Ultrastructure of hypothalamic and medullary lesions caused by an aliphatic triamine

The administration of an aliphatic triamine, 3,3'-methylimino-bis-(N-methylpropylamine), was used to produce non-necrotizing lesions in the hypothalamus and medulla oblongata of rats. The distribution of the lesions in the hypothalamus was similar to that produced by goldthioglucose, and consisted ultrastructurally of marked distention and edema of the extracellular space, with no confined to the dorsal aspect, in the region of the area postrema. The data suggest that the absence of blood-brain barrier in these sites plays a role in the production of lesions, at least in the initial stages, as has been proposed for goldthioglucose lesions.