Representative images of oxytocin (green), CRF (red), and Hoechst (blue) positive cells were taken using a Zeiss LSM 700 microscope at 63× magnification (Zeiss, Oberkochen, Germany). Tat(−)/morphine (B), Tat(+)/saline (C), and Tat(+)/morphine (D) PVN tissue sections had less oxytocin immunoreactive-cells compared to Tat(−)/Saline (A) control sections. Scale bar = 20 μm.