Adolescent Changes in Dopamine D1 Receptor Expression in Orbitofrontal Cortex and Piriform Cortex Accompany an Associative Learning Deficit
Figure 4
Dopamine D1 receptor protein expression increases in adolescence. A)
Subregions of the OFC (LO and VLO) and piriform cortex (APCd and APCv) sampled to determine the number of D1 receptor-immunopositive cells at each age. Drawings of the right hemisphere shown, adapted from Paxinos and Watson (2007). Uniform sampling boxes were placed randomly within each area and all immunopositive cells were counted. All counts were performed by experimenters blind to the age and identity of the sections. B) Average number of D1-immunopositive cells counted in each sampled region for juvenile (white bars), adolescent (gray bars) and adult rats (black bars). Within each subregion, a significant increase in the number of immunolabeled cells was found in adolescence compared with either juveniles or adults (*p<0.001). C) High-power photomicrographs of sampled regions in the OFC of juvenile, adolescent and adult rats. Scale bar = 100 µm, applies to all photomicrographs in C.