J Neurosci: revealing the molecular link between chronic pain and depression

October 19, 2019 / bioun / -- researchers at Hokkaido University have determined the brain mechanism between chronic pain and depression in mice Their research, recently published in the Journal of neuroscience, may lead to the development of new therapies for chronic pain and depression Professor masabumi Minami of Hokkaido University, one of the authors of the paper, said: "clinicians have long known that chronic pain often leads to depression, but the brain mechanism is not clear "Image source: J Neurosci researchers looked at how chronic pain affects neuronal pathways in mice They used an electrophysiological technique to measure the activity of neurons around chronic pain They found that persistent pain causes changes in neural pathways that project from areas of the brain called the nucleus of the striatum terminalis (BNST) to the ventral tegmental area (VTA) Specifically, they found that corticotropin releasing factor (CRF) - mediated signal enhancement, a known neuropeptide, is associated with negative emotions (such as anxiety and fear) in chronic pain animals Crucially, they found that this enhanced CRF signal leads to inhibition of the brain's reward system, a nervous system activated by reward, which is involved in the production of happiness and motivation Inhibition of the reward system is considered to be a potential mechanism of depression, which leads to a decrease in happiness and motivation "By clarifying the mechanism by which the brain reward system continues to be inhibited, we found a missing link between chronic pain and depression," Minami said The researchers found that when they treated mice with a drug that blocked excessive CRF signaling, dopamine neurons increased their activity, and they played an important role in the brain's reward system This suggests that drugs targeting neuropeptides such as CRF are expected to be used in the future to treat chronic pain and depression "These findings can not only improve the emotional aspects of chronic pain treatment, but also bring new treatments for depression," Minami said Reference materials: masabumi Minami et al Tonic pressure of the mosaic multipaminergic system by enhanced corporating relishing factor signaling within the bed nucleus of the strict terminations in chronic paint model rates The Journal of neuroscience, 2019; 3047-18 doi: 10.1523/junirosci.3047-18.2019