Figure 7.

Inflammation-induced NMDA receptor phosphorylation and the effect of a glial inhibitor. a, Masseter inflammation induced a time-dependent increase in phosphoserine 896 NR1 (P-NR1) in the Vi/Vc. A late (1–7 d after CFA injection) and slight increase in the NR1 protein levels was also seen. Representative immunoblots against anti-P-NR1 and anti-NR1 antibodies are shown on top and the relative P-NR1 and NR1 levels are shown below. *p < 0.05 versus naive. n = 4 per time point. b, Localization of P-NR1 in Vi/Vc neurons 1 d after CFA injection. P-NR1 is shown as green fluorescence (Alexa Fluor 488; top). NeuN is visualized with Cy3 (red; middle). Overlap of left and middle panels reveals cells that exhibit double fluorescence of NeuN (nucleus) and P-NR1 (cytoplasm) in the same neurons (bottom). Examples of double- (arrows) and single- (arrowheads) labeled neurons are indicated. Scale bar, 0.05 mm. c, The effect of PPF on masseter inflammation-induced increase in P-NR1. Propentofylline (10 mg/kg, i.p.) was first injected 20 min before CFA, and the second PPF injection (10 mg/kg) was given 8 h after CFA injection. The Vi/Vc tissues were collected at 1 d after CFA. Saline was injected as a vehicle control for PPF. Compared with noninflamed rats (naive), the P-NR1 immunoreactivity was increased 1 d in rats receiving saline. The PPF treatment attenuated CFA-induced increase in P-NR1 (PPF). **p < 0.01 versus naive. n = 4 per group. Error bars represent SEM.