To measure the entire volume, the exact borders of the studied region have to be establish ed,82,83 so that sampling is confined to the region within these borders. Unfortunately, in most studies of mood SGC-CBP30 nmr disorders in postmortem tissue, limited availability of the complete tissue region, as well as limitations in reliably distinguishing cytoarchitectonic borders of a studied region, have prevented the estimation of a total tissue volume and, consequently, total cell number. In one study where the total cell number was estimated in the subgenual cortex,
a loss of glial but not neuronal cells has been demonstrated in familial mood disorders.1 Glial reductions reported in this study may Inhibitors,research,lifescience,medical in fact reflect a true loss of glial cells since the neuroimaging studies in the same cortical region show a reduction in the volume of gray matter.84 There are unquestionable limitations to the use of postmortem brain tissue in studying the mood disorders.56 Some
of the critical issues to be considered when interpreting Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical the studies of postmortem brain tissue include the psychiatric status of the subject at the time of death and the underlying psychiatric disorder, whether “control” subjects were psychiatrically normal, the cause of death of the subjects (suicide or by other means), evolving criteria used to establish psychiatric diagnoses, the possible Inhibitors,research,lifescience,medical inclusion of subjects with concurrent psychoactive substance use disorders, the regional and hemispheric localization of the brain regions being studied, and the presence and duration of treatment with a psychotropic medication. Other frequent drawbacks to studies of postmortem brain tissue include low numbers of subjects per cohort, or inadequate expertise in cytoarchitectonic delineation of individual brain regions. Ideally, longitudinal clinical studies on wellcharacterized patients should be linked to subsequent postmortem
studies Inhibitors,research,lifescience,medical of the same subjects. It is important to seek to control for the potential effects of suicide on postmortem biological observations in depression. In two of our studies,5,36 enough depressed nonsuicide subjects were available to tentatively determine that the main findings of these studies appear to persist regardless of whether the depressed subjects died by suicide or natural causes. While suicide makes SB-3CT tissues available for most postmortem studies of depression, the results obtained with this cohort must be cautiously interpreted since the majority of living individuals with depression do not attempt or commit suicide. In the mood disorders, the alterations in cell density and size are likely to be related to the disorder itself and not to the age of subjects at the time of death, postmortem delay, or the time of fixation of the tissue.