ΔFosB, BDNF, and ΔFosB/BDNF double immunolabeling expressed as labeled cells/mm2 in the ACG (A), PL (B) and IL (C) regions of the mPFC (n = 4-5). All values represent mean ± SEM. *P ≤ 0.05; ** P ≤ 0.01 vs. handled group. D – Representative photomicrograph showing ΔFosB and BDNF single and ΔFosB/BDNF labeling in ACG. ΔFosB profiles are represented by a dark grey nuclear label, and BDNF cells are labeled with a diffuse, purple cytoplasmic stain with an empty nucleus. ΔFosB/BDNF cells contain a dark nuclear ΔFosB label surrounded by diffusely labeled purple cytoplasm. Black arrow: ΔFosB; red arrow: BDNF; blue arrow: ΔFosB/BDNF double-labeling. Scale bar 100 μm.