Autoradiographic localization of substance P receptors using 125I substance P

This paper describes a method for localization of substance P receptors in the rat central nervous system using 125I labeled substance P in an autoradiographic procedure. Particularly high densities of substance P receptors were observed in the olfactory bulb, dentate gyrus, amygdala, superior colliculus, and locus coeruleus. Surprisingly low densities of substance P receptors were found in the substantia nigra pars reticulata, a region which contains high concentrations of substance P.