Imaging Core This Core has a confocal microscope and morphometric analysis software, along with multizoom, and fluorescence microscopy capability, and a fully equipped and staffed histology laboratory for histochemical and immunocytochemical labeling. Identification of PPN neurons. A. Two patch clamped PPN cells found to be electrically coupled using electrophysiological criteria. Reconstruction using a confocal microscope revealed several potential points of contact. Calibration bar 40 mm. B. Patch clamped PPN cell (magenta) immunocytochemically labeled for neurobiotin from the recording pipette that was found to have retrobeads (greenish white beads) previously injected into the intralaminar thalamus, indicating that the recorded neuron was a thalamic projection PPN neuron. The same cell was also immunocytochemically labeled as cholinergic (red). Calibration bar 50 mm.