BALB/C رابطه هيپوتيروييدي مادري و كاهش خارهاي دندريتي در ياخته هاي پيراميدال مغز موش

The Relation of Maternal Hypothyroidism and Dendritic Spines Reduction in Brain Pyramidal Cells of Balb/C Mice

Background: Thyroid hormones are well known to be essential for normal development of the brain in human and animals. In particular, thyroid deficiency during the prenatal periods causes significant impairments of structural development and organization of the brain. Therefore in this study, the effects of maternal hypothyroidism on morphometrical changes of synaptic sites of pyramidal cells in the mouse brain was evaluated. Materials and Methods: This study was carried out on 24 balb/c mice. The animals were divided into two experimental and control groups. The experimental group was made hypothyroid by chemical thyroidectomy with oral propylthyouracil (PTU) in drinking water, while the control group was kept intact. On the 20th postnatal day, by using histological technique preparation and histochemical staining (Golgy) method, we were able to investigate the effects of maternal thyroid hormones deficiency, on the development of pyramidal synaptogenesis in postnatal period of the mouse. Results: Our findings showed that maternal hypothyroidism during pregnancy cansed a significant decrease of the dendritic spines in the experimental group (31.08±0.45) compared with the control group (39.88±0.55), (p<0.05). In addition, an increase gap among the synaptic sites of pyramidal cells in the brain cortex among the experimental group (3.78±0.86) in contrast with the controls (2.57±1.05) were observed (p<0.005). Conclusion: The results of this study indicated that there is a key role for thyroid hormones in connection with maturation and neuronal development of brain cortex. Also hormonal reduction during pregnancy can affect the development and neuronal synaptogenesis of the next generation.