Neurite orientation dispersion and density imaging reveals brain microstructure alterations associated with hyperalgesia and emotional disorders in neuropathic
Emotional disorders such as depression that accompany neuropathic pain (NP) impair the patient's quality of life and cause hyperalgesia through the brain nuclei network called the pain matrix. Structural alteration in the pain matrix is an essential mechanism for the co-morbidity and the mutual regulation of hyperalgesia and emotional disorders in NP, yet microstructural alterations such as neurite characteristics remain unclear. Neurite orientation dispersion and density imaging (NODDI) is a magnetic resonance imaging (MRI) that can detect the microstructure alterations of the brain nucleus. Here, in the NP mouse model with emotional disorders, we detected microstructural alterations in the nuclei of pain matrix by NODDI. The results showed a decrease of neurite density index (NDI) and orientation dispersion index (ODI) in the anterior cingulate cortex layers 5-6 of CCI mice, which were related to hyperalgesia and depression-like behavior. We also found an increase of ODI in the ventral posterolateral and paraventricular nucleus of the thalamus and an increase of NDI in the central amygdala. These results may serve as a new addition to clinical diagnosis and mechanism research of NP.
National Natural Science Foundation of China
82271204, 81771138 to Han Lu
Shanghai Municipal Health Commission
202040017 to Rong Dong