Similarly, the premortem period can affect the number of certain messenger RNAs (Barton, et al., 1993). A number of studies report that RNA degradation correlates with such parameters as the environment and the circumstances of death. Thus, in typically developing/functioning organisms such factors as trauma, alcohol, and drug abuse, along with others, may cause changes in gene expression patterns (Heinrich, et al., 2007). Premortem hypoxia, coma and prolonged agony are also known to be linked to significant RNA degradation in postmortem brain tissue (Barton, et al., 1993; Mexal, et al., 2006). One of the mechanisms found to affect the pre- and postmortem factors listed above on RNA degradation is the reduction in the pH (an indicator of acidity) of the brain tissue (Barton, et al., 1993; Mexal, et al., 2006).
