Indian Journal of Veterinary Pathology

The experiment was conducted to evaluate neurobehavioural alterations, histopathology and electron microscopic changes in brain of hypothyroidism induced rats. 21 days old weaned female Sprague drawly rats (96) were divided into 8 groups with 12 No. in each group. They were treated as Group 1: Euthyroid, Group 2: Hypothyroidism induced with methimazole @ 0.02%, Group 3: Hypothyroid + LT4, Group 4:Withania somnifera root extract control, Group 5: Hypothyroid + Withania somnifera root extract, Group 6: Shilajit control, Group 7: Hypothyroid + Shilajit and Group 8: Hypothyroid + Withania somnifera root extract + Shilajit, both @ 100 mg/Kg b. wt. At the end of 3 months, 6 rats from each group were sacrificed and brains were collected for histopathology and electron microscopic studies. The remaining rats were mated with euthyroid adult males and all the 48 pregnant rats were administered with treatments as above till the 17^th day of gestation. The F₁ generation pups were reared till 21 days to study neurobehavioral parameters and were sacrificed to collect brain and thyroid for histopathology and electron microscopy studies. Histopathology and TEM sections of group II brains, in parent stock and F₁ generation revealed neuronal swelling, reduced nissil substance, satellitosis, neuronophagia and apoptosis. TEM revealed swollen nucleus, condensed mitochondria, loss of cristae and matrix, irregular discontinuous endoplasmic reticulum and loss of nuclear membrane. The present study showed neurological alterations in hypothyroidism model and usage of herbal drugs have beneficiary role in alleviating the effects of hypothyroidism.