Age-associated neurodegenerative diseases such as Alzheimer's disease are characterised by neuronal
impairment that leads to cognitive deficits. As certain affected neurons depend on trophic factors such as
neurotrophins (NTs), impairment in NT function has been suggested to be a component of neuronal
damage associated with such disorders. Age-related neurodegenerative diseases are also characterised by high
levels of proinflammatory cytokines such as tumour necrosis factor alpha (TNFα) in the CNS. Because
TNFα receptors and certain NT receptors share a high degree of homology and are capable of activating
similar signalling pathways, one possibility is that altered cytokine levels may affect NT function in the aged
or diseased CNS. Here we wish briefly to review the evidence suggesting a role for cytokine and NT in the
onset of age-associated neurodegenerative diseases. We propose that cytokine/NT interactions may alter
neuronal homeostasis, thus possibly contributing to some of the neuronal degeneration occurring during
such age-associated CNS diseases.