Lipopolysaccharide-mediated inflammatory priming potentiates painful post-traumatic trigeminal neuropathy

Publication date: 1 October 2018Source: Physiology & Behavior, Volume 194Author(s): Yves Boucher, Nathan Moreau, Annie Mauborgne, Wisam DiebAbstractWe explored the molecular and behavioral effects of a perineural Lipopolysaccharide (LPS)-mediated inflammatory priming on the development and maintenance of painful post-traumatic trigeminal neuropathy (PPTTN) following infra-orbital nerve chronic constriction injury (CCI-IoN) in rats. Rats were pretreated with repetitive perineural injections in the vicinity of the IoN of either LPS or vehicle (Vhcl) before being submitted to CCI-IoN. Orofacial pain-like behaviors (response to Von Frey Filament testing and spontaneous isolated face grooming) were measured during the period of LPS injections (three weeks) and following CCI-IoN surgery (two weeks). Local LPS administration induced an early pain-like behavior (i.e. an increase in spontaneous pain [SP] or mechanical static allodynia [MSA]) in both conditions, and following CCI-IoN, MSA and SP developed earlier and more severely in LPS-pretreated rats than in the control group. Ipsilateral increases of key neuropathic pain mRNA markers in the IoN parenchyma, trigeminal ganglia (TG) and spinal trigeminal nucleus caudalis (Sp5C) were observed in CCI-IoN injured animals as compared to controls. Although no significant molecular differences could be observed within the IoN parenchyma between LPS and Vhcl-pretreated animals, a significant increase of key inflammatory cytokine Interleukin ...
Source: Physiology and Behavior - Category: Physiology Source Type: research