Hypothalamic Estrogen Receptor‐lmmunoreactivity in Prepubertal vs Adult Female Guinea Pigs

Olster, Deborah H.

doi:10.1111/j.1365-2826.1994.tb00627.x

Cited by 9 publications

(6 citation statements)

References 39 publications

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“…In addition to neural input, MPO is thought to be influenced directly by gonadal steroid hormones with steroid hormone-containing cells and steroid hormone receptors reported in high concentration in the nucleus of both rodents and humans (Olster, 1994;Kruijver et al, 2002Kruijver et al, , 2003. Although both MPOL and MPOM are associated with autonomic and cardiovascular regulation, the MPOL is characterized by a more direct effector pathway to the periaqueductal gray and locus coeruleus, whereas MPOM is strongly affiliated with intrahypothalamic autonomic motorelays (Simerly andSwanson, 1986, 1988;Rizvi et al, 1992;Swanson, 2000;Simerly, 2004).…”

Section: Discussionmentioning

confidence: 99%

“…The afferent input to the nucleus includes major pathways from medial amygdala and the bed nucleus of stria terminalis as well as various intrahypothalamic projections (Kita and Oomura, 1982;Shipley et al, 1996;Dong and Swanson, 2006a,b). In rodents and mammals, MPO is larger in males than in females, with sexual dimorphism apparently caused by the influence of estrogens and androgens in early development (Gorski et al, 1978;Bleier et al, 1982;Dohler, 1991;Olster, 1994).…”

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confidence: 99%

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Organization of the human medial preoptic nucleus

Koutcherov

Paxinos

Kurths

2007

J of Comparative Neurology

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The organization of the adult human medial preoptic nucleus was studied by using chemoarchitectonic markers for acetylcholinesterase, nonphosphorylated neurofilament protein (SMI-32), calbindin-D28k, neuropeptide Y (NPY), melanin-concentrating hormone (MCH), cocaine- and amphetamine-regulated transcript (CART), and 3-fucosyl-N-acetyl-lactosamine (CD15) to establish human homologs to the subnuclei making up MPO in the rat, where their connections and functional significance are better understood. The human MPO comprises three subnuclei, the medial MPO, the lateral MPO, and the dorsomedially positioned uncinate subnucleus. As in the rat, the human medial MPO is magnocellular and contains numerous NPY- and CART-immunoreactive fibers and terminals as well as calbindin-positive neurons. The human lateral MPO, like its homolog in the rat, distinctively features numerous MCH-positive fibers and terminals as well as SMI-32-immunoreactive fibers. The uncinate subnucleus is wedged between the lateral surface of the paraventricular nucleus and the medial MPO and is characterized by variable NPY- and CART-immunoreactive fibers and terminals, also seen in the rat central MPO, suggesting that the subnuclei are homologues. The intermediate nucleus was distinguished by CD15-positive neuronal staining, whereas the majority of its neurons also contained acetylcholinesterase. The human intermediate nucleus is positioned on the lateral surface of MPO and by its chemo- and cytoarchitecture constitutes a distinct nucleus of the preoptic area characterized by close structural association with the MPO complex. These findings demonstrate that the human MPO is organized similarly to the rat MPO, in chemo- and cytoarchitectonically distinct subnuclei, which implies differences in their functional specialization, as seen in the rat.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Organization of the human medial preoptic nucleus

Koutcherov

Paxinos

Kurths

2007

J of Comparative Neurology

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“…The discrepancy is most likely attributable to the more discrete analysis with in situ hybridization. Because the areas that exhibited increased mRNA expression of the ␣1 subunit after estrogen treatment coincided with the previously reported distribution of ER␣ (DonCarlos et al, 1991;Olster, 1994;Mitra et al, 2003;Merchenthaler et al, 2004;Warembourg and Leroy, 2004), we searched for EREs in the Cav3.1 ␣1 gene using Dragon Estrogen Response Element Finder (Bajic et al, 2003). We found a number of putative ERE sites in the mouse and human genome with the consensus ERE sequence being 5Ј-AT-GGCCA-TGG-TGACC-AC-3Ј.…”

