Fig. 4.

Diurnal variation in the relative amount of interleukin-1β (IL1) mRNA and P2X7 receptor mRNA and protein in the hypothalamus and somatosensory cortex. A: Western blot analyses of somatosensory cortex samples showed variation of P2X7 receptor protein levels at 1500 (3 h after light onset) or 0300 (3 h after dark onset). No differences in time of day were observed in the standard, β-actin. B: time course of P2X7 receptor mRNA and protein (▴) and IL1 mRNA (●). The levels of P2X7 receptor protein (somatosensory cortex) and mRNA [(hypothalamus (□) and somatosensory cortex (▼)] were greater during the light period than during the dark period (black horizontal bar indicates dark period). Expression of protein levels was normalized to β-actin levels. *Statistical significance (P < 0.05) from values obtained at 2100; +significant differences from dark onset; #significant differences from values obtained 12 h before.