Integrated morphology of neuronal catecholamines and neurophysin in the aged macaque

A new method for the simultaneous visualization of brain peptides and monoamine neurotransmitters was employed to analyze the integrated morphology of hypothalamic catecholamines and neurophysins in young and old monkeys. Immunocytochemical analysis using bovine neurophysin revealed a dual papulation of light and dark stained cells in the paraventricular nucleus in young and old macaques. In general, both populations of neurons stained with less density in old macaques indicating the possibility of a reduced content of neurophysin. Further analysis using specific neurophysin antisera for vasopressin or oxytocin revealed an appreciable decrease in the number of vassopressin-containing perikarya in the 20 year monkey whereas oxytocin-synthesizing neurons did not show a similar change in numbers with age. Qualitatively, terminal innervation patterns of hypothalamic catecholamines remained strikingly constant in spite of marked reductions in dark-stained neurophysin perikarya of the paraventricular nucleus.