Abstract:
مقدمه: نتایج تحقیقات اخیر نشان داد که آموزش فضایی والدین پیش از لقاح منجر به بهبود حافظه فضایی فرزندان میشود. جالب است بدانید که این انتقال از پدران به فرزندان نر و از مادر به فرزندان ماده آنها رخ میدهد. با این حال، فرآیند یادگیری فضایی (حافظه کوتاه مدت و بلند مدت، تحکیم حافظه) متاثر از تجربیات والدین در فرزندان هنوز به طور کامل مورد بررسی قرار نگرفته است. براین اساس تحقیق حاضر با هدف بررسی دقیق و کوشش به کوشش اثرات یادگیری یک تکلیف فضایی توسط پدران پیش از لقاح بر فرآیند یادگیری و شکلگیری حافظه در فرزندان نر از طریق تحلیل عملکرد فرزندان نر پدران آموزش دیده (یا آموزش ندیده) در تکلیف ماز آبی موریس انجام گرفت. روش کار: در مطالعه حاضر، رتهای نر 8 هفتهای نژاد ویستار به دو گروه تمرین فضایی و بدون تمرین تقسیم شدند. گروه تمرین فضایی در 5 روز متوالی در پروتکل ماز آبی موریس شرکت کرد اما گروه بدون تمرین در هیچگونه برنامه آموزشی شرکت نکرد. پس از پایان پروتکل تمرین رتهای هر دو گروه با رتهای ماده بالغ وارد مرحله جفتگیری شدند. پس از تولد فرزندان از هر گروه 16 رت نر یک ماهه انتخاب و از طریق تکلیف ماز آبی موریس یادگیری و حافظه فضایی آنان مورد ارزیابی قرار گرفت. یافتهها: نتایج نشان داد که فرزندان نر پدران آموزش دیده به طور قابل توجهی زمان گریز کوتاهتر، سرعت شنا بالاتر و مسافت کلی شنا کردن کوتاهتری داشته و حافظه فضایی آنان نسبت به فرزندان نر پدران آموزش ندیده بهبود یافت. نتیجهگیری: این یافتهها نشان میدهد که تمرینات فضایی پدران پیش از لقاح، یادگیری فضایی و روند تحکیم حافظه فرزندان نر را تسهیل میکند و همچنین میتواند منجر به بهبود انگیزش فرزندان در دستیابی به اهداف شود.
Introduction: Lamarck’s idea of the ability for transferring memories acquired in the face of various environmental conditions through non-educational and non-genetic mechanisms to children has been greatly considered. Previous studies have shown that the environmental experiences of parents, such as the exposure to environmental toxins, educational behaviors, stress and fear may affect the phenotypes of several generations. the inheritance of epigenetic patterns including DNA methylation, histone modification, and non-coding RNA to living organisms allows the information related to the ancestral environment to be passed on to their offspring. Presently, the acquired traits related to the learning and memory capabilities are among the most important issues in the field of epigenetic transmission. Considering that methylation DNA, histone methylation and histone acetylation are three major epigenetic processes involved in the regulation of memory which leads modification of epigenetic patterns, and given the possibility of transmitting epigenetic symptoms from parents to offspring, it is anticipated that the phenotypes created in the learning process and memory formation in parents will be passed on to their children, which facilitates the learning process and memory formation of the offspring. Therefore, this study aimed at specifically analyzing whether Paternal learning of a spatial task before fertilization can impact on the process of spatial learning in the male offspring.
Methods: In the present study, Adult male (8 weeks old) were used at the beginning of the study. The first eight male rats were randomly divided into two groups: spatial memory training group (n=4) and control group (n=4). The rats participated in the spatial memory training group in the Morris water maze Protocol and the control group did not participate in any training. After the end of the training session, male rats of both groups mated with female rats that had not experienced any training. After the end of mating, pregnancy, birth and lactation, Four male offspring from each mother was randomly selected in each group and in the two groups paternal train (n=16) and paternal no-train (n=16) they were practicing Morris water maze within 5 days.
Results:
Escape latency
A two-way ANOVA with repeated measures (2×12) (Group × Trial) showed that the main effect of trials (F11, 330=19.63, p≤0.001), main effect of group (F11, 30=11.77, p≤0.01) and Interactive effect of trials and group (F111, 330=1.98, p≤0.032) is significant. The results of post-hoc test showed that in trials 5 there was a significant difference between the time to find the platform in the paternal train and paternal no-train groups, and male offspring of paternal train group had better performance.
Swimming speed
A two-way ANOVA with repeated measures (2×12) (Group × Trial) showed significant main effects of Trial (F (11, 330) = 7.48, p (1, 30) = 4.52, p (11, 330) = 0.69, p = 0.74) was not significant. The results showed that the swimming speed in the male offspring of trained fathers was higher than in the female offspring of not-trained fathers.
Total distance swum
A two-way ANOVA with repeated measures (2×12) (Group × Trial) showed significant main effects of Trial (F (11, 330) = 10.20, p (1, 30) = 7.14, p (11, 330) = 0.72, p = 0.71) was not significant. These data indicate that the total distance swum by the male offspring of trained fathers was significantly shorter than that of male offspring of not-trained fathers.
Probe phase
Twenty-four hours afterwards, the animals were submitted to the spatial probe test and the time spent in the target quadrant were calculated. Student’s t-test showed a significant difference between groups (t = 2.99, df = 30, p
Conclusion: These findings indicate that the paternal spatial training before fertilization improves the spatial learning and memory consolidation process and motivation of the male offspring.