The Effect of Selenium on Learning Disability Due to Maternal Hyperthyroidism During Lactation

Abstract

Purpose: Hyperthyroidism causes adverse changes in hippocampal-dependent learning/memory functions in developmental and adult periods. In the present study, the healing effect of selenium was investigated on learning disability in offspring of mothers given L-thyroxine during lactation. Materials and Methods: 12 pregnant rats were used in the study. The pregnant rats were randomly assigned into three groups (n=8/group): Male offspring of dams administered L-thyroxine (0.2 mg/kg/day) during the lactation was formed as lactational hyper-thyroidism group (LHG), male offspring of dams administered selenium between 39-60 days after induced lactational hyperthyroid-ism was formed as lactational hyperthyroidism+selenium group (LH+SeG), male offspring of dams administered SF during the lacta-tion period was formed the control group (KG). Spatial learning/memory functions were measured with the Morris water maze (n=16/group). All measurements were made when offspring rats were 60-66 days. Results: Post-hoc test with one-way ANOVA revealed that LHG rats were found on the platform by traveling longer distances and swimming longer than the control group (p0.005). There was also not any significant difference between the groups in terms of the time spent in the target quadrant in the probe trial. Conclusion: The study findings show that high thyroid hormone levels in mother rats during lactation have long-term negative effects on hippocampal-dependent learning function in offspring rats, and selenium has a healing effect on these disorders.

Keywords

• lactational hyperthyroidism
• selenium
• learning and memory
• morris water maze