H.M.’s Brain Dissection

H.M.’s Brain Dissection

Researchers at UCSD are dissecting the brain of amnesia patient H.M. and streaming live video of the process online. The process began on Wednesday and can be viewed online at through today.

Henry Molaison, referred to as H.M., developed amnesia in 1953 after undergoing an experimental surgery to treat epilepsy. Scientists at MIT, including MIT Professor Suzanne H. Corkin, have studied H.M. since 1966 to gain insight into how the brain forms memories. Molaison died last December at the age of 82.

The man who could not remember has left scientists a gift that will provide insights for generations to come: his brain, now being dissected and digitally mapped in exquisite detail.

Molaison — known during his lifetime only as H.M., to protect his privacy — lost the ability to form new memories after a brain operation in 1953, and over the next half century he became the most studied patient in brain science.

He consented years ago to donate his brain for study, and last February Dr. Jacopo Annese, an assistant professor of radiology at the University of California, San Diego, traveled across the country and flew back with the brain seated next to him on Jet Blue.

Just after noon on Wednesday, on the first anniversary of Molaison’s death at 82 from pulmonary complications, Annese and fellow neuroscientists began painstakingly slicing their field’s most famous organ. The two-day process will produce about 2,500 tissue samples for analysis.

A computer recording each sample will produce a searchable Google Earth-like map of the brain with which scientists expect to clarify the mystery of how and where memories are created — and how they are retrieved.

“Ah ha ha!” Annese said, as he watched a computer-guided blade scrape the first shaving of gray matter from Molaison’s frozen brain. “One down, 2,499 more to go.”

“It’s just amazing that this one patient — this one person — would contribute so much historically to the early study of memory,” said Dr. Susumu Tonegawa, a professor of neuroscience at the Picower Institute for Learning and Memory. “And now his brain will be available” for future study.

Good fortune and very bad luck conspired to make Molaison one of science’s most valuable resources and most productive collaborators. Growing up in and around Hartford, Conn., he began to suffer seizures as a boy. The seizures grew worse after he was knocked to the ground by a bicycle rider, and by the time he was 26 they were so severe he consented to an experimental brain operation to relieve them.

His doctor, the prominent brain surgeon William Beecher Scoville, suctioned out two slug-sized slivers of tissue, one from each side of the brain. The operation controlled the seizures, but it soon became clear that the patient could not form new memories.