Herein we determine spontaneous expression of body temperature and locomotor activity in WT and P2X7R knockout (KO) mice and how they are affected by sleep deprivation (SD). We also compare hypothalamic, hippocampal and cortical cytokine and purine-related receptors and enzymes mRNA expressions before and after SD in WT and P2X7RKO mice. Next, in a hypothesis-generating survey of hypothalamic long non-coding (lnc) RNAs, we compare lncRNA expression levels between strains and after SD. During baseline conditions, P2X7RKO mice had attenuated temperature rhythms compared with WT mice, although locomotor activity patterns were similar in both strains. After 6h of SD, body temperature and locomotion were enhanced to a greater extent in P2X7RKO mice than in WT mice during the initial 2-3h after SD. Baseline mRNA levels of cortical TNFα and P2X4R were higher in the KO mice than WT mice. In response to SD, the KO mice failed to increase hypothalamic adenosine deaminase and P2X4R mRNAs. Further, hypothalamic lncRNA expressions varied by strain, and with SD. Current data are consistent with a role for the P2X7R in thermoregulation and lncRNA involvement in purinergic signaling.
- puring signaling
- P2X7R knockout mice
- long non-coding RNA
- adenosine deaminase
- Copyright © 2016, American Journal of Physiology-Regulatory, Integrative and Comparative Physiology