Trigeminal neuralgia is a manifestation of orofacial neuropathic pain disorder,always deemed to be an insurmountable peak in the field of pain research and treatment.The pain is recurrent,abrupt in onset and termination similar to an electric shock or described as shooting.A poor quality of life has been attributed to trigeminal neuralgia,as the paroxysms of pain may be triggered by innocuous stimuli on the face or inside the oral cavity,such as talking,washing face,chewing and brushing teeth in daily life.The pathogenesis of trigeminal neuralgia has not been fully elucidated,although the microvascular compression in the trigeminal root entry zone is generally considered to be involved in the emergence and progression of the pain disorder.In addition,orofacial neuropathic pain restricted to one or more divisions of the trigeminal nerve might be secondary to peripheral nerve injury.Based on current hypotheses regarding the potential causes,a variety of animal models have been designed to simulate the pathogenesis of trigeminal neuralgia,including models of compression applied to the trigeminal nerve root or trigeminal ganglion,chronic peripheral nerve injury,peripheral inflammatory pain and center-induced pain.However,it has not yet been possible to determine which model can be perfectly employed to explain the mechanisms.The selection of appropriate animal models is of great significance for the study of trigeminal neuralgia.Therefore,it is necessary to discuss the characteristics of the animal models in terms of animal strains,materials,operation methods and behavior observation,in order to gain insight into the research progress in animal models of trigeminal neuralgia.In the future,animal models that closely resemble the features of human trigeminal neuralgia pathogenesis need to be developed,with the aim of making valuable contributions to the relevant basic and translational medical research.

To establish a two-dimensional gel electrophoresis (2-DE) map for comparative proteomic analysis of rat spinal cord with chronic morphine tolerance, and to detect differentially expression proteins that are associated with chronic morphine tolerance.
 Methods: Sixteen male SD rats received the intrathecal catheterization operation and they were randomly divided into a morphine tolerance group (MT group, n=8) and a saline group (NS group, n=8). The lumbar enlargement segments of the MT group and the NS group spinal cord were harvested and proteins were separated by 2-DE. Differential proteome profiles were established and analyzed by means of immobilized pH gradient-based two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). The 2-DE maps were visualized after coomassie blue staining and analyzed using PDQuest analysis software. Identification of differential protein spots was conducted by MALDI-TOF-MS, and the Mascot query software was used to search Swiss-Prot database for bioinformatics analysis. Western blotting was used to verify the expression of some differentially expressed proteins.
 Results: A total of 1 000 spots were identified in 2-DE maps of rat spinal cord tissues from the MT group and the NS group, and 36 proteins were significantly differentially expressed in the MT group compared with the NS group. Identification was conducted by MALDI-TOF-MS and Swiss-Prot database through Mascot query software, and a total of 14 proteins were obtained. Among them, 2 protein spots were down-regulated in the MT group compared with that in the NS group, and 12 protein spots were up-regulated in the MT group compared with that in the NS group. Two kinds of proteins (NUDAA, ENOG) were verified by Western blotting and the results were consistent with proteomics data.
 Conclusion: The optimized 2-DE profiles for the proteome of spinal cord tissue in rats with chronic morphine tolerance is established preliminarily, which showed that morphine tolerance can cause changes in the expression of various proteins in the spinal cord.
Animals ; Electrophoresis, Gel, Two-Dimensional ; Male ; Morphine ; Proteome ; Proteomics ; Rats ; Rats, Sprague-Dawley ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Spinal Cord