Effect of melatonin on prefrontal cortex ischemia-induced cognitive impairment in rats and the receptor mechanism
10.3760/cma.j.cn131073.20210829.01225
- VernacularTitle:褪黑素对大鼠前额叶皮层缺血诱发认知功能障碍的影响及其受体机制
- Author:
Ying YUAN
1
;
Hong CHANG
;
Hongqiong YUAN
;
Congwen YANG
;
Kaizhi LU
;
Jinquan WANG
Author Information
1. 重庆市第九人民医院麻醉科 400700
- Keywords:
Prefrontal cortex;
Ischemia;
Melatonin;
Cognition disorders
- From:
Chinese Journal of Anesthesiology
2021;41(12):1514-1517
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the effect of melatonin on prefrontal cortex ischemia-induced cognitive impairment in rats and to investigate the receptor mechanism.Methods:Clean-grade adult male Sprague-Dawley rats, weighing 300 g, were selected, and a catheter was implanted into the prefrontal cortex.The experiment was performed in two parts.Experiment Ⅰ Twenty-four rats, in which catheters were successfully inserted into the prefrontal cortex, were assigned into 3 groups ( n=8 each) using a random number table method: control group (group C), model group (group M) and melatonin group (group ME). Normal saline 0.5 μl was injected into the prefrontal cortex in group C, 1 μmol/L endothelin 0.5 μl was microinjected into the prefrontal cortex in group M, and 1 μmol/L endothelin and 1 μmol/L melatonin 0.5 μl were injected into the prefrontal cortex in group ME.Experiment Ⅱ Forty-four rats, in which catheters were successfully inserted into the prefrontal cortex, were assigned into 4 groups ( n=11 each) using a random number table method: model group (group M), melatonin group (group ME), MT 1/2R antagonist luzindole + melatonin group (group L + ME) and MT 2R antagonist 4p-pdot + melatonin group (group P + ME). In group M, 1 μmol/l endothelin 0.5 μl was microinjected into the prefrontal cortex.In group ME, 1 μmol/L endothelin + 1 μmol/L melatonin 0.5 μl was injected into the prefrontal cortex.In group L + ME, 1 μmol/L endothelin + 1 μmol/L MT 1/2R antagonist + 1 μmol/L melatonin 0.5 μl was injected into the prefrontal cortex.In group P + ME, 1 μmol/L endothelin + 1 μmol/L MT 2R antagonist + 1 μmol/L melatonin 0.5 μl was injected into the prefrontal cortex.T-maze and the open field tests were performed at 1 week after administration. Results:Experiment Ⅰ There was no significant difference in the locomotor speed in open field test among C, M and ME groups ( P>0.05). The rate of correct selection in T-maze test was significantly lower in M and ME groups than in group C and higher in group ME than in group M( P<0.05). Experiment Ⅱ There was no significant difference in the locomotor speed in open field test among the four groups( P>0.05). Compared with group M, the rate of correct selection in open field test was significantly increased in ME and P+ ME groups ( P<0.05), and no significant change was found in group L+ ME ( P>0.05). Compared with group ME, the rate of correct selection in open field test was significantly decreased in group L+ ME ( P<0.05), and no significant change was found in group P+ ME( P>0.05). Conclusion:Melatonin can attenuate prefrontal cortex ischemia-induced cognitive impairment in the rats, and the mechanism is related to activation of MT 1R.
