Figure 5: Double immunofluorescence laser scanning confocal microscopy images demonstrating the location of nicotine (NIC), and nicotine pyrrolidine methiodide (NIC-PM) induced c-Fos immunoreactive (IR) neurons with respect to tyrosine hydroxylase (TH) IR DA11 cells in posterior hypothalamus. Panels A–C: Control data demonstrating effects of acute intraperitoneal injection of physiological saline (PS) on c-Fos activation of TH IR DA11 cells. Panels D-F and G-I: NIC and NIC-PM data respectively, showing c-Fos IR cells (D, G), TH IR cells (E, H) and merge images of c-Fos with TH IR DA11 cells (F, I). Arrows point to areas magnified in photomicrographs.