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

Siew, Lai Khai; Love, Seth; Dawbarn, David; Wilcock, Gordon; Allen, Shelley J

doi:10.1016/j.jneumeth.2004.04.020

Cited by 50 publications

(36 citation statements)

References 16 publications

(16 reference statements)

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“…These findings are consistent with our study of the postmortem stability of synaptophysin in rat cortex over 24 hours. However, in the human, PSD-95 showed a significant decrease in protein levels with postmortem intervals greater than 24 hours (Siew et al 2004) as was also suggested by our PMI study in rat cortex. We included PMI in our statistical model and found that PMI did not influence synaptophysin levels, but did affect those of PSD-95, in the human.…”

Section: Discussionsupporting

confidence: 84%

“…The impact of postmortem stability was also considered. In rat cortex, previous studies have shown that synaptophysin and PSD-95 levels do not exhibit significant decreases with PMI less than 72 hours (Halim et al 2003;Hilbig et al 2004;Siew et al 2004). In human cortex, synaptophysin levels appear to be fairly robust over PMIs of less than 84 hours (but see Vawter et al 2002) (Honer et al 1992;Vawter et al 2002).…”

Section: Discussionmentioning

confidence: 92%

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Synaptophysin and postsynaptic density protein 95 in the human prefrontal cortex from mid-gestation into early adulthood

Glantz¹,

Gilmore²,

Hamer³

et al. 2007

Neuroscience

232

162

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Previous studies of postnatal synaptic development in human frontal cortex have shown that synaptic density rises after birth, reaches a plateau in childhood and then decreases to adult levels by late adolescence. A similar pattern has been seen in nonhuman primate cortex. These earlier studies in human cortex are limited, however, by significant age gaps in study subjects at critical inflection points of the developmental curve. Additionally, it is unclear if synaptic development occurs in different patterns in different cortical layers in prefrontal cortex (PFC). The purpose of this study was to examine synaptic density in human PFC across development by measuring two synaptic marker proteins: synaptophysin (presynaptic), and postsynaptic density-95 (PSD-95; postsynaptic). Western blotting was used to assess the relative levels of synaptophysin and PSD-95 in dorsolateral PFC of 42 subjects, distributed in age from 18 weeks gestation to 25 years. In addition, synaptophysin immunoreactivity was examined in each layer of areas 9 and 46 of PFC in 24 subjects, ranging in age from 0.1 to 25 years. Synaptophysin levels slowly increased from birth until age 5 and then increased more rapidly to peak in late childhood around age 10. Synaptophysin subsequently decreased until the adult level was reached by mid-adolescence, around age 16. PSD-95 levels increased postnatally to reach a stable plateau by early childhood with a slight reduction in late adolescence and early adulthood. The pattern of synaptophysin immunoreactivity seen with immunohistochemistry was similar to the Western experiments but the changes across age were more subtle, with little change by layer within and across age. The developmental patterns exhibited by these synaptic marker proteins expand upon previous studies of developmental synaptic changes in human frontal cortex; synaptic density increases steadily from birth to late childhood, then decreases in early adolescence to reach adult levels by late adolescence. Keywordsadolescence; development; human; synapses; pruning; synaptogenesisThe human brain has the most protracted period of development of any species, with neurodevelopment continuing well into early adulthood. Imaging studies have shown that in the human, the overall volume of the brain increases during childhood and adolescence (Giedd Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptNeuroscience. Author manuscript; available in PMC 2008 November 9. Sowell et al. 2002;Gilmore et al. 2007). Specifically, the cortical gray matter volume, particularly the f...

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Section: Discussionsupporting

confidence: 84%

Section: Discussionmentioning

confidence: 92%

Synaptophysin and postsynaptic density protein 95 in the human prefrontal cortex from mid-gestation into early adulthood

Glantz¹,

Gilmore²,

Hamer³

et al. 2007

Neuroscience

232

162

View full text Add to dashboard Cite

show abstract

“…[56][57][58][59] Correlation analysis showed no association between any of the NMDA receptor subunits and age with the exception of NR2C in DLPFC (r = 0.46, P = 0.03). In the ACC, only NR2B (r = 0.46, P = 0.04) was significantly associated with PMI.…”

