Afferent connections of the median preoptic nucleus in the rat: anatomical evidence for a cardiovascular integrative mechanism in the anteroventral third ventricular (AV3V) region.

The afferent connections of cell groups in the anteroventral third ventricular (AV3V) region were investigated using wheat germ agglutinin-horseradish peroxidase conjugate injections into the AV3V area. The median preoptic nucleus was found to receive a unique set of inputs from the subfornical organ, the paraventricular nucleus of the hypothalamus, the parabrachial nucleus, the nucleus of the solitary tract and the ventrolateral medulla. As each of these structures has been implicated in various aspects of cardiovascular regulation, it is likely that the cardiovascular effects of AV3V lesions are due at least in part to median preoptic damage.