Highly read on www.jneurosci.org in December

In the brain, a drop in the activity of just one gene decreases neurons' ability to change the strength of their connections — a hallmark of age-related cognitive decline.

The gene, Bdnf, encodes a protein that helps neurons in cognitive centres of the brain to form connections called synapses. Cui-Wei Xie and her colleagues at the University of California, Los Angeles, analysed brain slices from young, middle-aged and aged rats. Aged rat brains showed a decrease in the addition of acetyl groups to histones — proteins that package up DNA — in the regulatory regions of the Bdnf gene, reducing the gene's expression. Treating the brain slices with chemicals that mimic the BDNF protein or inhibit histone deacetylation increased the density and strength of neuronal connections.

J. Neurosci. 31, 17800–17810 (2011)