Organization of some brain stem afferents to the paraventricular nucleus of the hypothalamus in the rat.

Brain stem afferents to subnuclei of the paraventricular nucleus of the hypothalamus were studied by the anterograde autoradiographic technique in the rat. The parabrachial nuclei and locus coeruleus project to the posterior, periventricular, parvocellular and dorsal divisions. The ventral medulla projects to the posterior, medial, lateral, parvocellular and dorsal divisions. The A1 catecholamine cell group projects to the posterior, medial, lateral, parvocellular and dorsal divisions, and the nucleus of the solitary tract to the parvocellular and dorsal divisions. The A1 region and the ventral medulla also project to the supraoptic nucleus.