Gene in mice reduces background activity and improves focus ^{CEFR B2}

In a study led at Rockefeller University and published in Nature Neuroscience, researchers scanned the genomes of nearly 200 outbred mice from eight parental lines, some with wild ancestry, to model human genetic diversity. That broad strategy revealed a strong genetic effect in the prefrontal cortex, the region that governs attention. High-performing animals had much lower Homer1 levels in this area, and the gene lay in a locus that accounted for almost 20 percent of the variation in attention across the mice.

Further experiments identified two short Homer1 isoforms, Homer1a and Ania3, as the key contributors. Reducing these isoforms during a narrow adolescent window made mice faster, more accurate and less distractible across several tests; the same intervention in adult mice had no measurable effect, implying a critical developmental period for Homer1’s influence.

At the cellular level, lowering Homer1 in prefrontal neurons raised the number of GABA receptors—the molecular "brakes" of the nervous system. This shift created a quieter baseline and allowed focused bursts of activity when cues appeared, so neurons conserved firing for important moments instead of firing indiscriminately. Priya Rajasethupathy noted the surprising result that more attention linked to lower baseline activity. The authors suggest these findings point to a possible new path for therapies that calm rather than stimulate brain circuits, and they plan further study of Homer1 genetics and a splice site that "can be pharmacologically targeted" to adjust brain signal-to-noise levels.