Mouse brain study: returning to the immature phase to improve learning
Research
Researchers in the United States have found that the auditory system in the adult mouse brain can be induced to revert to an immature state, improving the animals’ ability to learn new sounds, reports Scientific American.
The team, working in various institutes and hospitals in Tennessee, had previously shown that developmental windows seem to be controlled by adenosine and that its levels increase after the critical neural development period. They found that this increase inhibits communication between cells in the auditory cortex and the thalamus.
Jay Blundon, a developmental neurobiologist at Saint Jude Children’s Research Hospital in Memphis, led the study. He and his colleagues developed various experiments to test whether inhibiting adenosine signaling would reinstate plasticity in the auditory cortex. They found that cells in the auditory cortex of test mice lacking the adenosine receptor responded to a broader range of frequencies than those of wild-type mice, showing increased plasticity.
In another experiment, the group tested whether blocking adenosine signaling with a drug would have the same effect in healthy mice. “This [signaling] mechanism, if blocked, is sufficient to extend critical plasticity to late adulthood,” said Stanislav Zakharenko, senior author for the study. Extrapolating to humans, he said, “Learning a language is very easy for two- to three-year-olds, but language learning courses for adults aren’t very effective, even though adults are still capable of learning other skills effectively. But if I take a language course while inhibiting adenosine production or signaling in the thalamus, I would acquire the information quicker, retain it for longer, and maybe lose my accent.”
Source: Scientific American; Blundon JA et al. Restoring auditory cortex plasticity in adult mice by restricting thalamic adenosine signaling. Science. 2017 Jun 30;356(6345):1352-1356.