The Brain Observatory at the University of California San Diego, directed by Jacopo Annese, has made available as part of its Digital Brain Library an atlas of H.M.’s brain. H.M., now known to be Henry Molaison, is one of the best known case studies in memory research. Molaison experienced profound amnesia following a bilateral medial temporal lobectomy and was subsequently studied for more than 50 years. Following his death in 2008, Molaison’s brain was donated to science and sectioned into more than 2400 slices (right), a procedure that was aired live on the web (see a previous AHP post on this process here). As described on the site,

In December 2009, Annese and his team at The Brain Observatory dissected H.M.’s brain into 2,401 thin tissue slices that have been preserved cryogenically in serial order. The collection was meant to support the histological examination of the brain and to better understand the neurological basis of human memory function. While the brain was being sliced, we collected an unabridged series of digital images of the surface of the block each corresponding to individual tissue sections. These images were archived and used to create a 3-D model of the whole brain. A regular series of sections through the brain was stained and digitized at a resolution of 0.37 microns per pixel to reveal cellular-level features. These virtual sections, a matching series of anatomically delineated images, and data from postmortem MRI of the specimen were combined into an atlas of patient H.M.’s brain.

The atlas was conceived as a web-accessible resource to support collaboration and retrospective studies.

Project HM can be explored in full here.