Dynamic Changes of the Infralimbic Cortex and Its Regulation of the Prelimbic Cortex in Rats with Chronic Inflammatory Pain
Longyu Ma1 · Lupeng Yue2,3 · Shuting Liu1 · Yu Zhang1,4 · Meng Zhang1,5 · Shuang Cui1 · Feng‑Yu Liu1 · Ming Yi1,6 · You Wan1,6,71 Department of Neurobiology, School of Basic Medical Sciences, Neuroscience Research Institute, Peking University, Beijing 100083, China
2 CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing 100101, China
3 Department of Psychology, University of Chinese Academy of Science, Beijing 100101, China
4 NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, CAMS & PUMC, Beijing 100021, China
5 Department of Pathology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing 100045, China
6 Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100083, China
7 Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
Abstract
The prelimbic cortex (PL) is actively engaged in pain modulation. The infralimbic cortex (IL) has been reported to regulate the PL. However, how this regulation affects pain remains unclear. In the present study, we recorded temporary hyper-activity of PL pyramidal neurons responding to nociceptive stimuli, but a temporary hypo-function of the IL by in vivo electrophysiological recording in rats with peripheral inflammation. Manipulation of the PL or IL had opposite effects on thermal hyperalgesia. Furthermore, the functional connectivity and chemogenetic regulation between the subregions indicated an inhibitory influence of the IL on the PL. Activation of the pathway from the IL to the PL alleviated thermal hyperalgesia, whereas its inhibition exacerbated chronic pain. Overall, our results suggest a new mechanism underlying the role of the medial prefrontal cortex in chronic pain: hypo-function of the IL leads to hyperactivity of the PL, which regulates thermal hyperalgesia, and thus contributes to the chronicity of pain.
Keywords
Prefrontal cortex; Prelimbic cortex; Infralimbic cortex; Inhibitory regulation; Chronic pain
