Effects Of Estrogen And Progesterone On Associative Learning And Memory

Objective: 1.Observe the effect of estrogen and progesterone on the maintenance and regression behavior of combined learning and memory in female mice.2.Using electrophysiological methods to explore the neural mechanism of memory maintenance and regression in the brain barrel cortex of female mice under the action of estrogen.Methods: 1.Associative learning and memory model: The same weight C57Thy1-YFP female mice were selected at 15 days of birth.Randomly divide mice into four groups,the control group(n = 14 animals),the estrogen group(estradiol)(n = 14),the progestin(progesterone)group(n = 14),and the combined group(estradiol + Progesterone)(n = 14).Multi-sensory simulated stimulators with beard stimulation and butyl acetate odor stimulation were used to jointly train mice.The frequency of the multi-sensory simulated stimulators was 5 Hz.Intraperitoneal injections are given half an hour before training everyday.Training 40 s each,five times a day,and two hours apart.After ten days of continuous training,the training was stopped for one week,and the combined training was repeated for one day after one week.The corresponding reagents were injected intraperitoneally at a fixed time everyday of the week during which the training was stopped.2.Behavioral experiments: After the model associative learning and memory model is established,the intraperitoneal injection is stopped.Each day,a multi-sensory simulated stimulator was used to train mice with a combination of 5 Hz beard stimulation and butyl acetate odor stimulation.At the end of each day of training,a high-definition video was used to capture a video of the beard swings induced by the butyl acetate smell of mice,and the frequency and angle of the beard swings of the mice were digitally presented using image analysis software.The T-maze experiment was used to detect the selection of butyl acetate odor in mice in different experimental groups.The right beard stimulation was given to each group at 10,17 and 18 days after the modeling was completed.For the selection of butyl acetate in the above experiments,high-definition video camera was used for the whole recording.3.Local field potential experiment: In the experiment,control group mice and estrogen group mice were selected to record local field potential signals.Each group was taken for 10 days,17 days and 18 days respectively.The left barrel cortex was selected.Localization was performed,and the barrel cortex was inserted using a motorized micromanipulator,and the 5HZ mechanical vibration stimulation and the olfactory stimulation of butyl acetate were separately recorded to record the signal of the field potential on the left barrel cortex.4.Statistical methods: Digitization of beard swing frequency was processed using Matlab and Fiji Image J,data analysis was performed using SPSS22.0,and chart drawing was performed using Graphpad Prism5.The experimental results were expressed as mean ± standard error.The t-test was used for comparison between experiments.One-way ANOVA or SNK-q test was used for the data of two or more groups.P <0.05,P <0.01,and P <0.001 were considered statistically significant.Results: 1.Behavioral results: 1.1 Compared with the control group,with the increase of training time in the first ten days of the estrogen,progesterone and combination medication groups,the frequency and angle of beard swinging increased significantly(P <0.001).1.2 After the seven-day amnesia training,compared with the frequency and angle of the beard swing of the mice on the tenth day,the frequency and angle of the beard swing of the four groups were significantly reduced;compared with the control group,the estrogen,progesterone and combination medication groups were smaller.The whisker frequency and angle of rat whiskers increased significantly(P <0.001);compared with estrogen and progesterone,the frequency of whisker swing did not increase significantly in the combination group(P> 0.05).1.3 After the joint training was given again,compared with the control group,the frequency and angle of beard swinging of the estrogen,progesterone and combination medication groups quickly recovered to the levels before the forgetfulness training,and the frequency and angle of beard swinging of mice increased significantly(P <0.001);while the combination group did not significantly increase the frequency of estrogen and progesterone beard swings(P> 0.05).2.Field potential experiment results:2.1 After ten days of joint training,electrodes were implanted in the barrel cortex of the mouse.When the mice were stimulated with beard stimulation(frequency 5HZ)and butyl acetate odor stimulation,the field potential signal was recorded: When given mechanical stimulation,the control group,estrogen group,progesterone group,and combination drug group appeared in the barrel cortex and recorded tactile and odor stimulus signals.Compared with the control group,the tactile and odor stimulus signals The signal was significantly enhanced,and the tactile stimulus signal was significantly higher than the odor stimulus signal.There was no statistical difference in the signal between the combined drug group and the estrogen and progesterone group.When given butyl acetate odor stimulation,the control group,estrogen group,progestin group,and combination drug group appeared in the barrel cortex and recorded tactile stimulus signals and odor stimulus signals,and compared with the control group,the tactile stimulus signals And the odor stimulus signal was significantly enhanced,while the odor stimulus signal was significantly higher than the tactile stimulus signal.There was no statistical difference in the signal of the combined drug group compared with the estrogen and progesterone groups.2.2 Seventeen days of joint training,the local electrical signals of mouse barrel cortex were recorded.The results are as follows: When given mechanical stimulation,the control group,estrogen group,progesterone group,and combination drug group appeared in the barrel cortex and recorded tactile and odor stimulus signals.Compared with the control group,the tactile and odor stimulus signals The signal was significantly enhanced,and the tactile stimulus signal was significantly higher than the odor stimulus signal.There was no statistical difference in the signal between the combined drug group and the estrogen and progesterone group.When given butyl acetate odor stimulation,the control group,estrogen group,progesterone group and combination drug group appeared in the barrel cortex and recorded tactile stimulation signals and odor stimulation signals.Compared with the control group,the tactile stimulation signals and there was no significant change in the odor stimulus signal,but the odor stimulus signal was significantly higher than the tactile stimulus signal.There was no statistical difference in the signal between the combined drug group and the estrogen and progesterone groups.Conclusion: 1.Estrogen and progesterone can enhance the joint learning and memory of female mice,and can delay the forgetting rate of joint learning and memory of female mice.2.Estrogen can enhance the function of barrel cortex neurons and increase the connection between barrel cortex and pear cortex.3.The combined medication group has little effect on enhancing the combined learning and memory of female mice and delaying the forgetting rate of the combined learning and memory of female mice.