The Characters Of Behaviors And Allodynia In The Mice Model Of Migraine And The Effect Of Sleep Deprivation On Allodynia

Part 1:Migraine-like behaviors in a dural electrical stimulation model of conscious micePurpose:Animal models can help us explore the pathology of the disease and search for new potential drug targets.Although great progress has been made in the animal models of migraine,currently no models can replicate all components of migraine.This research aimed to validate migraine-like behaviors,including nociceptive behavior,photophobia and avoidance of routine physical activity,in a newly established model in conscious mice and to determine whether these behaviors could be attenuated by pretreatment with sumatriptan.Method:The intensity of stimulation was established on the preliminary experiment.The intensity was confirmed by the Laser Speckle Contrast Analysis.Then,69 mice were randomly divided into three groups:sham/saline(injected with saline intraperitoneally and no dural electrical stimulation),stimulation/saline(injected with saline intraperitoneally and received dural electrical stimulation),and stimulation/sumatriptan(injected with sumatriptan intraperitoneally and received dural electrical stimulation).Wiping and scratching time,number of transitions and time spent in the light portion of the light/dark chamber,and travel distance during the stimulation were recorded.Results:According to the results of preliminary experiment and laser speckle contrast analysis,the intensity of 0.4mA/0.5Hz was selected.Compared to the sham/saline group,the mice in the stimulation/saline group spent more time wiping and scratching around the scalp and periorbital area made fewer transitions and spent less time in the light chamber,and traveled a shorter distance during the stimulation.Pretreatment with sumatriptan could attenuate all these behaviors to some extent.Conclusion:This study revealed that numerous migraine-like behaviors were present in our dural electrical stimulation model,which may provide more parameters for behavioral observation for drug research in the future.Part 2:The charters of a repetitive electrical stimulation mice model and topiramate treatment could prevents chronic sensitization induced by the repeated dural electrical stimulationPurpose:Chronic migraine brings great burden to patients.One of the bottlenecks restricting the development of new treatment methods for chronic migraine is the lack of effective predictive animal models.As a characteristic manifestation of migraine,the specific mechanism of allodynia remains still unclear.The aim of this study is to establish a chronic migraine model by repeated electrical stimulation of the dura mater in the superior sagittal sinus of conscious mice,and to explore the potential mechanism of pain sensitization and topiramate therapy in migraine.Method:Twenty-four mice were randomly divided into three groups:group 1:Sham-stimulation/saline;group 2:electrical stimulation/saline;group 3:electrical stimulation/sumatriptan.Von fery filaments were used to measure the mechanical pain threshold of the soles of the feet of mice after electrical stimulation/pseudo-stimulation,and the brain was perfused with anesthesia.Fos expression in the TNC region and upper cervical segment were analyzed.Thirty-two mice were randomly divided into four groups:group 1:sham stimulation/saline;group 2:electric stimulation/saline;group 3:electric stimulation/sulmatroptan;group 4:electric stimulation/topiramate group.After one week of recovery,four groups of mice were given intraperitoneal injection of saline,sulmatroptan or topiramate,respectively,the electrical stimulation was performed on the 1st,3rd,5th,7th and 9th days.The mechanical pain threshold of hind paw of mice was measured before the stimulation in these days.On the first day and the tenth day,the latency of the thermal pain threshold was measured by hot plate.After brushing the sole of the feet of mice with soft brush,the brain was perfused,the lumbar enlargement of spinal cord and brain tissue were taken.The Fos expression in the lumbar enlargement of spinal cord and RVM region were performed.Results:Compared with the sham-stimulation group,single electrical stimulation of the dura mater of mice caused a decrease in the mechanical pain threshold of hind paw sole and a large amount of Fos protein expression in TNC and upper cervical regions.Prior intraperitoneal injection of sumatriptan could effectively inhibit the decrease of