Immature Dentate Gyrus: An Endophenotype of Neuropsychiatric Disorders

Figure 7

A schematic representation of the model of involvement of the iDG phenotype in psychiatric disorders. In psychiatric disorders, such as schizophrenia, bipolar disorder, and depression, multiple genetic and environmental factors could induce mild chronic inflammation. This could subsequently result in multiple endophenotypes in the brain, including iDG. Inflammation could induce alterations in neurogenesis [106, 107], mitochondrial dysfunction [108, 109], and oligodendrocyte dysfunction [110, 111]. Involvement of inflammation in induction of a hypoglutamatergic state or hyperdopaminergic state remains unclear. These possible endophenotypes may affect each other, which may, in turn, cause behavioral abnormalities in psychiatric patients. There may not be a single “principal” or “core” mechanism that underlies the behavioral symptom of psychiatric disorders. Indeed, a shared or preserved set of multiple endophenotypes, as a whole, may be the principal mechanisms of these disorders.