Activation Of Extracellular Signal-Regulated Kinase (ERK) In Trigeminal Neuralgia

Objective:Injecting Penicillinum G-kalicum to Rat's cavitas subarachnoidealis and Chronic Constriction Injury to the Rat's lnfraorbital Nerve are two kinds of trigeminal neuralgia animal models. Horseradish peroxidase is used to retrograde trace spinal nucleus of trigeminal nerve. To investigate the role of ERK signal transduction pathway in trigeminal neuralgia, we apply ERK to trigeminal ganglion and spinal nucleus of trigeminal nerve in trigeminal neuralgia animal model, then detect the activation of ERK among these neurons. Our research will contribute to reveal the important role of ERK signal transduction pathway in trigeminal neuralgia pathogenesy.Method:â‘ Injecting Penicillinum G-kalicum to rat's cavitas subarachnoidealis to establish trigeminal neuralgia animal model.â‘¡Constriction Injury to the rat's infraorbital nerve to establish trigeminal neuralgia animal model.â‘¢Injecting horseradish peroxidase to the rat's infraorbital nerve to retrograde trace spinal nucleus of trigeminal nerve to oblongata and upper cervical cord,in order to trace the location of spinal nucleus of trigeminal nerve.â‘£Detect the activation of ERK in trigeminal ganglion and spinal nucleus of trigeminal nerve between TGN animal model group and control animal group of rats.Results:â‘ We observe the hyperalgia and allodynia reaction in both of TGN animal models. â‘¡After injecting HRP to infraorbital nerve, we find a great many deep blue neurons and primary afferent fibers which contain HRP particles. HRP is transport along primary afferent fiber center process to brain stem. Associate HRP staining with Nissl's staining, we have observed the neurons position and morphous of spinal nucleus of trigeminal nerve.â‘¢Immunohistochemistry and immunofluorescence techniques are applied to detect the activation of ERK in trigeminal ganglion and spinal nucleus of trigeminal nerve, we find that much phosphorylation of ERK in impair infraorbital nerve ipsolateral trigeminal ganglion and spinal nucleus of trigeminal nerve of TGN animal model rats, but there is no obviously express phosphorylation of ERK in opposite side and contol group rats.Conclusion:Both of injecting Penicillinum G-kalicum to Rat's cavitas subarachnoidealis and Chronic Constriction Injury to the Rat's lnfraorbital Nerve are two kinds of fine trigeminal neuralgia animal models,the former is fit for acute stage research in TGN,and the latter is more fit for long-term chronicity research in TGN. We can use horseradish peroxidase for tracing trigeminal nerves primary afferent sensory fibers.It can display trigeminal ganglion neurons, and is transported along primary afferent fiber center process to brain stem. Because pure HRP is unable to transport across to another neurone and can not show spinal nucleus of trigeminal nerve, we associate HRP staining with Nissl's staining in oblongata and upper cervical cord,then we can clearly observe neurons position and morphous of spinal nucleus of trigeminal nerve. ERK participates the conduction of pain sense, we find that a large mount of phosphorylation of ERK in rigeminal ganglion and spinal nucleus of trigeminal nerve. We conclude that ERK signal transduction pathway plays an essential role in TGN pathogenesis.