This Podcast features an interview with David Sweatt and John Hablitz, senior authors of a Research Article that appears in the 23 June 2015 issue of Science Signaling, about the role of DNA methylation in synaptic plasticity. Making and recalling memories relies on synaptic plasticity, a collective term for changes in neuronal morphology or function that affect communication between neurons. Meadows et al. found that methylation of DNA was important for scaling of glutamatergic synapses, a type of synaptic plasticity, in cultured rat neurons. DNA methylation status controlled the expression of genes involved in glutamate signaling during multiplicative synaptic upscaling, a phenomenon in which receptor density increases simultaneously in each of a neuron's synapses. These findings illustrate that epigenetic mechanisms can coordinate cell?wide changes in synaptic function.