Morphometric analysis of neuronal and glial cell pathology in the dorsolateral prefrontal cortex in late-life depression.

BACKGROUND Late-life depression has been associated with cerebrovascular disease and especially with ischaemic white matter hyperintensities on magnetic resonance imaging. Neuroimaging and morphometric studies have identified abnormalities in the dorsolateral prefrontal cortex. AIMS To examine glial and neuronal density and neuronal volume in the dorsolateral prefrontal cortex in late-life major depression. METHOD We used the disector and nucleator methods to estimate neuronal density and volume and glial density of cells in the dorsolateral prefrontal cortex in a post-mortem study of 17 individuals with late-life major depression and 10 age-matched controls. RESULTS We found a reduction in the volume of pyramidal neurones in the whole cortex, which was also present in layer 3 and more markedly in layer 5. There were no comparable changes in non-pyramidal neurones and no glial differences. CONCLUSIONS Overall, we found a decrease in pyramidal neuronal size in the dorsolateral prefrontal cortex in late-life depression.