Effects of maternal hypothroidism during preganacy on anxiety-like behaviors in adulthood rats: Impact of moderate treadmill exercise

Previous study indicated that the lack of thyroid hormones during brain development can be associated with structural and biochemical changes in the brain that can cause psychological disorders. Physical exercise affects brain neurochemistry and may be amilorate behavioral deficit in hypothyroidism. The aim of this study was to determine the impact of moderate forced exercise on the effects of maternal hypothyroidism on anxiety-like behaviors in adulthood rats.
For the induction of hypothyroidism , 6-propyl-2-thiourycil (PTU) was added to the drinking water (50 and 200 mg/L) of mothers, from the 6th prenatal day to the 21th postnatal day. Maternal hypothyroid adult offspring were exercised on treadmill with moderat intensity for 2 weeks. For measuring the anxiety, animal were tested in an elevated plus maze (EPM) and light and dark box (L/D).
Induction of hypothyroidism during the rat fetal and early postnatal period increased anxiety-like behavior in both EPM and L/D box tasks. Treadmill exercise with moderate intensity, during the postnatal period did not affect the levels of anxiety significantly. Also forced exercise alone increased anxiety behavior significantly.
These findings indicated that maternal hypothyroidism increase anxiety-like behaviors and treadmill exercise with moderate intensity did not amilroate this behavior. Moreover, physical activity in moderate intensity had anxiogenic effects.