Fig. 4. Expression of interleukin-1β (IL-1β) messenger RNA (mRNA) and protein. Reverse-transcription polymerase chain reaction (RT-PCR) ( a ) and immunoblotting ( b ) images for IL-1β are represented for mRNA and protein, respectively, extracted from the hippocampus of a control (no-intervention) rat ( A ), or from rats receiving anesthesia alone tested at 1 ( B1 ), 3 ( B3 ), or 7 ( B7 ) days after anesthesia or animals tested 1 ( C1 ), 3 ( C3 ), or 7 ( C7 ) days after anesthesia and surgery. ( c ) Densitometry data (mean ± SD; n = 7) from the RT-PCR and immunoblotting images compared with that of the housekeeping gene β-actin are plotted as a histogram for each cohort. * P < 0.05, ** P < 0.01 versus control. WB = Western blotting.