c-Fos immunolabelling was performed using a rabbit polyclonal c-Fos antibody. In brief, sections were quenched in 0.3% hydrogen peroxide (H2O2) for 20 min to remove endogenous peroxidase activity. After serial washing in 0.01 M phosphate- buffered saline (PBS), sections were incubated in phosphate-buffered saline containing rabbit anti c-fos antibody (1:200), 0.3% Triton X, and 0.1% bovine serum albumin (BSA) for 24 h at 4 °C. The incubated sections were then washed and incubated for 90 min in biotinylated goat-anti-rabbit antisera (1:200), followed by washing in 0.01 M PBS. Sections were then incubated in Strep-avidin–biotin–peroxidase complex (ABC) (1:200) for 90 min and then immersed in 0.02% 3,3-diaminobenzidine (DAB) containing 0.01% H2O2 in 0.01 M PBS until a brown reaction product developed.