Figure 1.

Confocal projections of Y₁R neurons in the ARH of OVX (A), EB (B), NPY (C), CNNY_27–36 (D), EB plus progesterone (EB+P; E), or EB+P+NPY-treated (F) rats. Large arrowheads indicate Y₁R immunoreactivity associated with the plasma membrane (A, D, E), suggesting that these receptors have not been activated. Small arrows indicate the immunoreactivity was not associated with the plasma membrane, suggesting an internalization of Y₁R (B, C, F). Please note that OVX females showed Y₁R immunoreactivity associated with the membrane and in the cytoplasm.