Effect Of Bruxism On GAT-1 In Amygdala And Prefrontal Cortex Of Stress Rats

Objective:To explore the effect of relieving pressure of bruxism by observing the behavior and the changes of ?-aminobutyric acid transporter-1(GAT-1)in amygdala and prefrontal cortex of rats with bruxism.Methods:1.Establishment of animal model: A total of 52 Sprague Dawley rats,weighing 280-300 g,were divided into control group(CO group),stress group(ST group)and bruxism group(SC group).The rats in ST group and SC group were placed in a fixed tube and bound for 30 minutes.At the same time,the rats in SC group were given a wooden stick with a diameter of 5 mm for chewing,and those chewed for less than 15 minutes were not used.CO group was fed regularly without any stimulation.2.Behavioral experiment: The rats were quickly placed in the center of the open box,the height of the box was 50 cm,the bottom of the box was 80 cm × 80 cm,which was divided into 16 squares of equal area,and the inner wall and bottom of the box were black.The scores of horizontal movement and vertical movement of rats in each group were recorded in 3 minutes,and the anxiety level was measured by the OF value of open-field test.3.Immunohistochemical staining: After the open-field test,18 rats(6 rats in each group)were randomly selected and killed immediately.The brain tissue was taken out and fixed,dehydrated,transparent,soaked in wax,embedded,sliced and made into sections.Then the GAT-1 immunohistochemical staining was performed.The amygdala and prefrontal cortex were cut off under the microscope.The average optical density of positive cells(AOD value)in each group was measured by Image J.4.Real-time quantitative PCR: After the open-field test,18 rats(6 rats in each group)were randomly selected and killed immediately.The amygdala and prefrontal cortex tissues were taken on the ice,and the total RNA in the tissues was extracted,RNA reverse transcripted into c DNA,PCR amplification was performed to detect the expression of GAT-1 m RNA in each group.Results:1.Behavioral experiment: Compared with CO group,the anxiety level of ST group was significantly increased;Compared with ST group,the anxiety level of SC group was significantly decreased,and there was no significant difference between SC group and CO group(P > 0.05)2.Immunohistochemical staining: Compared with CO group,the AOD value of amygdala and prefrontal cortex in ST group was significantly increased(P < 0.05);Compared with ST group,the AOD value of amygdala and prefrontal cortex in SC group was significantly decreased(P < 0.05),and there was no significant difference between SC group and CO group(P > 0.05).3.Real-time quantitative PCR: Compared with CO group,the expression of GAT-1 m RNA in amygdala and prefrontal cortex of ST group was significantly increased(P < 0.05);Compared with ST group,the expression of GAT-1 m RNA in amygdala and prefrontal cortex of SC group was significantly decreased(P < 0.05).Conclusion:1.Bruxism can relieve pressure.2.Bruxism can relieve the pressure by correcting the abnormal expression of GAT-1 to regulate the metabolism of GABA in amygdala and prefrontal cortex.