Effect of omega 3 supplementation during pregnancy and lactation on cognitive functions in rat offspring

Fatty acids play a crucial role during fetal life, a period characterized by limited time for processes such as brain development and organogenesis. The accumulation of Docosahexaenoic Acid (DHA) in the brain coincides with a growth spurt in the gray matter, particularly in the second half of pregnancy. The positive contribution of DHA to neurodevelopment in infants fed with breast milk is well-established. This study aims to investigate the impact of omega-3 supplementation initiated during preconception, the 1st, 2nd, and 3rd weeks of pregnancy, and the lactation period on cognitive functions in rat offspring. The research was conducted at Istanbul University – Cerrahpasa Experimental Medicine Research Laboratory (DETALAB) from May to September 2023. Thirty primiparous Wistar-Albino female rats (200-300 g, 8 weeks old) were used in the study. The experimental group (n:5) received 400 mg/kg/day of omega-3 supplementation during preconception, the 1st week, 2nd week, 3rd week of pregnancy, and lactation period, while the control group (n:5) did not receive any supplementation. Omega-3 intake by mothers continued until the end of the lactation period (21 days) based on their respective groups. Cognitive function testing using the Morris Water Maze Test, evaluating spatial learning and reference memory, was performed on a total of 60 offspring when they reached 45 days of age. The test consisted of a tank filled with opaque water divided into four quadrants. Circular, star-shaped, and square cues were placed in three directions on the upper wall of the pool to facilitate navigation for the rats. The goal was for the animals to find the escape platform within 60 seconds. Over four days, four trials were conducted daily, followed by a single trial (probe trial) on the fifth day. The platform's location remained constant during the trial days, but it was removed during the probe trial on the fifth day. While statistically significant differences were found in initial weights, weights before mating, pre-pregnancy weights, litter sizes, and gestation period averages among the groups (p<0.05), weight gains during pregnancy did not show a statistically significant difference between groups (p>0.05). The average time to find the platform by rat pups varied significantly across days (p=0.000), with the shortest time recorded on the 4th day. When examined by groups, average times to find the platform on the 1st and 2nd trial days were statistically significant (p<0.05), while no significant differences were observed on the 3rd and 4th days. Significant differences were found in the average times to find the platform for each trial day in sequence (p<0.05). Only the average difference between the third trials of the groups was statistically significant (p=0.049), with the preconception group finding the platform in the shortest time. In the probe trial (5th day), the percentage of time spent in the quadrant where the platform was located within 60 seconds did not show a statistically significant difference among the mean values (p>0.05). In conclusion, initiating omega-3 supplementation during the early stages of pregnancy may be more effective for both short-term and long-term memory.