mechanical pain threshold and the expression of Fos protein in TNC and upper cervical regions.Repeated electrical stimulation of dura mater could induce progressive decrease of mechanical pain threshold of hind paw sole in mice.Sumatriptan intraperitoneally injected every day could not inhibit the decrease of mechanical pain threshold.Topiramate daily could effectively inhibit the decrease of pain threshold of hind paw sole.For the latency of thermal pain threshold in the 10th day,electrical stimulation/topiramate group was significantly longer than that in the electric stimulation/saline group and the electric stimulation/sumatriptan group.Compared with stimulation/sumatriptan group,the increased Fos expression in the lumbar enlargement of spinal cord was present in stimulation/sumatriptan group and stimulation/saline group.The same results were obtained in Fos expression of RVM region.Conclusion:1.Single electrical stimulation of the dura mater in the superior sagittal sinus of conscious mice can mimic pain sensitization in acute migraine,and this effect can be inhibited by sumatriptan.2.Repeated electrical stimulation of the dura mater in the superior sagittal sinus of conscious mice can aggravate progressively pain sensitization.Sumatriptan injection daily can not inhibit the development of chronic pain sensitization,while topiramate can effectively inhibit chronic pain sensitization.3.Peripheral sensitization induced by electrical stimulation of dural model may be closely related to the regulation of RVM region.4.The therapeutic effect of topiramate may be related to the inhibition of sensitization of RVM neurons.Part 3 Acute sleep deprivation can significantly aggravate the pain sensitization induced by nitroglycerin in micePurpose:Sleep deprivation and migraine have become public health problems all around the world.Sleep deprivation can induce migraine,and migraine patients often like to rest in bed when they have a headache attack.Whether acute sleep deprivation can affect the degree and duration of headache?Based on nitroglycerin model in mice,this study was aimed to explore the effect of acute sleep deprivation on pain sensitization in mice.Methods:Part I:32 C57 mice were randomly divided into four groups:sleep deprivation/saline group,sleep deprivation/nitroglycerin group,non-sleep deprivation/nitroglycerin group,and non-sleep deprivation/saline group.After 6 hours of sleep deprivation or 6 hours of non-interference,four groups of mice were intraperitoneally injected with nitroglycerin or saline,Von-Frey filament and hot plate test,respectively.The mechanical thresholds and latency of thermal pain thresholds were measured for half an hour and lasted for 6 hours.Twenty-four mice were re-purchased and.Then they were sacrificed in batches 2 hours and 4.5 hours after intraperitoneal injection.TNC and upper cervical segments were taken for immunofluorescence Fos staining.The second part:Thirty-two mice were re-purchased and randomly divided into four groups:saline/sleep deprivation group,saline/sleep deprivation group,nitroglycerin/sleep deprivation group,nitroglycerin/sleep deprivation group.After intraperitoneal injection of saline or nitroglycerin,the mice were deprived of sleep for 6 hours or without interference.The mechanical pain threshold and thermal pain threshold latency were measured after 6 hours.Results:Sleep deprivation for 6 hours did not cause the changes in the baseline of mechanical pain threshold and thermal pain threshold in mice.Prior sleep deprivation significantly prolonged the duration of trough duration(i.e.the duration of minimum threshold duration)and the total duration of threshold decline caused by nitroglycerin.The expression of Fos in 2-hour TNC area and upper cervical segment in sleep deprivation/nitroglycerin group and non-sleep deprivation/nitroglycerin group was significantly higher than that in the other two groups,but there was no statistical difference between the two groups.The expression of Fos in 4.5 hours above brain area in sleep deprivation/nitroglycerin group was significantly higher than that in non-sleep deprivation/nitroglycerin group,and the difference was statistically significant.When intraperitoneal injection was given first,the mechanical pain threshold of hind paw in the nitroglycerin/sleep deprivation group was significantly lower than that in the other three groups.Conclusion:Acute sleep deprivation can significantly aggravate the allodynia induced by nitroglycerin in mice.