[Localization of leu enkephalin in animal and human brain stem]

At investigating brains of humans, rabbits and pigeons by means of the cytochemical method, using peroxidase-++--antiperoxidase complex, an immune positive reactivity to ++leu enkephalin has been revealed in neurons of the substantia nigra, in the grey substance of the aqueduct area, in the posterior nucleus of the cochlear nerve, in the ventral part of the giant-cellular reticular nucleus in the nucleus of the solitary tract and in capillaries of the brain also. By means of some ultrastructural investigations certain places have been determined where synapsis and deposition of neuropeptides take place. These are specialized endotheliocytes, pericytes and neurons, situating especially close to the capillary wall.