Modulation of NR1 subunit of N-methyl-D-aspartate receptor by ovariectomy and passive avoidance learning

Learning and memory are the most intensively studied subjects in neuroscience. Various approaches have been used to understand the underlying cellular and molecular mechanisms. Numerous studies have shown that different sites of brain are involved in learning and memory mechanisms. Two sites of mammalian brain that show high density of these receptors are CA1 region of hippocampus and Purkinje cell layer of cerebellum. Twenty four Sprague-Dawley rats were used in 4 groups: Control-1 (intact without learning); control-2 (intact with learning); ovariectomy (OVX) without learning and OVX with learning. A shuttle box apparatus used for passive avoidance learning procedure. Immunohistochemical procedure was used for determination of NR1 subunit of N-methyl-D-aspartate (NMDA) receptor. Photoshop software was used for determination of color intensity. Immunohistological finding of this experiment indicated that OVX has a negative effect on density of NR1 subunit of NMDA receptors in two brain regions. Other finding of this study showed that passive avoidance learning significantly increased density of NR1 subunit of NMDA receptors in two brain regions. These results indicated that the sex hormone can modulate function and expression of the NR1 subunit of NMDA receptor in CA1 region of hippocampus and Purkinje cell layer of cerebellum.