Symmetric Bihemispheric Sectioning of the Human Postmortem Brain

Begin with a human postmortem brain in the ventral position.

Next, cut the brainstem transversely at the upper portion of the pons, close to the cerebrum base.

Inspect the substantia nigra, a midbrain structure, and neighboring structures for any abnormalities.

Dissect the olfactory bulbs along with their tracts.

Now, position the brain dorsally and cut the corpus callosum through the medial longitudinal fissure to separate the hemispheres.

Carefully examine each hemisphere for any anomalies.

Next, position the hemispheres flat with their medial surfaces facing down.

Cut through the cerebral hemispheres from the frontal to occipital poles to obtain thick sections.

 Then, arrange the sections in anatomical order with their coronal surfaces facing up for inspection. Look for any abnormalities.

Dissect rectangular tissue blocks from different cerebral regions.

Place these tissue blocks in labeled histocassettes for further analysis.

Facing the base of the brain and using a scalpel, cut the brainstem transversely at the upper portion of the pons as close as possible to the base of the cerebrum. Carefully inspect the substantia nigra for pallor, and inspect other neighboring structures. Using an audio recording device, take note of any unusual appearance of the brain in comparison to a normal brain. Here, the olfactory bulb and tract of the left and then right hemispheres are being dissected.

Flip the brain back over, and using a sharp knife, follow a frontal occipital direction to separate the two hemispheres by cutting the corpus callosum centrally through the medial longitudinal fissure. Inspect each side of each hemisphere for possible anomalies. After taking as many pictures as necessary, including perpendicularly to the brain to capture the entire cortical surface, place the two hemispheres flat lying on their medial aspects, with the frontal lobes facing away from the investigator and with their centers touching.

Using a sharp knife, manually cut through both cerebral hemispheres, starting at the frontal poles and move towards the occipital poles through the entire length of the hemispheres, to obtain two series of one centimeter thick slabs of brain tissue. Position the brain slabs in an anatomically organized and symmetric sequence on a flat white surface with a ruler printed on it for photographing. Ensure that the slabs coronal surfaces are visible for direct eye inspection and digital photography.

Use cutting surfaces with printed millimetric grids on both sides to localize brain structures, sizes, and possible abnormalities in a more accurate manner. Take notes of any unusual aspect of the brain in comparison to a normal brain. Next, using a sharp scalpel, manually dissect smaller, rectangular blocks of brain tissue. For each established cerebral region. Follow the proposed cerebral region Collection Scheme described in this table. Create de-identifying codes to label the histocassettes by generating random or semi-random numbers for each case, where AD stands for Alzheimer's Disease study, 16 stands for the year the autopsy is performed, and 0001 is a progressive accession specimen number. Place each tissue block in separate histocassettes.