Strengthening the remaining synapses.

Abstract

Neuroscience Working memory depends in part on the proper activation of neural circuits in a brain area called the dorsolateral prefrontal cortex (DLPFC). In primates, DLPFC performance during working memory tasks improves through adolescence. Synaptic pruning eliminates unwanted or imprecise connections and strengthens the remaining connections. Chung et al. found that the excitatory synapses on a crucial subgroup of interneurons in the monkey DLPFC also undergo pruning during adolescence. Such synapses are partially regulated by an enzyme called ErbB4. This enzyme exists in alternative splice variants. During development, there is a shift in the dominant alternative splice transcripts, which is accompanied by fewer but stronger excitatory synapses. Shifts in ErbB4 splicing thus modulate the pruning of excitatory synapses on these interneurons during maturation. Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1610077114 (2017).