Fig. 5: Model of NMJ synaptic structural changes in response to miniature event decline during ageing.
From: Miniature neurotransmission is required to maintain Drosophila synaptic structures during ageing
Miniature event frequency declines during ageing. In response, synaptic bouton diameters decrease and there is an increase in the number of small boutons with only a single active zone. All of these observations are consistent with young multiple active zone boutons fragmenting into smaller single active zone boutons as animals age. Reducing miniature events can accelerate this bouton fragmentation process in young animals while increasing miniature event frequency can delay synapse fragmentation in ageing animals.
