TNNChennai— Scientists at the Indian Institute of Technology Madras (IIT M) have built a three-dimensional atlas of the human brainstem, charting more than 200 structures at the resolution of individual cells — a feat that experts say could transform how doctors diagnose and treat neurological diseases.The brainstem, a stalk-like structure connecting the brain to the spinal cord, controls breathing, sleep, wakefulness and movement. Damage to it underlies some of the most severe neurological conditions. Doctors have long worked with maps too vague to show precisely which cells were affected. The new atlas, named ANCHOR, changes that, IIT M announced on Friday.It works like a ‘Google Earth’ of the brainstem. A doctor can begin with an MRI scan, then zoom down through tissues, through fibre tracts that work like internet cables carrying signals between brain regions, all the way to a single cell. To distinguish cell types, researchers applied eight chemical dyes, called immunostains, across several hundred tissue slices, lighting up specific proteins in each cell.The atlas, which spans brains from the prenatal period through adulthood, is available free at anchor.humanbrain.in. “These maps will help identify specific cell populations affected in brainstem lesions, which could be critical for clinical applications,” said Ajay Kumar Sood, principal scientific adviser to the government of India.ANCHOR was unveiled at the 3rd BRICS Neuroscience Symposium at IIT M conducted from June 5 to 7. The institute collaborated with CMC Vellore, Govt Kilpauk Medical College, Sri Ramachandra Institute of Higher Education and Research, and MediScan Systems.The atlas is the latest advance from the Sudha Gopalakrishnan Brain Centre at IIT Madras, which in December 2024 released DHARANI — a detailed atlas of the human fetal brain that became a large publicly accessible digital dataset. Researchers froze five fetal brains from pregnancies that did not go to term, sliced them into slivers one-tenth the width of a human hair and spent nearly a year digitally stitching each brain back together. When imported equipment ran short during the Covid-19 lockdown, the team built the technology themselves.The centre is The team is also mapping brains affected by rabies, dementia and Alzheimer’s disease.ANCHOR is the centre’s next leap: from the fetal brain to the adult brainstem, and from anatomy to the chemistry of individual cells. “We envision that these maps and atlases will have significant implications for neuroscience and neuromedicine,” said professor Mohanasankar Sivaprakasam, who heads the centre. “We have a mission to image more than 100 whole brains across the human lifespan, from womb to tomb, and of various neurological diseases.” The centre draws on more than 200 researchers and 20 international collaborators.GraphicWhat is itA detailed, free, three-dimensional map of the human brainstemWhat makes it differentDoctors and researchers can zoom from a hospital MRI scan all the way down to a single brain cellWhat does it cover200+ brainstem structures, including the pathways that carry signals between brain regions, across fetal, childhood and adult brainsWho can use itAnyone — researchers, doctors and scientists worldwide. anchor.humanbrain.in is open accessWhat diseases could it help?Stroke, tumours, Alzheimer’s, dementia and rabies — any condition that damages the brainstem.
