Chronic pain induced structural reorganization of spines in the anterior cingulate cortex

Abstract

Anterior cingulate cortex (ACC) has known to be involved in pain processing. Changes in spine number and morphology are some of the critical events during long-term synaptic plasticity. We induced chronic pain by neuropathic pain surgery and analyzed the change of dendritic spines after imaging single neuron in z-stack. Spine volumes, head diameters and straightness which reflected the overall structures of spines were not altered by chronic pain. Many other parameters of spines were also not altered by chronic pain, but only spine length, especially spine neck length decreased by chronic pain. Anisomycin treatment blocked chronic pain induced morphological changes of spines. From these results, we could conclude that chronic pain signal induced by nerve ligation in hind limb evoked structural plasticity of spines only in a minor level and it was related with protein synthesis.