Peripheral neuropathic pain is often difficult to be adequately treated in current medicine.Animal models may provide pivotal systems for preclinical study of pain.Partial spinal ligation,chronic constriction injury,and L5/L6 spinal nerve ligation represent three of the best characteristic rodent models of peripheral neuropathy.Recently,primary or permanent cultures of sensory neurons have been established to study the molecular mechanism of pain,especially for neurotransmitter release and signal transduction.