Synapses, language, and being human
Humans' ability to cope with the challenges they meet in life is transmitted almost exclusively through the medium of language. We have yet to fully map out the circuits of the human brain, the genes acting on them, and the processes they control that yield this distinct human quality. However, the findings of Sia et al. (1), on page 987 of this issue, bring us a step closer. The authors have determined that a secreted protein called sushi repeat–containing protein X-linked 2 (SRPX2) promotes mammalian vocalization by controlling the formation of synapses in the mouse cerebral cortex. Expression of this protein is known to be repressed by the transcription factor foxhead box protein P2 (FOXP2), which has been implicated in human language acquisition. A link between these two factors and synaptogenesis may have played a role in the evolution of the neural circuits associated with human language and cognition, as well as the pathogenesis of language disorders.
Science. 2013 Nov 22;342(6161):944-5. doi: 10.1126/science.1247515.
Cognitive and Linguistic Sciences, Brown University, 190 Thayer Street, Providence, RI 02912, USA.