Peripheral axotomy induces only very limited sprouting of coarse myelinated afferents into inner lamina II of rat spinal cord

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	Peripheral axotomy induces only very limited sprouting of coarse myelinated afferents into inner lamina II of rat spinal cord
	Zhang, X
刊名	EUROPEAN JOURNAL OF NEUROSCIENCE
	2002
卷号	16 期号:2 页码:175-185
关键词	plasticity dorsal root ganglion neuropeptide Y neuropeptide Y receptor pain ROOT GANGLION NEURONS SUPERFICIAL DORSAL HORN WHEAT-GERM-AGGLUTININ CHOLERAGENOID-HORSERADISH-PEROXIDASE PRIMARY SENSORY NEURONS C-FOS EXPRESSION IMMUNOREACTIVE-NEUROPEPTIDE-Y INTESTINAL POLYPEPTIDE VIP NERVE GROWTH-FACTOR SCIATIC-NERVE
ISSN号	0953-816X
通讯作者	Zhang, X (reprint author), Chinese Acad Sci, Shanghai Inst Biol Sci, Inst Neurosci, Lab Sensory Syst, Shanghai 200031, Peoples R China,
英文摘要	Peripheral axotomy-induced sprouting of thick myelinated afferents (A-fibers) from laminae III-IV into laminae I-II of the spinal cord is a well-established hypothesis for the structural basis of neuropathic pain. However, we show here that the cholera toxin B subunit (CTB), a neuronal tracer used to demonstrate the sprouting of A-fibers in several earlier studies, also labels unmyelinated afferents (C-fibers) in lamina II and thin myelinated afferents in lamina I, when applied after peripheral nerve transection. The lamina II afferents also contained vasoactive intestinal polypeptide and galanin, two neuropeptides mainly expressed in small dorsal root ganglion (DRG) neurons and C-fibers. In an attempt to label large DRG neurons and A-fibers selectively, CTB was applied four days before axotomy (pre-injury-labelling), and sprouting was monitored after axotomy. We found that only a small number of A-fibers sprouted into inner lamina II, a region normally innervated by C-fibers, but not into outer lamina II or lamina I. Such sprouts made synaptic contact with dendrites in inner lamina II. Neuropeptide Y (NPY) was found in these sprouts in inner lamina II, an area very rich in Y1 receptor-positive processes. These results suggest that axotomy-induced sprouting from deeper to superficial layers is much less pronounced than previously assumed, in fact it is only marginal. This limited reorganization involves large NPY immunoreactive DRG neurons sprouting into the Y1 receptor-rich inner lamina II. Even if quantitatively small, it cannot be excluded that this represents a functional circuitry involved in neuropathic pain.
学科主题	Neurosciences & Neurology
收录类别	SCI
语种	英语
公开日期	2012-07-23
内容类型	期刊论文
源URL	[http://ir.sibs.ac.cn/handle/331001/2050]
专题	上海神经科学研究所_神经所(总) 上海神经科学研究所_感觉系统研究组
推荐引用方式 GB/T 7714	Zhang, X. Peripheral axotomy induces only very limited sprouting of coarse myelinated afferents into inner lamina II of rat spinal cord[J]. EUROPEAN JOURNAL OF NEUROSCIENCE,2002,16(2):175-185.
APA	Zhang, X.(2002).Peripheral axotomy induces only very limited sprouting of coarse myelinated afferents into inner lamina II of rat spinal cord.EUROPEAN JOURNAL OF NEUROSCIENCE,16(2),175-185.
MLA	Zhang, X."Peripheral axotomy induces only very limited sprouting of coarse myelinated afferents into inner lamina II of rat spinal cord".EUROPEAN JOURNAL OF NEUROSCIENCE 16.2(2002):175-185.