Browsing by Subject "Neuroplasticity"

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    Acute and chronic estrogen supplementation decreases uterine sympathetic innervation in ovariectomized adult virgin rats
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Zoubina, E. V.; Mize, A. L.; Alper, R. H.; Smith, P. G.
    Uterine innervation undergoes substantial reorganization associated with changes in reproductive status. Nerves innervating the uterus are decreased in pregnancy and puberty, and even the normal rodent estrous cycle is characterized by fluctuations in numbers of myometrial nerve fibers. During the follicular (proestrus/estrous) phase of the estrous cycle, intact nerves are rapidly depleted and then return over the next 2-3 days in the luteal (metestrus/diestrus) phase. We hypothesize that uterine nerve depletion is initiated by increased circulating estrogen in the follicular phase . However, studies have not shown whether estrogen can reduce uterine innervation and, if so, whether the time course is compatible with the rapid changes observed in the estrous cycle. These questions were addressed in the present study. Mature ovariectomized virgin rats received 17-B-estradiol as a single injection (10 .ug/kg s.c.) or chronically from timed-release pellets (0.1 .ug/pellet for 3 weeks sustained release). Total (protein gene-product 9.S-immunoreactive) and sympathetic (dopamine B-hydroxylase-immunoreactive) uterine innervation was assessed quantitatively. Both total and sympathetic innervation was abundant in uterine longitudinal smooth muscle of ovariectomized rats. However, following acute or chronic estrogen administration, total and sympathetic fiber numbers were markedly decreased. This was not due to altered uterine size, as reductions persisted after correcting for size differences. Our results indicate that sympathetic nerves are lost from uterine smooth muscle after estradiol treatment in a manner similar to that seen in the intact animal during estrus and pregnancy. This suggests that the rise in estradiol prior to estrus is sufficient to deplete uterine sympathetic innervation.
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    The Golgi method. A historical through contemporary view
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) González Burgos, Ignacio
    Knowledge regarding the biology of the nervous system and its functions has gone through various theoretical, methodological, and interpretative stages throughout history, depending largely on technical advances that have allowed us not only to approach old questions from new perspectives but also to address new ones. One advance that constituted a watershed in the history of neuroscience was the appearance of a chrome-silver staining technique called the Golgi method that allowed the complete, three-dimensional observation of nerve cells. Discovered by Camilo Golgi and, later, modified significantly and employed by Santiago Ramón y Cajal, Golgi’s method was crucial in demonstrating the veracity of the Neuronal Theory over the earlier Reticular Theory, and in revealing numerous findings related to the human brain and those of many other animal species, which continue to be analyzed today. Despite a period of scientific recession in the first half of the 20th century, the use of the Golgi method prevailed and even expanded in the second half of that century and into the 21st, as researchers continued to use it in its original or modified form and in combination with emerging methodologies. Currently, there are no signs of any decline in its use.