Scientists map the mouse motor cortex in 16 subregions

A new study from the University of Basel, the Friedrich Miescher Institute for Biomedical Research, and the Allen Institute has produced the most detailed map yet of the mouse motor cortex. The atlas could sharpen research into ALS, frontotemporal dementia, and how movement circuits are organized across the brain.

Why it matters: - The mouse motor cortex is a key model for studying how the brain plans and controls movement. - A more precise map could help researchers identify which brain cells are vulnerable in diseases such as ALS and frontotemporal dementia. - The atlas may also help scientists trace how disease spreads through connected brain regions.

What happened: - Researchers from the University of Basel, the Friedrich Miescher Institute for Biomedical Research, and the Allen Institute mapped the mouse motor cortex into 16 distinct subregions. - The study was published September 23, 2026. - The work draws on 547 tracing experiments that followed how signals leave the motor cortex and reach other parts of the brain. - The map is available to researchers through BrainGlobe.

The details: - The team grouped areas that send similar signals and found 16 subregions with distinct connectivity patterns. - The subregions are arranged in three rows. - A back-to-front axis separates areas tied more to sensory input, such as touch and body position, from areas tied more to planning and decision-making. - A side-to-side axis separates regions linked to different body parts, from trunk and limbs to face and mouth. - The researchers confirmed the structure with two additional methods: tracing individual neurons and analyzing the types of brain cells present. - All three approaches supported the same 16-subregion model. - The study also found that the primary motor cortex and secondary motor cortex work together as they send signals to the brainstem and spinal cord. - That pattern challenges the older view that the two areas are arranged mainly in a hierarchy. - The researchers used the Allen Institute’s Mouse Brain Atlas to support the analysis. - The online BrainGlobe tool gives researchers a shared reference point for aligning data.

Between the lines: - The study suggests the motor cortex is organized with far more internal structure than the broad primary-versus-secondary split used in many brain atlases. - That kind of precision matters because disease research often depends on knowing exactly which cells and circuits are affected first. - Hongkui Zeng, executive vice president and director of Brain Science at the Allen Institute and a senior author, said precise wiring is essential for developing effective treatments for brain diseases. - Silvia Arber, professor of neurobiology at the University of Basel and the Friedrich Miescher Institute for Biomedical Research, said the motor cortical modules interact with output regions with very high precision and share the same wiring logic across the cortex. - Antonio Falasconi, one of the study’s first authors, said the unified map should help researchers align their data and accelerate progress. - Harsh Kanodia, another first author, said combining wiring and cellular datasets revealed a much more precise blueprint of motor cortex organization.

What’s next: - Researchers can now test which of the 16 subregions contain cells most vulnerable to ALS and FTD. - Future work could examine how this 16-subregion framework compares with motor cortex organization in other species, including humans. - The map may also serve as a reference for studying how movement circuits connect with sensory and decision-making systems.

The bottom line: - The mouse motor cortex is more finely organized than previously recognized, and that new detail could make it easier to study movement, brain wiring, and neurodegenerative disease.