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Slicing of the Brain of Patient H.M.

The brain of Patient H.M.

The brain of H.M. is embedded in a gelatin block.

(Image credit: Jacopo Annese)

Patient H.M. became an iconic case in neuroscience when he developed a peculiar form of amnesia after parts of his brain were removed during surgery in 1953. After H.M.'s death in 2008, Jacopo Annese and his colleagues at the Brain Observatory in San Diego dissected his frozen brain into 2,400 thin slices, to learn about his brain lesions that caused his amnesia.

The frozen brain

Image of the frozen brain at the level of the temporal lobes during the cutting procedure.

(Image credit: Diego Mariscal)

Image of the frozen brain at the level of the temporal lobes during the cutting procedure.

Cutting process

Jacopo Annese dissecting the brain of H.M.

(Image credit: Diego Mariscal)

Jacopo Annese dissecting the brain of H.M.

Cutting process

Image of the frozen brain at the level of the frontal lobes during the cutting procedure.

(Image credit: Annese et al.)

Image of the frozen brain at the level of the frontal lobes during the cutting procedure.

Preparing solutions

Researcher Paul Maechler making a solution to treat the brain tissue.

(Image credit: Jacopo Annese)

Researcher Paul Maechler making a solution to treat the brain tissue.

Brain slides

Tissue sections mounted on glass slides before staining.

(Image credit: Annese et al.)

Tissue sections mounted on glass slides before staining.

Brain slides

Researcher Colleen Sheh examining a thin slice of the brain.

(Image credit: Jacopo Annese)

Researcher Colleen Sheh examining a thin slice of the brain.