Mapping of different neuropeptides in the lower brainstem of the rat: with special reference to the ventral surface.

A neuropeptide map of beta-endorphin-, vasoactive intestinal peptide-, substance P-, and somatostatin-like reactive neurons and nerve fibers was made by means of immunohistochemistry. Indirect immunofluorescence was carried out in parallel to peroxidase-antiperoxidase reaction using a modified fixation technique. Special interest was directed to the superficial ventral regions of the medulla oblongata where regulative centers for respiration and circulation have been localized. The atlas presented offers a reliable tool for a precise neuromorphological localization of these neuropeptides in pharmacophysiological experiments.