Thyroxine restores hippocampal neurogenesis and synaptogenesis in a male rat model of carbimazole-induced hypothyroidism: a histological study

Abstract Background Adult-onset hypothyroidism has a deleterious effect on hippocampal cognitive and memory functions. This study was performed to evaluate the possible therapeutic of thyroxine hippocampus degeneration in an adult male rat model carbimazole-induced potentiality spontaneous recovery. Thirty-two albino rats were divided equally into four groups, as follows: I (control group), II (hypothyroidism group) received carbimazole (20 mg/kg) orally once daily for 4 weeks; III (recovery managed group II, then left untreated additional weeks assess recovery; IV (thyroxine-treated group): induced levothyroxine µg/kg/day) weeks. Rats their corresponding controls sacrificed after 8 groups IV. The levels T3, T4, TSH measured. Hematoxylin Eosin staining thyroid sections performed. Additionally, toluidine blue immunohistochemical PCNA, GFAP, synaptophysin applied sections. Both morphometric measurements statistical analysis Results Comparison thyroxine-treated with recovery revealed significant reduction level increase T3 T4 levels, well improved histological architecture both Hippocampal decrease mean area percent number PCNA-positive cells subgranular zone (SGZ); niche neural stem (NSCs) hippocampus; optical density synaptophysin. Conclusion is by can be restored replacement therapy, probably through neuronal cell preservation, synaptogenesis, stimulation neurogenesis SGZ. On other hand, from this inadequate.