ELECTRON MICROSCOPIC OBSERVATIONS OF EARLY CHANGES IN THE VENTROMEDIAL HYPOTHALAMUS OF THE MOUSE FOLLOWING GOLDTHIOGLUCOSE*,†,‡

The lesion of the ventromedial region of the mouse hypothalamus which results from a single parenteral injection of goldthioglucose, has been studied at both light3,7,12,15.,18,27) and electron microscope levels13). There is evidence from distribution studies following injection of labeled goldthioglucose23), and neutron activation of sections of the hypothalamus of mice treated with the unlabeled compound4,5) which indicates that the drug enters the neural compartment rapidly. Existing studies13) with the electron microscope following goldthioglucose administration are limited to 12‐and 96‐hour post‐injection intervals. The present experiments were undertaken to ascertain the ultrastrctural changes evident in the ventromedial nucleus of the hypothalamus at closely spaced time intervals during the first 24 hours after treatment with the compound.