Interaction between hypothalamus, amygdala and septal area in the control of sodium chloride intake

The studies were made in rats employing the standard two-bottle self-selection procedure. Rats with increased salt intake due to lesions in the amygdaloid complex or in septal area diminished their intake following hypothalamic lesions which in the intact rat causes decreases. When the hypothalamic lesions were made first, amygdaloid or septal lesions did not induce any change. Rats with decreased salt intake because of amygdaloid lesions showed an augmented ingestion after septal lesions but if septal lesions were made first the increased intake elicited was not modified by amygdaloid lesions which in the intact rat causes decreases. It was concluded that the hypothalamus is the main structure controlling sodium intake and that the amygdala and septal area have modulating influences on the hypothalamus. In turn, septal area overcomes the action of the amygdala.