Section: Resultsmentioning

confidence: 90%

Changes in NMDA receptor subunits and interacting PSD proteins in dorsolateral prefrontal and anterior cingulate cortex indicate abnormal regional expression in schizophrenia

et al. 2006

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Abnormal expression of the N-Methyl-D-Aspartate (NMDA) receptor and its interacting molecules of the postsynaptic density (PSD) are thought to be involved in the pathophysiology of schizophrenia. Frontal regions of neocortex including dorsolateral prefrontal (DLPFC) and anterior cingulate cortex (ACC) are essential for cognitive and behavioral functions that are affected in schizophrenia. In this study, we have measured protein expression of two alternatively spliced isoforms of the NR1 subunit (NR1 C2 and NR1 C2 0 ) as well as expression of the NR2A-D subunits of the NMDA receptor in DLPFC and ACC in post-mortem samples from elderly schizophrenic patients and a comparison group. We found significantly increased expression of NR1 C2 0 but not of NR1 C2 in ACC, suggesting altered NMDA receptor cell membrane expression in this cortical area. We did not find significant changes in the expression of either of the NR1 isoforms in DLPFC. We did not detect changes of any of the NR2 subunits studied in either cortical area. In addition, we studied expression of the NMDAinteracting PSD molecules NF-L, SAP102, PSD-95 and PSD-93 in ACC and DLPFC at both transcriptional and translational levels. We found significant changes in the expression of NF-L in DLPFC, and PSD-95 and PSD-93 in ACC; increased transcript expression was associated with decreased protein expression, suggesting abnormal translation and/or accelerated protein degradation of these molecules in schizophrenia. Our findings suggest abnormal regional processing of the NMDA receptor and its associated PSD molecules, possibly involving transcription, translation, trafficking and protein stability in cortical areas in schizophrenia.

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“…To begin to evaluate the effect of tissue quality markers on protein concentrations in the postmortem material, we measured protein concentrations in cerebellar tissue and correlated them with putative quality markers. Proteins of different sizes were chosen spanning different molecular weights (Rab 3A = 30 KDa; Syntaxin 1 = 35 KDa; Synaptotagmin 1 = 65 KDa; Munc-18 = 65 KDa) and from different cellular compartments (Rab 3A = 50% soluble, 50% synaptic vesicles; Syntaxin 1 = plasma membrane, Synaptotagmin 1 = synaptic vesicles, Munc-18 = 50% soluble, 50% plasma membrane) (Siew et al, 2004). These results were intended to be illustrative, not definitive.…”

Section: Correlates Of Tissue Qualitymentioning

confidence: 99%

Human postmortem tissue: What quality markers matter?

Ghose²,

et al. 2006

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Post mortem human brain tissue is used for the study of many different brain diseases. A key factor in conducting postmortem research is the quality of the tissue. Unlike animal tissue, whose condition at death can be controlled and influenced, human tissue can only be collected naturalistically. This introduces potential confounds, based both on pre-and postmortem conditions, that may influence the quality of tissue and its ability to yield accurate results. The traditionally recognized confounds that reduce tissue quality are agonal factors (e.g., coma, hypoxia, hyperpyrexia at the time of death), and long postmortem interval (PMI). We measured tissue quality parameters in over 100 postmortem cases collected from different sources and correlated them with RNA quality (as indicated by the RNA Integrity Number (RIN)) and with protein quality (as measured by the level of representative proteins). Our results show that the most sensible indicator of tissue quality is RIN and that there is a good correlation between RIN and the pH. No correlation developed between protein levels and the aforementioned factors. Moreover, even when RNA was degraded, the protein levels remained stable. However, these correlations did not prove true under all circumstances (e.g. thawed tissue, surgical tissue), that yielded unexpected quality indicators. These data also suggest that cases whose source was a Medical Examiner's office represent high tissue quality.

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

Cited by 50 publications

References 16 publications

Synaptophysin and postsynaptic density protein 95 in the human prefrontal cortex from mid-gestation into early adulthood

Synaptophysin and postsynaptic density protein 95 in the human prefrontal cortex from mid-gestation into early adulthood

Changes in NMDA receptor subunits and interacting PSD proteins in dorsolateral prefrontal and anterior cingulate cortex indicate abnormal regional expression in schizophrenia

Human postmortem tissue: What quality markers matter?

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