A role of NMDA receptor on stress related behavioral alternation in rats

[Speaker] Ji-Hye Park:1,3
[Co-author] Yong Cheon Na:2, Chang Yeob Han:3, Mi Jeong Han:3, Seong Bin Park:4, Seoul Lee:1,3
1:Wonkwang Brain Research Institute, Korea, 2:Wonkwang medical Institute, Korea, 3:Wonkwang University School of Medicine, Korea, 4:Korea Human Resource Development Institute for Health & Welfare, Korea

Environmental stress can induce to change of neurobehavioral function and neuropathy in the brain. Stress cause from environment can produce to various diseases as anxious, depressive and cognitive behaviors. The purpose of this study is behavioral alterations caused by environmental stress and enrichment were changed by glutamate receptor activity in the frontal cortices in the rat brain. 8 weeks-old Sprague-Dawley male rats were subjected to both Control group, the restraint stressed (Stressed) and enriched environment (Enriched) paradigm and treatment with MK-801, an NMDA receptor antagonist, for four hours of daily on seven consecutive days. All animals received food and water ad libitum except during exposure sessions. After the stimulation session, we evaluated a cognitive and behavioral function via morris water maze task, the Stress+D group was marked the delayed acquisition than others. But any difference cloud not found at the probe test. Exploratory behavior was measured for 3 min after exposure to a novel environment, the Stressed group showed a significantly increased ambulatory activity compare to the Enriched group. However, rats treated with MK-801 were arrested an anxiety-like behavior after exposure to a novel environment. So, both group of pretreatments of MK-801 animals were abolished those behavioral changed patterns induced by exposure to different environmental conditions. Rats were sacrificed after behavioral experiment and removed out of brains and we were searched the group 1 metabotopic glutamate receptor expression in the frontal cortex of brain. The mGlu-R1 and mGlu-R5 expressions were decreased both treated with MK-801 brains. The treatment of MK-801 within the environmental stimuli paradigm, which can cause difference of group 1 mGlu-R expression and it resulted to behavioral alterations. These results suggested that the mGlu-Rs activities in the frontal cortices a specific role in the awareness and cognition of the environmental stimulation as stress and stressor in emotional and behavioral brain functions. This research supported by National Research Foundation of Korea in 2017R1D1A3B03031448
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