Ageing can have profound effects on the post-mitotic organ of behaviour, the brain. As yet the precise causes of these deleterious effects are unknown. However, clear insights into the putative mechanisms and consequences of ageing in the CNS have been achieved through the use of invertebrate models. It is now clear that ageing alters the endogenous properties of neurones, their morphology, the efficacy of the connections that the neurones make with their targets and may even lead to neurone loss. While the precise mechanisms underlying these changes are presently unclear clues from post-mitotic organisms such as C. elegans have provided putative targets which are currently being investigated. It is clear to date that the age-induced changes in CNS function observed in invertebrates are conserved in mammalian species and that further work on invertebrates may provide informative insights in to the mechanisms of neuronal ageing.