Effect of occlusal interferences on dopamine release of prefrontal cortex in rats

Research Project

Project/Area Number	12671915
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	補綴理工系歯学
Research Institution	Osaka Dental University
Principal Investigator	INOUE Hiroshi Osaka Dental University, Dentistry, Professor, 歯学部, 教授 (30067053)
Co-Investigator(Kenkyū-buntansha)	KUREMOTO Koichi Osaka Dental University, Dentistry, Lecturer, 歯学部, 助手 (90319583) UEDA Yutaka Osaka Dental University, Dentistry, Professor, 歯学部, 教授 (10067001)
Project Period (FY)	2000 – 2001
Project Status	Completed (Fiscal Year 2001)
Budget Amount *help	¥3,100,000 (Direct Cost: ¥3,100,000) Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 2000: ¥2,600,000 (Direct Cost: ¥2,600,000)
Keywords	occlusal interference / dopamine / microdialysis method / stress / feeding / benzodiazepine / prefrontal cortex / rat / 情動
Research Abstract	We measured dopamine release from the prefrontal cortex of rats with occlusal interferences in order to clarify the relation between the occlusal interferences and psychiatric stress. Changes in the activity of the dopaminergic neuron system of the prefrontal cortex have been found to be an index of stress responses involved in anxiety and so on. We used benzodiazepine (diazepam) in this experiment to show whether increased dopamine release was caused by psychiatric stress. Dopamine release was measured using microdialysis in three experiments. In each experiment, a control group comprised 6 rats and an occlusal interference group comprised 6 rats. The level of dopamine release was measured for each experiment : We measured it before and after feeding pellets in experiment 1. Diazepam was intraperitoneally administered before the rats were fed pellets in experiment 2. Physiological saline was given to the rats before they Were fed pellets in experiment 3. Experiment 1: In the occlusal interference group only, the amount of dopamine release significantly increased after feeding, Experiment 2 : The amount of dopamine release did not significantly increase in either group. Experiment 3 : In the occlusal interference group only, the amount of dopamine release significantly increased after feeding. The amount of dopamine release increased by occlusal interference when rats had been fed. Diazepam suppressed this increase, but physiological saline did not. These results proved statistically that occlusal interferences related to psychiatric stress involved in anxiety.