Measurement of pre- and post-synaptic proteins in cerebral cortex: effects of post-mortem delay.

Journal article

Assessments of synaptic density in human brain are often based on measurements of synaptic proteins. Little information is available on their post-mortem stability. We have investigated this by ELISAs of the pre-synaptic proteins syntaxin and synaptophysin, and the post-synaptic protein PSD-95, in rat and human cortex. The rat brains were cooled in situ from 37 to 20 or 4 degrees C over 3 h, and then kept at 20 or 4 degrees C for a further 24-72 h, to simulate post-mortem storage at room temperature or in a mortuary refrigerator. Synaptophysin and PSD-95 levels in rat cerebral cortex were not significantly decreased after 72 h of incubation at 20 degrees C. Syntaxin was stable for 24 h but decreased by 39-44% at 48-72 h. Storage at 4 degrees C resulted in a similar reduction of syntaxin levels over 72 h. In human brain tissue from 160 people aged 24-102 years, post-mortem delay had little effect on synaptic protein levels in superior temporal cortex, but was associated with a decline in PSD-95 and syntaxin in mid-frontal cortex after 24 h. The more robust stability of synaptophysin may be related to its multi-transmembrane structure.

Authors: Siew, L; Love, S; Dawbarn, D; Wilcock, G; Allen, S

• Publication status: Published
• Journal: Journal of neuroscience methods
• Volume: 139
• Issue: 2
• Pages: 153-159
• Publication date: 2004-10-01
• DOI: 10.1016/j.jneumeth.2004.04.020
• EISSN: 1872-678X
• ISSN: 0165-0270
• Language: English
• Keywords: Qa-SNARE Proteins; Rats; Adult; Middle Aged; Intracellular Signaling Peptides and Proteins; Animals; Nerve Tissue Proteins; Time Factors; Postmortem Changes; Aged; Humans; Cerebral Cortex; Synapses; Aged, 80 and over; Membrane Proteins; Synaptophysin