Cytokine/neutrophin interaction in the aged central nervous system

Age-associated neurodegenerative diseases such as Alzheimer's disease are c haracterised by neuronal impairment that leads to cognitive deficits. As ce rtain affected neurons depend on trophic factors such as neurotrophins (NTs ), impairment in NT Function has been suggested to be a component of neuron al damage associated with such disorders. Age-related neurodegenerative dis eases are also characterised by high levels of proinflammatory cytokines su ch as tumour necrosis factor alpha (TNF alpha) in the CNS. Because TNF alph a receptors and certain NT receptors share a high degree of homology and ar e capable of activating similar signalling pathways, one possibility is tha t altered cytokine levels may affect NT function in the aged or diseased CN S. Here we wish briefly to review the evidence suggesting a role for cytoki ne and NT in the onset of age-associated neurodegenerative diseases. We pro pose that cytokine/NT interactions may alter neuronal homeostasis, thus pos sibly contributing to some of the neuronal degeneration occurring during su ch age-associated CNS diseases.