1. Source: from Chinese Cobra Venom 2. Description: 3. Mol wt: 6,800~7,000 4. Identification of biological activity: (1) inhibitory functions in nerve-muscle synaptic transfer: assay in chick neck abdomen muscle nerve-muscle synaptic transfer shows that neurotoxin can inhibit nerve-muscle synaptic transfer with synaptic back theca as its function position. Inhibit functions are basically irreversible. Neurotoxin acts as postsynaptic neurotoxin. (2) abirritation: on mice, using hot plank. 5. Usage fields: (1) main application fields: A: Good specialty, strong appetency, can be used as probe in nerve transmitter receptor tissues and special position in cells. B: Can be used in the abruption and purification of special nerve transmitters. C: Good stability, with a variety of species and broad sources, easily crystallized, distinguished mode in relationship research between structure and effect. D: Strong immunity function with little mol wt, can be used in relationship research between antigen structure and immunity. E: Important tool in probe into transfer process of nerve signals and other nerve activities. (2) main clinic applications: A: Used in diagnoses of nerve disease such as myasthenia gravis in clinic B: Used in treatment of neuropathic headache and neuropathic sclerosis. C: Single or compound usage, can cure urgent toxicosis coma and other neuropathic diseases. D: Used in abnegating poison, killing pains without addiction. It has already been applied in abnegating poison for drudgers and the application dose could be reduced after it displays curative effect. At present, FDA has sanctioned producing two kinds of snake venom neurotoxins as medicines: one is Cobroxin, mainly curing obstinate neuralgia and malignant rumor pains; the other is Nyloxin, curing arthralgia.