The hypothalamo-neurohypophysial tract of
young, adult and aged male hamsters was studied at
lateral and ventral regions of hypothalamus by means of
electron microscopy. Neurosecretory swelling axons
(Herring bodies) were usually found as classically
described containing abundant neurosecretory granules,
mitochondria, few microtubules and profiles of smooth
endoplasmic reticulum in al1 groups of age. However, in
aged hamsters, starting at 18-month-old subjects, we
observed that the size of some neurosecretory axons was
highly increased. Autophagic and degenerative features
were seen in the larger ones. These data could suggest
abnormal axonal storage or axonal transport blocked
during aging. The implications in the role of hypothalamus-
neurohypophysial system during aging are
discussed