Section: Distribution and Estrogen Regulation Of T-type Channel Subunitsmentioning

confidence: 99%

Estrogen Upregulates T-Type Calcium Channels in the Hypothalamus and Pituitary

Qiu¹,

Bosch²,

Jamali³

et al. 2006

J. Neurosci.

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Low voltage-activated (T-type) Ca2ϩ channels are responsible for generating low-threshold spikes (LTS) that facilitate burst firing and transmitter release in neurons. The T-type Ca 2ϩ channels contain a regulatory ␣1 subunit, and several isoforms of the ␣1 subunit (Cav3.1, 3.2, 3.3) have been cloned. The Cav 3.1 ␣1 subunit is abundantly expressed in the hypothalamus. Previously, we found that 17 ␤-estradiol (E2) increased the number of arcuate neurons expressing LTS. Therefore, we used an ovariectomized female guinea pig model to measure the distribution and regulation of Cav3.1 mRNA expression by E2. Guinea pig Cav3.1 ␣1 subunit sequences, which were cloned by PCR, were used in ribonuclease protection (RPA) and in situ hybridization assays to evaluate mRNA expression. Based on a RPA, E2 significantly increased the mRNA expression of Cav3.1 ␣1 subunit in the mediobasal hypothalamus and the pituitary. In situ hybridization analysis revealed that E2 significantly increased Cav 3.1 mRNA expression in medial preoptic nuclei, bed nuclei stria terminalis, and the arcuate nucleus. Whole-cell patch recordings in arcuate neurons revealed that E2 treatment significantly increased the peak T-type Ca 2ϩ current density by twofold without affecting the activation/inactivation characteristics and augmented the rebound excitation by threefold to fourfold. These results suggest that estrogen regulates the mRNA expression of T-type calcium channels, which leads to increased functional expression of the channel. Increased expression of T-type channels could be one mechanism by which estrogen augments burst firing and transmitter release in hypothalamic neurons.

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“…This is a fascinating finding as all previous reports in adult animals show a stimulatory effect of oestrogen on HPA activity (Yukhananov & Handa 1996, Rachman et al 1998, Viau & Meaney 2004, Lund et al 2006). Although there are data suggesting that there is little change in ER prevalence in HPA relevant areas of the CNS over puberty in the guinea pig (Olster 1994), no similar studies have been performed in the prepubertal rat.…”

Section: Discussionmentioning

confidence: 96%

“…There is a paucity of research into ER levels before, during and after puberty in female rats. Studies comparing ER immunoreactivity in various forebrain regions in prepubertal and adult female guinea pigs found no age difference in ER immunostaining in the paraventricular nucleus (PVN) or the amygdala (Olster 1994). This suggests that in rodents, these regions of the brain known to govern HPA activity in adulthood may be capable of responding to oestrogen before puberty; thus the rise in gonadal steroids over puberty may be crucial for the activation of a selection of female neuroendocrine and behavioural traits.…”

Section: Introductionmentioning

confidence: 99%

Reversal of the hypothalamo-pituitary–adrenal response to oestrogens around puberty

Evuarherhe¹,

Leggett²,

Waite³

et al. 2009

Journal of Endocrinology

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The neuroendocrine gender dimorphism that begins during perinatal development is completed during puberty. We have previously described how the perinatal gonadal steroids programme hypothalamic-pituitary-adrenal (HPA) activity in adulthood and we now assess the role of peripubertal ovarian hormones. Prepubertal females were treated subcutaneously with either cholesterol or 17b-oestradiol and their pituitary-adrenal activity was assessed 5 days later. Oestradiol suppressed the ACTH and corticosterone responses to restraint stress in the prepubertal female. Furthermore, groups of female rats were ovariectomised (OVX) either before or after puberty and adult animals were subsequently treated with subcutaneous implants containing either 17b-oestradiol or cholesterol. Corticosterone pulsatility was assessed using an automated blood sampling system to collect blood from freely moving animals at 10 min intervals over 24 h. Oestradiol administered to adults that had been OVX either pre-or postpubertally displayed a significantly higher mean corticosterone level as well as increased pulse frequency and pulse amplitude compared with cholesterol treated controls. These data demonstrate a reversal in the effect of oestrogens on HPA axis activity over the time of puberty with inhibitory effects prepubertally and stimulatory actions after puberty and imply an ovarian steroid-independent mechanism of pubertal maturation of HPA sensitivity to oestrogens.

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Hypothalamic Estrogen Receptor‐lmmunoreactivity in Prepubertal vs Adult Female Guinea Pigs

Cited by 9 publications

References 39 publications

Organization of the human medial preoptic nucleus

Organization of the human medial preoptic nucleus

Estrogen Upregulates T-Type Calcium Channels in the Hypothalamus and Pituitary

Reversal of the hypothalamo-pituitary–adrenal response to oestrogens around puberty

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