Rat model of cancer-induced bone pain: changes in nonnociceptive sensory neurons in vivo

Autor: Yong Fang Zhu, Robert Ungard, Natalie Zacal, Jan D. Huizinga, James L. Henry, Gurmit Singh
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: PAIN Reports, Vol 2, Iss 4, p e603 (2017)
Druh dokumentu: article
ISSN: 2471-2531
00000000
81337418
DOI: 10.1097/PR9.0000000000000603
Popis: Abstract. Introduction:. Clinical data on cancer-induced bone pain (CIBP) suggest extensive changes in sensory function. In a previous investigation of an animal model of CIBP, we have observed that changes in intrinsic membrane properties and excitability of dorsal root ganglion (DRG) nociceptive neurons correspond to mechanical allodynia and hyperalgesia. Objectives:. To investigate the mechanisms underlying changes in nonnociceptive sensory neurons in this model, we have compared the electrophysiological properties of primary nonnociceptive sensory neurons at 2 weeks after CIBP model induction with properties in sham control animals. Methods:. Copenhagen rats were injected with 106 MAT-LyLu rat prostate cancer cells into the distal femur epiphysis to generate a model of CIBP. After von Frey tactile measurement of mechanical withdrawal thresholds, the animals were prepared for acute electrophysiological recordings of mechanically sensitive neurons in the DRG in vivo. Results:. The mechanical withdrawal threshold progressively decreased in CIBP model rats. At 2 weeks, the Aβ-fiber low-threshold mechanoreceptors (LTMs) in CIBP model rats exhibited a slowing of the dynamics of action potential (AP) genesis, including wider AP duration and lower AP amplitude compared with sham rats. Furthermore, enhanced excitability of Aβ-fiber LTM neurons was observed as an excitatory discharge in response to intracellular injection of depolarizing current into the soma. Conclusion:. After induction of the CIBP model, Aβ-fiber LTMs at >2 weeks but not
Databáze: Directory of Open Access Journals
Externí odkaz: