In Vivo Measurement of Pulsatile Release of Neuropeptides and Neurotransmitters in Rhesus Monkeys Using Push–Pull Perfusion

Publisher Summary This chapter discusses the use of push–pull perfusion to measure the in vivo pulsatile release of neuropeptides and neurotransmitters in rhesus monkeys. The direct measurements of the release of neuropeptides, neurotransmitters, and neuromodulators in the stalk-median eminence or portal circulation in animals are essential for neuroendocrine research. To permit insertion of a push–pull cannula into the stalk-median eminence when an experiment takes place, the permanent implantation of a stainless steel chamber onto the skull is necessary. Prior to the initiation of surgery, a sterilized stainless steel needle is placed in the stereotaxic apparatus and the three coordinates of the ear bar zero are recorded. The sterility of the needle is maintained. The needle in the stereotaxic apparatus is positioned on the midline between the cerebral hemispheres at the estimated AP coordinate. For optimal positioning of the push–pull cannula prior to perfusion experiments, the center of the cranial chamber should be placed on the skull directly over the infundibular recess and the top of the chamber should be implanted exactly parallel to the horizontal axis of the stereotaxic frame.