Dual Action of Electrochemical Stimulation of the Bed Nucleus of the Stria terminalis on the Release of LH

Beltramino, C.; Taleisnik, S.

doi:10.1159/000123007

Cited by 92 publications

(33 citation statements)

References 2 publications

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“…The bed nucleus of the stria terminalis (BNST) is another estradiol-sensitive GABAergic area that projects to GnRH neurons (Simerly et al, 1990;Pompolo et al, 2002;Hahn and Coen, 2006). Although electrochemical stimulation in the BNST can cause LH release (Beltramino and Taleisnik, 1980), it provides a much greater input to the medial preoptic area and AVPV in males than in females (Hutton et al, 1998); therefore, it is less likely the BNST plays a significant role in surge regulation. In embryonic nasal explant cultures, GABAergic cells provide a major synaptic input to GnRH neurons and are involved in GnRH neuron migration (Kusano et al, 1995;Bless et al, 2000); adult roles for these GABA neurons with regard to GnRH neuron regulation are unknown.…”

Section: Discussionmentioning

confidence: 99%

Estradiol Induces Diurnal Shifts in GABA Transmission to Gonadotropin-Releasing Hormone Neurons to Provide a Neural Signal for Ovulation

Christian¹,

Moenter²

2007

J. Neurosci.

121

113

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Ovulation is initiated by a surge of gonadotropin-releasing hormone (GnRH) secretion by the brain. GnRH is normally under negative feedback control by ovarian steroids. During sustained exposure to estradiol in the late follicular phase of the reproductive cycle, however, the feedback action of this steroid switches to positive, inducing the surge. Here, we used an established ovariectomized, estradiol-treated (OVXϩE) mouse model exhibiting daily surges to investigate the neurobiological mechanisms underlying this switch. Specifically, we examined changes in GABA transmission to GnRH neurons, which can be excited by GABA A receptor activation. Spontaneous GABAergic postsynaptic currents (PSCs) were recorded in GnRH neurons from OVXϩE and OVX mice in coronal and sagittal slices. There were no diurnal changes in PSC frequency in cells from OVX mice in either slice orientation. In OVXϩE cells in both orientations, PSC frequency was low during negative feedback but increased at surge onset. During the surge peak, this increase subsided in coronal slices but persisted in sagittal slices. Comparison of PSCs before and during tetrodotoxin (TTX) treatment showed TTX decreased PSC frequency in OVXϩE cells in sagittal slices, but not coronal slices. This indicates estradiol acts on multiple GABAergic afferent populations to increase transmission through both activity-dependent and -independent mechanisms. Estradiol also increased PSC amplitude during the surge. Estradiol and the diurnal cycle thus interact to induce shifts in both GABA transmission and postsynaptic response that would produce appropriate changes in GnRH neuron firing activity and hormone release.

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Section: Discussionmentioning

confidence: 99%

Estradiol Induces Diurnal Shifts in GABA Transmission to Gonadotropin-Releasing Hormone Neurons to Provide a Neural Signal for Ovulation

Christian¹,

Moenter²

2007

J. Neurosci.

121

113

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“…USA 84 (1987) Intact (5) G3 (5) V.7u. (20), and although these three regions appear to be involved in the modulation of gonadotropin release, their exact role is unclear (39,40 …”

Section: Distribution Of Cck-immunoreactive Cells In the Intactmentioning

confidence: 99%

Castration reversibly alters levels of cholecystokinin immunoreactivity within cells of three interconnected sexually dimorphic forebrain nuclei in the rat.

Simerly¹,

Swanson²

1987

Proc. Natl. Acad. Sci. U.S.A.

