title: Hippocampal serotonin-2A receptor-immunoreactive neurons density increases after testosterone therapy in the gonadectomized male mice.
abstract: The change of steroid levels may also exert different modulatory effects on the number and class of serotonin receptors present in the plasma membrane. The effects of chronic treatment of testosterone for anxiety were examined and expression of 5-HT2Aserotonergic receptor, neuron, astrocyte, and dark neuron density in the hippocampus of gonadectomized male mice was determined. Thirty-six adult male NMRI mice were randomly divided into six groups: intact-no testosterone treatment (No T), gonadectomy (GDX)-No T, GDX-Vehicle, GDX-6.25 mg/kg testosterone (T), GDX-12.5 mg/kg T, and GDX-25 mg/kg T. Anxiety-related behavior was evaluated using elevated plus maze apparatus. The animals were anesthetized after 48 hours after behavioral testing, and decapitated and micron slices were prepared for immunohistochemical as well as histopathological assessment. Subcutaneous injection of testosterone (25 mg/kg) may induce anxiogenic-like behavior in male mice. In addition, immunohistochemical data reveal reduced expression of 5-HT2Aserotonergic receptor after gonadectomy in all areas of the hippocampus. However, treatment with testosterone could increase the mean number of dark neurons as well as immunoreactive neurons in CA1 and CA3 area, dose dependently. The density of 5-HT2Areceptor-immunoreactive neurons may play a crucial role in the induction of anxiety like behavior. As reduction in such receptor expression have shown to significantly enhance anxiety behaviors. However, replacement of testosterone dose dependently enhances the number of 5-HT2Areceptor-immunoreactive neurons and interestingly also reduced anxiety like behaviors.
authors.affiliation: Neuroscience Research Center, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Emsehgol
authors.initials: E
authors.lastname: Nikmahzar
authors.affiliation: Department of Anatomy, Neuroscience Research Center, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Jahanshahi
authors.affiliation: Shefa Neuroscience Research Center, Tehran, Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Ghaemi
authors.affiliation: Department of Anatomy, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Gholam Reza
authors.initials: GR
authors.lastname: Naseri
authors.affiliation: Department of Anatomy, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Moharreri
authors.affiliation: Shefa Neuroscience Research Center, Tehran, Iran.
authors.forename: Ahmad Ali
authors.initials: AA
authors.lastname: Lotfinia
keywords: 5-HT2A serotonergic receptor; Anxiety; Gonadectomy; Hippocampus; Testosterone