Lesions of the area postrema (AP) and adjacent caudal medial nucleus of the solitary tract (cmNTS) cause significant changes in water and sodium balance. Lesioned rats display a permanent polydipsia, which in part is due to a primary polyuria. Water-to-food ratios are elevated chronically. Lesioned rats are unable to concentrate their urine as well as controls. In addition, lesioned rats overdrink in response to 24-h water deprivation. This lesion also causes a natriuresis and an overconsumption of 3% NaCl solution. These findings establish the AP-cmNTS as an important part of the neurocircuitry underlying water and sodium balance.
- Copyright © 1984 the American Physiological Society