A team led at Rockefeller University by Priya Rajasethupathy scanned the genomes of nearly 200 genetically diverse mice to find genes that affect attention. Their results, published in Nature Neuroscience, pointed to a strong influence in the prefrontal cortex. Mice that performed best on attention tasks had far lower levels of the Homer1 gene in that region, and the locus explained almost 20 percent of the variation in attention.
Follow-up experiments showed the effect came from two short isoforms, Homer1a and Ania3. Experimentally reducing these isoforms in adolescent mice improved speed, accuracy and resistance to distraction across multiple tests. The same genetic change in adult mice produced no effect, suggesting a critical early-life period for Homer1’s action.
At the cellular level, lowering Homer1 increased GABA receptors in prefrontal neurons. This change quieted baseline activity and produced focused bursts when cues appeared, so neurons conserved activity for important moments. The findings suggest new avenues for therapies that calm rather than stimulate brain circuits.
Difficult words
- genome — complete set of an organism's genesgenomes
- genetically — in a way related to genes or heredity
- prefrontal cortex — front brain area important for decision making
- locus — specific place on a gene or chromosome
- isoform — different form of the same proteinisoforms
- adolescent — young animal or person not yet adult
- GABA receptor — protein on neurons that responds to GABAGABA receptors
- baseline activity — usual level of neuron activity at rest
- resistance — ability to keep focus despite interruptions
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- How could a critical early-life period for Homer1 action change when we give treatments for attention problems?
- What might be the advantages and disadvantages of therapies that calm brain circuits instead of stimulating them?
- Do you think results from mice can help develop human treatments for attention? Why or why not?
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