Effect of muscarinic acetylcholine receptor agonist on glycinergic spontaneous inhibitory postsynaptic currents and micro-inhibitory postsynaptic currents in spinal lamina Ⅱ neurons of rats
10.3760/cma.j.issn.0254-1416.2009.12.008
- VernacularTitle:M胆碱能受体激动剂对大鼠脊髓Ⅱ板层甘氨酸能神经元sIPSCs和mIPSCs的影响
- Author:
Xiuli WANG
;
Weidong MI
;
Yuexian GUO
- Publication Type:Journal Article
- Keywords:
Cholinergic agonists;
Receptors,cholinergic;
Glycine;
Spinal cord
- From:
Chinese Journal of Anesthesiology
2009;29(12):1087-1090
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of the mascarinic acetylcholine receptor (mAChR) agonist Oxo-tremorine-M (Oxo-M) on glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) and micro-inhibitory postaynaptic currents (mIPSCs) in lamina Ⅱ neurons in the spinal cord of rats. Methods Glycinergic IPSCs (sIPSCs and mIPSCs) in lamina Ⅱ neurons of spinal slices were recorded using the whole-cell voltage-clamp method. The non-selective mAchR ngonist Oxo-M was applied through bath perfusian. The effects of Oxo-M 1, 3, 5 and 10 μmol/L on sIPSCs and mIPSCs were examined. Results Oxo-M at the concentrations of 3-10 μmol/L significantly increased the frequency of sIPSCs without changing the amplitude in 16 lamina Ⅱ neurons tested. Interestingly, when the concentration of Oxo-M was increased to 10 μmol/L, the potentiating effect of Oxo-M on the frequency of slPSCs was decreased as compared with 3 μmol/L Oxo-M in the above 16 neurons. The slPSCs were completely abolished by 2 μmol/L strychnine. Atropine, the specific mAChR antagonist, completely blocked the effect of Oxo-M on the frequency of sIPSCs. In 9 additional lamina Ⅱ neurons, 1-10 μmol/L oxo-M failed to alter significantly the frequency and amplitude of glycinergic mIPSCs. Conclusion Activation of mAChRs in the somatodendritic site of glycinergic interneurous increases the synaptic glycine input to spinal dorsal horn neurons, but not in a dose-dependent manner.
