Such abnormalities in CBF and metabolism may reflect pathological changes in synaptic transmission associated with altered neurotransmitter receptor function, cerebrovascular disease, changes in neuronal arborization or synapse formation, or abnormalities in cellular viability or proliferation.5

For example, areas where CBF and metabolism appeared irreversibly decreased in depressives relative to controls in PET studies of MDD and BD were subsequently associated with focal tissue reductions in magnetic resonance imaging (MRI)-based morphometric and postmortem histopathological Inhibitors,research,lifescience,medical studies of MDD and BD.6-10 Figure 1 Summary of neuroimaging abnormalities in early-onset, primary, major depressive disorder (MDD). The regions where neurophysiological imaging abnormalities have been consistently reported in unmedicated MDD samples are listed and approximately shown on … Abnormalities of gray matter volume and histology have now been identified in several brain structures using volumetric MRI and postmortem neuropathological assessments, Inhibitors,research,lifescience,medical which in many cases were guided by initial application of functional imaging approaches. The regions affected by these abnormalities have been shown to play major roles in modulating Inhibitors,research,lifescience,medical emotional behavior by electrophysiological,

lesion analysis, and functional neuroimaging studies in experimental selleck chemicals animals and healthy humans. Thus, the structural abnormalities in these regions may prove relevant to the emotional dysregulation that is clinically manifest in mood disorders. Sensitivity for detecting

neuroimaging Inhibitors,research,lifescience,medical abnormalities in depression The neuroimaging abnormalities discovered to date have not had effect sizes sufficient to permit sensitive or specific classification of individual cases. Moreover, the psychiatric imaging literature is in disagreement regarding the specific location and Inhibitors,research,lifescience,medical direction of some abnormalities. Many limitations in the sensitivity in reproducing findings across studies appear to be accounted for simply by technical issues of image acquisition and/or analysis.1 In other cases, however, disagreements within the literature appear to reflect differences in subject selection criteria applied across studies, because the conditions encompassed by the diagnostic Oxymatrine criteria for MDD appear to be heterogeneous with respect to pathophysiology and etiology. It is noteworthy that neuroimaging laboratories selecting depressed subjects according to MDD criteria alone have rarely been able to replicate their own previous findings in independent subject samples. Instead, neuroimaging abnormalities appear to be specific to subsets of MDD subjects.1 For example, requiring that subjects have familial aggregation of illness and an early age at illness onset improved sensitivity for identifying subject samples with reproducible neuroimaging abnormalities.