Friday, 10 July 2009

Singing Mice Clue To Human Language

Chapter 2 of NOT A CHIMP tells the story of the discovery of the FOXP2 gene, how, early on it was erroneously dubbed "the language gene" and how research on a human family with speech and articulation difficulties, bolstered by work on the gene in chimps, singing birds, bats and mice, had led to a deeper understanding of its involvement in the coordination of the rapid sequential processes involved in the assembly of the components of language into speech and the complex articulation of the vocal tract to produce speech sounds. Now a team led by Polly Campbell at the University of Florida has extended this species comparison angle still further by comparing singing mice with lab. mice and deer mice. Interestingly, the pattern of expression of FOXP2 was remarkably similar across all species and while expression in the cerebellum and other structures involved in vocalisations was strong, they found a particularly high signature in the thalamus - a half-way house in the brain whereby signals from the sense organs and receptors in gut and skin etc. (the so-called somatosensory system) are relayed to the cortex for higher-order processing. So, FOXP2 has an even broader remit in the brain. Not only involved in vocal communication, but in sensorimotor integration in general. It seems that the evolution of human language, and the role of FOXP2 in it, continues to benefit from very wide range of species comparison. This is what happens when you take the "chimp-human" exclusive blinkers off.

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