Pathways disrupted in aphagia and adipsia following diencephalic damage.

The neuroanatomical pathways of the rat disrupted in aphagia and adipsia were investigated using the Fink-Heimer and autoradiographic anterograde tracing procedures. Following lesions in the lateral hypothalamic complex (LHC) which produce aphagia and adipsia as well as the injection of labeled proline into the LHC, projections were seen in the nucleus accumbens, the preoptic area, the lateral habenular nucleus, the ventromedial hypothalamic nucleus, the nucleus reuniens, the parafascicular nucleus, the posterior hypothalamus, the zona incerta, the central gray matter, the tegmentum, the substantia nigra (pars compacta), the ventral tegmental area of Tsai and the parabrachial area. However, axonal degeneration and not radioactive label were observed in the mediodorsal thalamus, the superior colliculus, the medial pontine gray, the mesencephalic nucleus of the Vth nerve, the motor nucleus of V, the raphe nuclei and the crus cerebri fiber system. The LHC is discussed as a region which connects with other levels of the central nervous system known to be related to the act of ingestion.