Examinando por Autor "Garcia Segura, Luis"

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    Estrogen receptor beta and G protein-coupled estrogen receptor 1 are involved in the acute estrogenic regulation of arginine-vasopressin immunoreactive levels in the supraoptic and paraventricular hypothalamic nuclei of female rats
    (Elsevier, 2019-06-01) Lagunas, Natalia; Marraudino, Marilena; Amorim, Miguel de; Pinos Sánchez, María Elena; Collado Guirao, Paloma; Panzica, GianCarlo; Garcia Segura, Luis ; Grassi, Daniela
    The ovarian hormone 17β-estradiol is known to regulate the release, expression and immunoreactivity of arginine-vasopressin (AVP) in the supraoptic and paraventricular hypothalamic nuclei of rodents. Previous studies have shown that estrogen receptor α is involved in the effects of chronic estradiol administration on arginine-vasopressin immunoreactivity in the female rat hypothalamus. In this study we have examined the effect of an acute administration of estradiol or specific agonists for estrogen receptors α, β and G protein-coupled estrogen receptor 1 on the immunoreactivity of arginine-vasopressin in the hypothalamus of adult ovariectomized female rats. Acute estradiol administration resulted in a significant decrease in the number of arginine-vasopressin immunoreactive neurons in the supraoptic and paraventricular nuclei after 24 h. The effects of the specific estrogen receptors agonists suggest that the action of estradiol on arginine-vasopressin immunoreactivity is mediated in the supraoptic nucleus by G protein-coupled estrogen receptor 1 and in the paraventricular nucleus by both estrogen receptor β and G protein-coupled estrogen receptor 1. Thus, in contrast to previous studies on the effect of chronic estrogenic treatments, the present findings suggest that estrogen receptor β and G protein-coupled estrogen receptor 1 mediate the acute effects of estradiol on arginine-vasopressin immunoreactivity in the hypothalamus of ovariectomized rats.
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    G Protein-Coupled Estrogen Receptor Immunoreactivity Fluctuates During the Estrous Cycle and Show Sex Differences in the Amygdala and Dorsal Hippocampus
    (Frontiers Media, 2020) Llorente, Ricardo; Marraudino, Marilena; Bonaldo, Brigitta; Simon Areces, Julia; Abellanas Pérez, Pedro; Rivero Aguilar, Marina; Fernández García, José Manuel; Pino Osuna, María José; Garcia Segura, Luis ; Grassi, Daniela; Carrillo Urbano, Beatriz; Collado Guirao, Paloma
    G protein-coupled estrogen receptor (GPER) in the amygdala and the dorsal hippocampus mediates actions of estradiol on anxiety, social recognition and spatial memory. In addition, GPER participates in the estrogenic regulation of synaptic function in the amygdala and in the process of adult neurogenesis in the dentate gyrus. While the distribution of the canonical estrogen receptors α and β in the amygdala and dorsal hippocampus are well characterized, little is known about the regional distribution of GPER in these brain regions and whether this distribution is affected by sex or the stages of the estrous cycle. In this study we performed a morphometric analysis of GPER immunoreactivity in the posterodorsal medial, anteroventral medial, basolateral, basomedial and central subdivisions of the amygdala and in all the histological layers of CA1 and the dentate gyrus of the dorsal hippocampal formation. The number of GPER immunoreactive cells was estimated in these different structures. GPER immunoreactivity was detected in all the assessed subdivisions of the amygdaloid nucleus and dorsal hippocampal formation. The number of GPER immunoreactive cells was higher in males than in estrus females in the central (P = 0.001) and the posterodorsal medial amygdala (P < 0.05); higher in males than in diestrus females in the strata orients (P < 0.01) and radiatum-lacunosum-moleculare (P < 0.05) of CA1-CA3 and in the molecular layer of the dentate gyrus (P < 0.01); higher in diestrus females than in males in the basolateral amygdala (P < 0.05); higher in diestrus females than in estrus females in the central (P < 0.01), posterodorsal medial (P < 0.01) and basolateral amygdala (P < 0.01) and higher in estrus females than in diestrus females in the strata oriens (P < 0.05) and radiatum-lacunosum-moleculare (P < 0.05) of CA1-CA3 and in the molecular layer (P < 0.05) and the hilus of the dentate gyrus (P < 0.05). The findings suggest that estrogenic regulation of the amygdala and hippocampus through GPER may be different in males and in females and may fluctuate during the estrous cycle.
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    G protein-coupled estrogen receptor immunoreactivity in the rat hypothalamus is widely distributed in neurons, astrocytes and oligodendrocytes, fluctuates during the estrous cycle and is sexually dimorphic
    (Karger International, 2021-06-29) Marraudino, Marilena; Carrillo Urbano, Beatriz; Bonaldo, Brigitta; Llorente, Ricardo; Campioli, Elia; Garate, Iciar; Pinos Sánchez, María Elena; Garcia Segura, Luis; Collado Guirao, Paloma; Grassi, Daniela
    Introduction: The membrane-associated G protein-coupled estrogen receptor 1 (GPER) mediates the regulation by estradiol of arginine-vasopressin immunoreactivity in the supraoptic and paraventricular hypothalamic nuclei of female rats and is involved in the estrogenic control of hypothalamic regulated functions, such as food intake, sexual receptivity, and lordosis behavior. Objective: To assess GPER distribution in the rat hypothalamus. Methods: GPER immunoreactivity was assessed in different anatomical subdivisions of five selected hypothalamic regions of young adult male and cycling female rats: the arcuate nucleus, the lateral hypothalamus, the paraventricular nucleus, the supraoptic nucleus, and the ventromedial hypothalamic nucleus. GPER immunoreactivity was colocalized with NeuN as a marker of mature neurons, GFAP as a marker of astrocytes, and CC1 as a marker of mature oligodendrocytes. Results: GPER immunoreactivity was detected in hypothalamic neurons, astrocytes, and oligodendrocytes. Sex and regional differences and changes during the estrous cycle were detected in the total number of GPER-immunoreactive cells and in the proportion of neurons, astrocytes, and oligodendrocytes that were GPER-immunoreactive. Conclusions: These findings suggest that estrogenic regulation of hypothalamic function through GPER may be different in males and females and may fluctuate during the estrous cycle in females.