Work

A neural circuit from paratenial thalamic nucleus to anterior cingulate cortex for the regulation of opioid-induced hyperalgesia in male rats

Year: 2024

Type: article

Abstract: Prolonged use of opioids can lead to increased sensitivity to painful stimuli, a condition referred to as opioid-induced hyperalgesia (OIH). However, the mechanisms underlying this contradictory situation remain unclear. This study elucidates the pivotal role of the paratenial thalamic nucleus (PT)-anterior cingulate cortex (ACC) neuronal circuit in the development of OIH in male rats. Immunofluorescence and electrophysiology experiments demonstrated aberrant activation of PT glutamatergic neurons (PT Glu ) in rats with OIH. Optogenetic or chemogenetic activation of the PT Glu -ACC circuit aggravates mechanical and thermal hyperalgesia. Conversely, the inhibition of neuronal circuits showed analgesic effects. Additionally, PT Glu neurons project to both ACC pyramidal neurons and interneurons . Moreover, OIH affects the function of the ACC microcircuit, leading to decreased feedforward inhibition and an inhibitory/excitatory (I/E) imbalance in ACC pyramidal neurons. In conclusion, our findings highlighted the role of the PT Glu -ACC neuronal circuit in the development of opioid-induced hyperalgesia, suggesting that this circuit is a promising therapeutic target for addressing the side effects of opioids.

Source: Neurobiology of Disease

DOI: 10.1016/j.nbd.2024.106745