Histological Differences between Ventromedial Hypothalamic Neurones of Well Fed and Underfed Rats

Abstract

ELECTROPHYSIOLOGICAL recording in the ventromedial hypothalamus has shown that feeding or administering glucose to hungry animals causes an increase in the activity of the cells concerned, whereas lateral hypothalamic activity tends to be lowered^1–3. These reactions are consistent with the apparent role of the ventromedial hypothalamus in limiting the intake of food and the lateral hypothalamus in stimulating it⁴. Histological observations of other parts of the nervous system have shown that increased functional activity of nerve cells can be followed by increases in the size of the nucleoli, and decreased activity by decreases in the size of these organelles^5–8. Results reported here show that nucleoli in ventromedial hypothalamic neurones are larger in well fed than in hungry rats.