Pain and hyperalgesia occured when L 5 and L 6 spinal nerves were ligated. To ev aluate the electrophysiological changes that contribute to this sensory patholog y, whole cell current clamp recording was performed in ...Pain and hyperalgesia occured when L 5 and L 6 spinal nerves were ligated. To ev aluate the electrophysiological changes that contribute to this sensory patholog y, whole cell current clamp recording was performed in DRGs that was obtained from neuropathic pain and control rats. After nerve ligation, action potential threshold reduced (more negative) in b oth small and median sized DRG neurons (-18.98±0.69 mV vs -11.12±1.06 mV in c ontrol small sized neurons; -19.44 ±2.22 mV vs -14.55±1.81 mV in control m edi an sized neurons), but resting membrane potential action potential duration at half amplitude (APD 1/2 ) and action potential amplitude did not change sign ifica ntly. In addition, obvious membrane potential oscillations were observed in smal l sized DRG neurons from neuropathic pain rats (P<0.05 compared with control group). These results suggested that neuropathic pain increased the exci tability of nociceptors, which may be an important mechanism underlying peripher al hypersensitivity.展开更多
AIM: To investigate proteomic changes in spinal cord and dorsal root ganglia (DRG) of rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. METHODS: The colonic myeloperoxidase (MPO) activity and tumor necro...AIM: To investigate proteomic changes in spinal cord and dorsal root ganglia (DRG) of rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. METHODS: The colonic myeloperoxidase (MPO) activity and tumor necrosis factor-(TNF- ) level were determined. A two-dimensional electrophoresis (2-DE)-based proteomic technique was used to profile the global protein expression changes in the DRG and spinal cord of the rats with acute colitis induced by intracolonic injection of TNBS. RESULTS: TNBS group showed significantly elevated colonic MPO activity and increased TNF-level. The proteins derived from lumbosacral enlargement of the spinal cord and DRG were resolved by 2-DE; and 26 and 19 proteins that displayed significantly different expression levels in the DRG and spinal cord were identified respectively. Altered proteins were found to be involved in a number of biological functions, such as inflammation/immunity, cell signaling, redox regulation, sulfate transport and cellular metabolism. The over-expression of the protein similar to potassium channel tetramerisation domain containing protein 12 (Kctd 12) and low expression of proteasome subunit type-1 (psma) were validated by Western blotting analysis. CONCLUSION: TNBS-induced colitis has a profound impact on protein profiling in the nervous system. This result helps understand the neurological pathogenesis of inflammatory bowel disease.展开更多
AIM:The localization of CB1 receptors in the spinal cord,spinal roots,dorsal root ganglion(DRG),and peripheral nerve of the rat was determined.METHODS:We studied the distribution of CB1 cannabinoid receptors by immuno...AIM:The localization of CB1 receptors in the spinal cord,spinal roots,dorsal root ganglion(DRG),and peripheral nerve of the rat was determined.METHODS:We studied the distribution of CB1 cannabinoid receptors by immunohistochemistry using an antibody raised against the N-terminal of the receptor.RESULTS:The spinal cord showed numerous transverse fibers labelled for CB1 receptors throughout and concentrated in the dorsal horn.Lightly-stained cells were observed throughout the spinal cord gray matter.The DRG also showed cells and fibers labelled for CB1 receptors.Labelled fibers were observed in both dorsal and ventral roots as well as in peripheral nerves.CONCLUSION:The presence of CB1 receptors in the DRG,the dorsal root,and the dorsal horn is in accordance with the analgesic effects of cannabinoids.The presence of labelled cells and fibers in the ventral horn and ventral root provides a substrate for cannabinoid-induced muscle relaxant and antispastic effects.展开更多
文摘Pain and hyperalgesia occured when L 5 and L 6 spinal nerves were ligated. To ev aluate the electrophysiological changes that contribute to this sensory patholog y, whole cell current clamp recording was performed in DRGs that was obtained from neuropathic pain and control rats. After nerve ligation, action potential threshold reduced (more negative) in b oth small and median sized DRG neurons (-18.98±0.69 mV vs -11.12±1.06 mV in c ontrol small sized neurons; -19.44 ±2.22 mV vs -14.55±1.81 mV in control m edi an sized neurons), but resting membrane potential action potential duration at half amplitude (APD 1/2 ) and action potential amplitude did not change sign ifica ntly. In addition, obvious membrane potential oscillations were observed in smal l sized DRG neurons from neuropathic pain rats (P<0.05 compared with control group). These results suggested that neuropathic pain increased the exci tability of nociceptors, which may be an important mechanism underlying peripher al hypersensitivity.
基金Supported by The Research Grants Council of Hong Kong,RGC-HKBU2/07CThe Hong Kong Jockey Club Institute of Chinese Medicine, JCICM4-07
文摘AIM: To investigate proteomic changes in spinal cord and dorsal root ganglia (DRG) of rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. METHODS: The colonic myeloperoxidase (MPO) activity and tumor necrosis factor-(TNF- ) level were determined. A two-dimensional electrophoresis (2-DE)-based proteomic technique was used to profile the global protein expression changes in the DRG and spinal cord of the rats with acute colitis induced by intracolonic injection of TNBS. RESULTS: TNBS group showed significantly elevated colonic MPO activity and increased TNF-level. The proteins derived from lumbosacral enlargement of the spinal cord and DRG were resolved by 2-DE; and 26 and 19 proteins that displayed significantly different expression levels in the DRG and spinal cord were identified respectively. Altered proteins were found to be involved in a number of biological functions, such as inflammation/immunity, cell signaling, redox regulation, sulfate transport and cellular metabolism. The over-expression of the protein similar to potassium channel tetramerisation domain containing protein 12 (Kctd 12) and low expression of proteasome subunit type-1 (psma) were validated by Western blotting analysis. CONCLUSION: TNBS-induced colitis has a profound impact on protein profiling in the nervous system. This result helps understand the neurological pathogenesis of inflammatory bowel disease.
文摘AIM:The localization of CB1 receptors in the spinal cord,spinal roots,dorsal root ganglion(DRG),and peripheral nerve of the rat was determined.METHODS:We studied the distribution of CB1 cannabinoid receptors by immunohistochemistry using an antibody raised against the N-terminal of the receptor.RESULTS:The spinal cord showed numerous transverse fibers labelled for CB1 receptors throughout and concentrated in the dorsal horn.Lightly-stained cells were observed throughout the spinal cord gray matter.The DRG also showed cells and fibers labelled for CB1 receptors.Labelled fibers were observed in both dorsal and ventral roots as well as in peripheral nerves.CONCLUSION:The presence of CB1 receptors in the DRG,the dorsal root,and the dorsal horn is in accordance with the analgesic effects of cannabinoids.The presence of labelled cells and fibers in the ventral horn and ventral root provides a substrate for cannabinoid-induced muscle relaxant and antispastic effects.
