اثرات بین ‌نسلی تمرین فضایی پدران پیش از لقاح بر فرآیند یادگیری فضایی و انگیزش فرزندان نر

مقدمه: نتایج پژوهش‌ های اخیر نشان داده است که آموزش فضایی والدین پیش از لقاح منجر به بهبود حافظه فضایی فرزندان می‌شود. اما، فرآیند یادگیری متاثر از تجربیات والدین در فرزندان مورد بررسی قرار نگرفته است. لذا 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 هیچ گونه 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 یافته بود. 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.

Intergenerational effects of paternal spatial training before fertilization on the spatial learning process and motivation in male offspring

Introduction: Lamarck rsquo;s idea of the ability to transfer memories acquired in the face of various environmental conditions through noneducational and nongenetic mechanisms to children has been extensively considered. Previous studies have shown that parents rsquo; environmental experiences, such as exposure to environmental toxins, educational behaviors, stress, and fear, may affect several generations rsquo; phenotypes. The inheritance of epigenetic patterns, including DNA methylation, histone modification, and noncoding 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 learning and memory capabilities are among the essential 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 to 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. It 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 the process of spatial learning in the male offspring.Methods: In the present study, Wistar adult male rats (8 weeks old) were used at the beginning of the study. The first eight male rats were randomly divided into the 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 were randomly selected in each group, and in the two groups, paternal train (n=16), and paternal notrain (n=16) they were practicing Morris water maze within five days.Results: Escape latency: A twoway ANOVA with repeated measures (2 ×12) (Group × Trial) showed that the main effect of trials (F11, 330=19.63, P le;0.001), the main effect of group (F11, 30=11.77, P le;0.01), and interactive effect of trials and group (F111, 330=1.98, P le;0.032) is significant. The posthoc test results revealed that in trial five, there was a significant difference between the time to find the platform in the paternal train and paternal notrain groups, and male offspring of the paternal train group had better performance than others. Swimming speed: A twoway ANOVA with repeated measures (2 ×12) (Group ×Trial) showed significant main effects of Trial (F(11, 330)=7.48, P<0.01) and Group (F(1, 30)=4.52, P<0.05), while the interaction Group ×Trial (F(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 nottrained fathers. Total distance swum: A twoway ANOVA with repeated measures (2 ×12) (Group ×Trial) showed significant main effects of Trial (F(11, 330)=10.20, P<0.001) and Group (F(1, 30)=7.14, P<0.05), while the interaction Group ×Trial (F(11, 330)=0.72, P=0.71) was not significant. These data indicate that the male offspring of trained fathers rsquo; total distance swum was significantly shorter than that of male offspring of nottrained fathers. Probe phase: Twentyfour hours afterward, the animals were submitted to the spatial probe test, and the time spent in the target quadrant was calculated. Student rsquo;s ttest showed a significant difference between groups (t=2.99, df=30, P<0.01). The results showed the longer time spent in the target quadrant displayed by the male offspring of trained fathers compared to the male offspring of nottrained fathers.Conclusion: These findings indicate that paternal spatial training before fertilization improves the male offspring rsquo;s spatial learning and memory consolidation process and motivation.