ACC glia and pyramidal neuron alterations in mood disorder patients
MedWire News: Results from a UK study show alterations in the anterior cingulate cortex (ACC) among patients with mood disorders.
"The ACC is a key region for the pathophysiology and treatment of depression," write Paul Harrison and Rebecca Gittins, from the University of Oxford, in the Journal of Affective Disorders.
"However, it remains unclear whether and how the morphology of the ACC is altered in subjects with mood disorders," they add.
To investigate further, the team studied postmortem supragenual ACC (Brodmann area 24b) tissue samples collected from seven patients with mood disorders, comprising five with major depressive disorder and two with bipolar disorder, and nine mentally healthy individuals (controls). The patients were aged a mean of 64.6 and 58.3 years, respectively, at the time of death.
The researchers measured cortical and layer depths using a microcator, and within each layer, glia and neuronal density, shape, and size were assessed. They also used immunoautoradiography to assess levels of the astroglial marker glial fibrillary acidic protein (GFAP).
The team found that there were no significant differences between the two groups regarding cortical and layer thickness.
However, the density of glial cells was 13-24% lower across all layers, except the Vb layer, in mood disorder patients compared with controls.
After accounting for brain pH, the researchers found that GFAP levels in white matter were reduced by around 30% in mood disorder patients compared with controls, with similar but nonsignificant reductions observed in gray matter.
They also found that the density of pyramidal neurons among mood disorder patients was decreased by 18% in layer Vb, while their size was increased by around 25% in layers V and VI, compared with controls.
In addition, the shape of pyramidal neurons differed in layers Va and VI among mood disorder patients compared with controls.
Harrison and Gittins conclude: "These data provide further evidence for morphometric alterations in glia and pyramidal neurons in mood disorder.
"They represent a possible cellular basis for the aberrant functioning and connectivity of the ACC apparent from neuroimaging and other studies."
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By Mark Cowen