Genes involved in calcium buffering and neuroprotection are upregulated in speech circuits because larynx muscles require high neuronal activity and generate toxicity.

“Other genes that surprised us were genes involved in calcium buffering neurop protection like a parvamine or heat shock proteins. So when your brain gets hot these proteins turn on and we couldn't figure out for a long time why is that the case and then the idea popped to me one day and said ah when I heard the larynx is the fastest firing muscles in the body. All right. In order to vibrate sound and and modulate sound in the way we do, you have to control, you have to move those muscles, you know, three to four to five times faster than just regular walking or running. And so, um, when you stick electrodes in in the brain areas that control learn vocalizations in these birds and I think in humans as well, uh, those neurons are firing at a higher rate to control these muscles. And so what is that going to do? You're going to have lots of toxicity in those neurons unless you upregulate molecules that take out uh the extra load that is needed to control the larynx.”