The aim of work was to study the peculiarities of apoptosis regulation in neurosecretory centers of old (aged 18 months) mice treated with immunomodulator interferon alpha (IFN-alpha) as compared to young (aged 2 months) mice. It was shown that age-related apoptosis activation in supraoptic (SON) and paraventricular (PVN) nuclei was mediated by different molecular mechanisms and could result from the alterations of the balance of apoptosis-associated proteins, including the synthesis of proapoptotic (Bax) and antiapoptotic (Mcl-1, Bcl-2) molecules. Besides, the apoptosis signal cascade in young mice treated with IFN-alpha was identical in both nuclei, whereas in old mice there were some differences between SON and PVN.