BEHAVIOR AND ADRENAL WEIGHTS OF NON-STRESSED RATS WITH SELECTED LIMBIC LOBE LESIONS

Aggressive behavior and adrenal enlargement are exhibited in stressed rats following electrolytic septal lesioning. Both these responses are prevented by prior ablation of the amygdalae. It is not clear whether adrenal hypertrophy results solely from modifications of the pituitary-adrenal axis at the hypothalamic level, or is induced via the hypothalamus through modulations of neurogenic stressors at higher levels. Agonistic responses of lesioned animals to excessive handling and provocations during behavioral testing may influence the hypothalamus resulting in increased pituitary-adrenal function and adrenal hypertrophy. In these studies influences of septal, amygdaloid, and septal-amygdaloid (dual) lesions on adrenal weights were investigated in non-stressed (untested) rats. The presence and extent of septal and amygdaloid lesions were ascertained histologically. No significant differences were found in mean adrenal weights of any lesioned group when compared with either the normal intact or sham-operated control groups. Moreover, no significant differences were found in adrenal specific weight" in lesioned animals compared with adrenal "specific weight" in animals of either control group. © 1969."