Characters of evoked burst and it’s current mechanism in CCD model
作者单位：Oregon Health Sciences UniversityBeavertonOR 97006USA
会议名称：《中国神经科学学会第四次会员代表大会暨第八届全国学术会议》
会议日期：2009年
学科分类：0710[理学-生物学] 07[理学] 071006[理学-神经生物学]
基 金：supported by the National Scientific Foundation of China(No.30530260 No.30870829)
关 键 词：neuropathic pain dorsal root ganglion mechanical allodynia pain signal periphery analgesia
摘 要：正Objective Lots of neuropathic pain models were made during decades of investigations,in which spontaneous discharge originated from dorsal root ganglion（DRG） were regarded as a key point for development of various abnormal pain *** idea of that if any firing patterns could be identified to be related to certain abnormal pain behavior has not been concerned up to *** present study is to explore what’s kind of characters of evoked burst（EB）,a newly observed firing pattern *** whether it is related to the mechanical allodynia exhibited on a chronic compression of DRG（CCD） model,which mimicking the clinical intervertebral foramen stenosis or proceeding of intervertebral disc. Methods On a CCD model,the von-Frey stimulation were used to observe the mechanical allodynia,in vivo sharpelectrode or in vitro patch-clamp recording were carried on to record the activity from DRG *** interruptions were applied to see the effect on EB as well as the underlying current ***（1） After CCD model,the DRG soma became hyperexcitable with various firing pattern.（2） On the animal with obvious mechanical allodynia,a kind of evoked burst（EB）,which means a periphery input spike followed by the somatic burst firing,was identified on Aβtype of neurons with a significantly increased percentage of 34%（15/44） comparing to those in normal（10%,1/9）,either at the resting membrane level or on a depolarized potential.（3） The EB has the following character:it’s exist relys on the complement of the periphery input,on the other words,it was evoked by periphery stimulation,either from electrical stimulation of the sciatic nerve or the stimulation of their natural receptive *** the shape of the first spike in the burst,the EB could be identified from those of spontaneous burst（SB）,namely,EB has a rapid-onset kinetics（with a rising speed of 50.75±6.46V/s,n=9） while SB has a prepotential phase at the foot of first spike（with a rising speed of 2.34±0.92V/