کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4331486 1614300 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Glycosylation-induced depolarization facilitates subthreshold membrane oscillation in injured primary sensory neurons
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
Glycosylation-induced depolarization facilitates subthreshold membrane oscillation in injured primary sensory neurons
چکیده انگلیسی

Subthreshold membrane potential oscillations (SMPO) in the injured dorsal root ganglion (DRG) neurons are involved in the generation of spontaneous activity, which can directly evoke neuropathic pain. Nerve injury usually triggers the synthesis of large quantities of membrane protein in nerve injured DRG neurons. Membrane proteins are glycosylated by addition of sugars, especially negatively charged sialic acid residues, which may depolarize the resting membrane potential (Vm), open voltage-gated channels in injured neurons, and cause spontaneous activity. In the present study, we aimed to determine if increased negative charge on the cell surface, carried by the sialic acid residues, could contribute to the generation of SMPO in injured DRG neurons. Intracellular recording was performed in DRG neurons following chronic constrictive injury (CCI) of the sciatic nerve. Results indicated that both A- and C-type injured DRG neurons exhibited a higher incidence of SMPO and more depolarized Vm than those of the control neurons. Ca2+, Mg2+, Mn2+, or poly-lysine, a positively charged organic compound, when topically applied to the DRG, not only reduced SMPO but also caused a rapid hyperpolarizing shift in Vm. Topical application of neuraminidase to selectively remove sialic acid residues on the extracellular membrane normalized the depolarized Vm and inhibited both spontaneous and evoked SMPO. However, application of Ca2+, Mg2+, Mn2+ or neuraminidase had no effect on excitability and Vm in normal neurons. The results demonstrated that the increase in negatively charged sialic acid residues on the extracellular membrane of neuronal somata is a critical factor in the generation of SMPO and hyperexcitability in injured sensory neurons.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Brain Research - Volume 1139, 30 March 2007, Pages 201–209
نویسندگان
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