Figure 3.

Selective overexpression of MRAP2 in MC4R expressing neurons in the PVN affects neuronal activation in female mice which is further increased with MTII administration. (A and B) Representative hypothalamic sections from a female Mc4r-cre^PVN-GFP (A) and a female Mc4r-cre^PVN-MRAP2 mouse both injected IP with saline (B) immunostained for cfos (red) in the hypothalamic paraventricular nucleus (PVN). (C and D) Representative hypothalamic PVN sections immunostained for cfos from a Mc4r-cre^PVN-GFP (C) and a Mc4r-cre^PVN-MRAP2 mouse (D) following IP injection with MTII. (E) Quantification of cfos expression in the PVN of Mc4r-cre^PVN-GFP (n = 5) and Mc4r-cre^PVN-MRAP2 female mice (n = 6) post IP saline and cfos expression in the PVN of Mc4r-cre^PVN-GFP (n = 4) and Mc4r-cre^PVN-MRAP2 female mice (n = 4) injected with MTII. (F) Graph showing no differences in feeding responses (food intake over 24 h) after peripheral injection of MTII in female Mc4r-cre^PVN-GFP (n = 4) and Mc4r-cre^PVN-MRAP2 mice (n = 4) three months after the PVN viral injections. A significant difference is noted between saline treated and MTII treated animals in both groups. 3v = third ventricle; PVN = paraventricular nucleus of the hypothalamus. Bar scale in A–D represents 100 μm. All data are presented as mean ± SEM. **P < 0.01 compared to Mc4r-cre^PVN-GFP mice.