Mechawar - Post-mortem brain research

Question 1

What is one fact about the difference between human and rodent brains that accounts for the impossibility of translating some findings from preclinical research to clinical?

Answer 1

White matter in humans accounts for about 50% of total cortical volume, compared to 12% in mice

Question 2

True or false: although the human brain is more complicated in its connectome, it doesn’t have cell types unique to its species.

Answer 2

False: evidence was found for unique human cell types (GABA)

Question 3

What data gathered for patients that died by suicide by the brain bank is significantly subjective?

Answer 3

Modified Childhood Experience of Care and Abuse (CECA) interview

Question 4

What methods of preservation are used for human brains? What do they allow?

Answer 4

Formalin-fixation: Formalin fixation is commonly used for preserving tissues for histological examination. It maintains the architecture of tissues, allowing for microscopic examination of cellular structures and histopathological analysis.

Snap-freezing: Snap-freezing is often used to preserve samples for biochemical and molecular analyses. It retains the native state of proteins, nucleic acids, and other molecules, making it suitable for techniques such as protein analysis, RNA/DNA extraction, and enzymatic assays.

Question 5

How can the quality of postmortem tissue be assessed? List some procedures

Answer 5

Biochemical quality markers

• pH: more degradation = the more acidic
• RNA integrity
• Agonal Factor Score (AFS)
• Biomolecule integrity (RNA, miRNA, histone mod., protein, etc.)

Question 6

True or false: epigenetic marks quickly degrade after death.

Answer 6

False, pretty stable