Reduction of CCK-8 binding in the nucleus of the solitary tract in unilaterally nodosectomized rats.

Cholecystokinin octapeptide (CCK-8) binding sites were examined in the caudal hindbrain of unilaterally nodosectomized and intact rats by in vitro autoradiography with 125I-CCK-8. Unilateral nodosectomy caused a significant reduction in CCK-8 binding in the caudal medial nucleus of the solitary tract (NST) on the side ipsilateral to the nodose ganglionectomy. Examination of other caudal hindbrain regions exhibiting CCK-8 binding did not reveal changes in binding in nodosectomized animals compared to controls. These findings suggest that the CCK receptors in this brain region may be located on terminals of vagal afferent neurons.