| Although the peripheral nerve can regenerate in adult mammalian,the regenerative ability of peripheral nerve is very limited,because the average growth velocity of axon is about one millimeter a day, which is not enough for the need of injured peripheral nerve repair.So how to advance the growth velocity of axon has been focused on by many researchers in recent years. It is lucky that more and more neurotrophic factors have been found, which will bring bright future for many patients.However, with the development of research about neurotrophic factors, it had been gradually known that some difference and synergy existed among the different factors, even there were some disagreement about the same factor effects, Such as nerve growth factor (NGF) and ciliary neurotrophic factor (CNTF). The argument about NGF was focused on if it could not promote the peripheral nerve regeneration and about CNTF was whether it could selectively promote the regeneration of motor fibers. So it was very difficult to exactly compare and screen the effects of these factors and it must be resolved urgently in the research field of neuroscience at present. The traditionally research model of comparing the effects of different neurotrophic factors was the simple channel nerve conduit bridged the peripheral nerve defects in different animals. The function of some neurotrophic factors was compared through injecting different neurotrophic factors into the conduit.The experimental results were often affected by individual difference of animals , the simple channel nerve conduit also could induce serious responses to immunization, and these may affect the validity of research conclusion.The nerve chemotaxis induced by different neurotrophic factors could not be directly and dynamically observed in the simple channel nerve conduit.We first designed and manufactured the fusiform double channels nerve conduit(FDCNC) which was symmetrical to the middle axis and provided the same chance and environmental condition for the nerve regeneration. Then a new cabin for nerve regeneration was made after the medical chitosan jel was injected into both branch channels of FDCNC, which could gradually release neurotrophic factors.It had been verified that the new nerve regeneration cabin was scientific and precise to investigate the effects of different neurotrophic factors in vivo.FDCNC,which was injected NGF and CNTF into the both branch channels respectively ,was used to bridge the 10mm gap of sciatic nerve.The difference of myelinated fibres and unmyelinated fibres were studied with the HE, Holmes staining and electron microscope (EM) observation.The sensory and motor nerve fibres in the regenerative nerve were also discriminated and confirmed with immunohistochemistry technology. We not only evaluated the function of axoplasmic transport with the horseradish peroxidase (HRP) and nuclear yellow(NY) tracing,but also appraised the electrophysiological function by the test of the compound muscle action potentials (CMAP),cortical sematosensory evoked potential(CSEP) and motor nerve conduction velocity (MNCV). After comparing the different effects of NGF and CNTF, we also ivestigated the synergic effects on the nerve regeneratin. The major results and conclusions were as follows:1. The fusiform double channel nerve conduit(FDCNC) was designed and manufactured by ourselves , which is symmetrical to the middle axis, can provide the same chance and environmental condition for nerve regeneration,which is scientifically and feasibly in vivo.2. A new nerve regeneration cabin was made after the medical chitosan jel injected into the both branch channels of FDCNC, which could gradually release neurotrophic factors. It had been verified that the new nerve regeneration cabin could be used to not only scientifically and precisely study the biological effects of different neurotrophic factors, but also directly and dynamically observe the chemotaxis action in vivo.3.After comparing the different and synergic effects of NGF and CNTF on the chemotaxis action...
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