Journal of molecular neuroscience : MN
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The activation of extracellular signal-regulated protein kinase (ERK) is essential for pain sensation and development of hyperalgesia in chronic pathological pain. Neonatal maternal separation (NMS) could trigger behavioral hyperalgesia and upregulate central neuronal activity in rats. The present study aims to investigate whether ERK associates with the colorectal distension (CRD)-evoked neuronal response and the upregulated central sensitivity to CRD in NMS rats. ⋯ Correlation analysis revealed the positive association between c-fos- and p-ERK-immunoreactive nuclei numbers in the DRG, lumbosacral dorsal horn, and ACC. These results demonstrate that ERK is actively involved in CRD-evoked neuronal activation in both NH and NMS rats. Moreover, ERK is associated with the upregulated central neuronal sensitivity to noxious CRD in NMS rats, which may be responsible for the behavioral hyperalgesia in NMS rat.