|Relations between cortical thickness, serotonin 1A receptor binding, and structural connectivity: A multimodal imaging study.
|Year of Publication
|Pillai RLI, Malhotra A, Rupert DD, Weschler B, Williams JC, Zhang M, Yang J, J Mann J, Oquendo MA, Parsey RV, DeLorenzo C
|Hum Brain Mapp
|Adult, Brain, Carbon Radioisotopes, Depressive Disorder, Major, Diffusion Tensor Imaging, Female, Humans, Magnetic Resonance Imaging, Male, Multimodal Imaging, Neural Pathways, Organ Size, Piperazines, Positron-Emission Tomography, Pyridines, Radiopharmaceuticals, Receptor, Serotonin, 5-HT1A
Serotonin 1A (5-HT ) receptors play a direct role in neuronal development, cell proliferation, and dendritic branching. We hypothesized that variability in 5-HT binding can affect cortical thickness, and may account for a subtype of major depressive disorder (MDD) in which both are altered. To evaluate this, we measured cortical thickness from structural magnetic resonance imaging (MRI) and 5-HT binding by positron emission tomography (PET) in an exploratory study. To examine a range of 5-HT binding and cortical thickness values, we recruited 25 healthy controls and 19 patients with MDD. We hypothesized increased 5-HT binding in the raphe nucleus (RN) would be negatively associated with cortical thickness due to reduced serotonergic transmission. Contrary to our hypothesis, raphe 5-HT binding was positively correlated with cortical thickness in right posterior cingulate cortex (PCC), a region implicated in the default mode network. Cortical thickness was also positively correlated with 5-HT in each cortical region. We further hypothesized that the strength of 5-HT -cortical thickness correlation depends on the number of axons between the raphe nucleus and each region. To explore this we related 5-HT -cortical thickness correlation coefficients to the number of tracts connecting that region and the raphe, as measured by diffusion tensor imaging (DTI) in an independent sample. The 5-HT -cortical thickness association correlated significantly with the number of tracts to each region, supporting our hypothesis. We posit a defect in the raphe may affect the PCC within the default mode network in MDD through serotonergic fibers, resulting in increased ruminative processing.
|Hum Brain Mapp
|PubMed Central ID
|K01 MH091354 / MH / NIMH NIH HHS / United States
R01 MH040695 / MH / NIMH NIH HHS / United States
P50 MH062185 / MH / NIMH NIH HHS / United States
R01 MH090276 / MH / NIMH NIH HHS / United States
F30 MH109412 / MH / NIMH NIH HHS / United States
R01 MH074813 / MH / NIMH NIH HHS / United States