Astrocytes and the ageing synapse

Neurons are generally regarded as the computational units of the brain and communicate at specialist structures called synapses. Synapses are plastic and show structural and functional modifications over time, changes which are thought to be the basis of learning and memory. Ageing is generally associated with cognitive decline and it is now thought that this is not caused by the loss of neurons per se but by a loss of synapses and/or perturbed synapse function. Astrocytes are the main type of glial cell in the mammalian brain and play key roles at all stages of the synaptic life cycle from formation to elimination. In this Mini Review, I aim to give an overview of our current understanding of how ageing impacts this cell type, arguing that impaired astrocyte function is likely a major contributor to ageing-related cognitive decline.