Pain is essential for our survival because it functions as a biological alarm for impeding or actual tissue damage. However, chronic pain is a persistent, inescapable stress, which leads to maladaptive emotional states.
Studies have reported depression and anxiety-like behaviors in animal models of chronic pain, which suggest that it causes plastic changes in neural circuits and gives rise to negative emotions, such as depression and anxiety.
In a recently published study, researchers from Hokkaido University have shown how chronic pain leads to maladaptive anxiety in mice, with implications for the treatment of chronic pain-related psychiatric disorders in humans. The study appears in the journal Science Advances.
Neuronal Pathway Could be Targeted for New Therapies
The study looked at how neuronal circuits are affected by chronic pain in a mice model using an electrophysiological technique to measure the activity of neurons after 4 weeks of chronic pain.
The team found that chronic pain caused neuroplastic changes that caused a suppression of the bed nucleus of the stria terminalis (BNST –a neuronal pathway projection from the brain– to the lateral hypothalamus.
They also found that by suppressing the activity of this pathway they were able to attenuate the chronic pain-induced anxiety, which could be further studied and lead to improved treatment of chronic pain, while also helping to develop new therapies for anxiety disorders.
Naoki Yamauchi, Keiichiro Sato, Kenta Sato, Shunsaku Murakawa, Yumi Hamasaki, Hiroshi Nomura, Taiju Amano, Masabumi Minami. Chronic pain–induced neuronal plasticity in the bed nucleus of the stria terminalis causes maladaptive anxiety. Science Advances, 2022; 8 (17) DOI: 10.1126/sciadv.abj5586