Brain tryptophan rather than pH-value is altered as consequence of artificial postmortem interval and storage conditions.

Brain bank centers around the world attempt to standardize postmortem brain collection and quality control. Antemortem as well postmortem factors may influence tissue quality. Previously, we could demonstrate that increased tryptophan (TRP) levels significantly correlate to prolonged postmortem interval (PMI) and storage duration, whereas pH-value altered merely as consequence of prolonged agonal state and ischemic brain damage additionally to repeated freeze and thaw cycles.

Methyl- and acetyltransferases are stable epigenetic markers postmortem.

Postmortem brain tissue has been reported to be suitable to delineate regional pattern of possible disturbances underlying epigenetic functionality. However, from many parameters that have been detected in postmortem brain regions it is noteworthy that an effect of postmortem interval (PMI), storage time and premortem parameters should not be underestimated. Our previous investigation revealed that tryptophan (TRP) levels in postmortem brain tissue is affected by PMI and storage time.

Tryptophan is a marker of human postmortem brain tissue quality.

Postmortem human brain tissue is widely used in neuroscience research, but use of tissue originating from different brain bank centers is considered inaccurate because of possible heterogeneity in sample quality. There is thus a need for well-characterized markers to assess the quality of postmortem brain tissue. Toward this aim, we determined tryptophan (TRP) concentrations, phosphofructokinase-1 and glutamate decarboxylase activities in 119 brain tissue samples.