Basal levels of phospho-ERK1/2 and -CREB in Caudate-Putamen and Nucleus Accumbens Ad libitum fed and food-restricted rats that were not implanted with i.c.v. cannulas were sacrificed without receiving experimental treatment. Lysates were immunoblotted with anti-phospho ERK1/2 or anti-ERK1/2, and anti-phospho-CREB or anti-CREB antibodies. Following densitometry, intensities of bands corresponding to phosphorylated proteins were divided by intensities of the corresponding total protein bands to correct for small differences in protein loading. Results (mean ± S.E.M.) for caudate-putamen (top) and nucleus accumbens (bottom) are expressed in comparison to the normalized control, which was defined as the ad libitum fed group.