Figure 4.

Leptin and IL-1β regulate tyrosine hydroxylase expression in NAc. A, Expression of TH in the NAc was upregulated in S/MS and CFA/MS rats exposed to morphine conditioning; β-Actin: loading control; **p < 0.01 compared with S/V. B, TH immunoreactivity was expressed in the NAc. Scale bar, 50 μm. C, Intra-NAc microinjection of a leptin antagonist (LA) (4 μg) or an IL-1β antagonist (IL-1 ra, 100 μg), once daily for 5 d, prevented Th upregulation in LA/MS and IL-1 ra/MS; **p < 0.01 compared with Veh/Veh. Data are shown as mean + SD.