Anchor attempts to close that gap.

Users can zoom from the whole brainstem seen on MRI down to individual neurons while maintaining their precise spatial relationships. The researchers have made the atlas freely available online, external, hoping it becomes a reference tool for neuroscientists, neurologists and neurosurgeons worldwide.

Its applications could also extend well beyond anatomy.

By comparing healthy brainstem maps with diseased tissue, scientists may better understand disorders ranging from Parkinson’s disease and stroke to Alzheimer’s disease and sudden infant death syndrome (SIDS). More precise maps could also help neurosurgeons navigate one of the brain’s most delicate regions with greater confidence.

Anchor is not a diagnostic tool. Instead, its greatest value lies in the questions it could help answer.

Partha Mitra, a brain scientist at the prestigious New York-based Cold Spring Harbor Laboratory who has worked with SGBC, says detailed brain atlases like this could have a “transformative impact” on the study of neurological disease by revealing, cell by cell, how brains affected by conditions such as Alzheimer’s or autism differ from healthy ones.

They could also help explain how infections, including Covid-19, trigger long-term neurological damage, Mitra told the BBC.

Using brain stroke as an example, Folkerth says the atlas has uncovered new features that could help doctors preserve brain tissue that is injured but not yet beyond repair, potentially improving patient outcomes. Other scientists say the atlas could also help neurosurgeons navigate the brainstem more safely.

Part of this atlas’s appeal lies in its simplicity. Built from high-resolution images of thin slices of post-mortem brain tissue, the approach makes detailed, cell-level mapping affordable.

That, says Mitra, has made it possible to chart the human brainstem at an unprecedented scale.

The achievement reflects a broader transformation in neuroscience, where progress increasingly depends as much on engineering and computation as on biology.

Around 20 scientists spent 18 months at SGBC manually analysing more than 200 brain sections, combining MRI scans, microscopic anatomy and 3D reconstruction into a single digital atlas. The centre now brings together more than 200 researchers, engineers and technicians working with collaborators around the world.

The result helps address a surprising gap in neuroscience.