Spatiotemporal Dynamics of Brain Function During the Natural Course in a Dental Pulp Injury Model

Purpose: Toothache, a common disorder afflicting most people, shows distinct features at different clinical stages. This study aimed to depict metabolic changes in brain and investigate the potential mechanism involved in the aberrant affective behaviors during the natural process of toothache. Methods: We investigated the spatiotemporal patterns of brain function during the natural course of toothache in a rat model of dental pulp injury (DPI) by using positron emission tomography (PET). Results: Glucose metabolism peaked on the 3 rd day and gradually decreased in several brain regions after DPI, which was in line with the behavioral and histological results. PET imaging showed visual pathway was involved in the regulation of toothache. Meanwhile, the process of emotional regulation underlying toothache was mediated by N-methyl-D-aspartic receptor subunit 2B (NR2B) in the caudal anterior cingulate cortex (cACC). Conclusion: Our results revealed the spatiotemporal neurofunctional patterns during toothache process and preliminarily elucidated the role of NR2B in cACC in the regulation of toothache-related affective behaviors.