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Three sexually dimorphic cell groups in the forebrain of the rat-the central part of the medial preoptic nucleus, the encapsulated part of the bed nucleus of the stria terminalis, and the posterodorsal part of the medial nucleus of the amygdala-are larger in males, contain a high density of gonadal-steroid-concentrating cells, and are thought to play important roles in the control of reproductive behavior and physiology. Since each of these regions contains a large number of cholecystokinin-immunoreactive cells, we used an indirect immunohistochemical method to examine the possibility that levels of this peptide are modulated by circulating gonadal steroids in adult male rats. Rats were castrated at 60 days of age, and one group each was pretreated with colchicine and then killed 3, 7, and 14 days after gonadectomy. Castration clearly decreased CCK immunoreactivity within cells of each region, with the most dramatic effects occurring 7 and 14 days after gonadectomy, and these effects were reversed by treatment with testosterone over a 14-day period. The results suggest that CCK levels within individual cells in each of the interconnected sexually dimorphic nuclei examined here are regulated by circulating gonadal steroids and may be related to the hormonal modulation of reproductive functions thought to be mediated by these cell groups.An important role for gonadal steroid hormones in the control of reproductive behavior is well-established, although mechanisms underlying their influence on neural circuits mediating such functions remain unclear. Gonadal steroids have been shown to markedly affect biochemical indices of neurotransmitter function (see ref. 1 for review), and steroid-induced changes in the levels of putative neurotransmitters within individual neurons have been demonstrated immunohistochemically. For example, 15 weeks after gonadectomy, the density of vasopressin-immunoreactive fibers in the lateral septum is markedly reduced in the adult male rat, and vasopressin-stained cell bodies are no longer demonstrable in the bed nucleus of the stria terminalis and medial nucleus of the amygdala (2). Similarly, the density of substance Pimmunoreactive fibers decreases within 14 days after gonadectomy (3). In contrast, the distribution of serotoninimmunoreactive fibers in the medial preoptic nucleus (MPN) and the density of tyrosine hydroxylase-immunoreactive (presumably dopaminergic) cells in the anteroventral periventricular nucleus do not appear to be sensitive to the influences of circulating gonadal steroids in the adult but can be dramatically altered by manipulation of the perinatal steroid environment (4, 5).The sexual differentiation of neural structures in the mammalian brain has been documented for a number of cytological features of individual neurons, the synaptology of specific brain regions, and the volume and cytoarchitecture of several nuclei (see refs. 6 and 7 for reviews). Three such nuclei, the medial preoptic nucleus (especially its central subdivision, MPNc; ref. 8), the encaps...

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“…Additionally, LHRH immunoreactive fibers project to the interpeduncu lar nucleus and dorsal midbrain, regions which contain neurons strongly responsive to lordosis trigger stimuli, and where lesions impair lordosis in hamsters [29,30]. We can not say whether vomeronasal signals normally lead to the release of LHRH, or whether LHRH influences lordosis in dependently: however, there is evidence which implicates the accessory olfactory system in LHRH release [2][3][4]10] and in raised serum luteinising hormone, an effect that can be prevented by vomeronasal organ removal [5].…”

Section: Discussionmentioning

confidence: 99%

Removal of the Vomeronasal Organ Impairs Lordosis in Female Hamsters: Effect Is Reversed by Luteinising Hormone-Releasing Hormone

Mackay‐Sim¹,

Rose

1986

Neuroendocrinology

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In female golden hamsters, vomeronasal organ removal disrupts the elicitation of lordosis by lumbosacral tactile stimulation. A similar disruption occurs if the nasopalatine ducts are closed, without removing the vomeronasal organ. Injection of luteinising hormone-releasing hormone reverses the effect of vomeronasal organ removal. These findings suggest that chemosensory signals from the male hamster act via the accessory olfactory system, to facilitate the triggering of lordosis by somatic stimulation.

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Dual Action of Electrochemical Stimulation of the Bed Nucleus of the Stria terminalis on the Release of LH

Cited by 92 publications

References 2 publications

Estradiol Induces Diurnal Shifts in GABA Transmission to Gonadotropin-Releasing Hormone Neurons to Provide a Neural Signal for Ovulation

Estradiol Induces Diurnal Shifts in GABA Transmission to Gonadotropin-Releasing Hormone Neurons to Provide a Neural Signal for Ovulation

Castration reversibly alters levels of cholecystokinin immunoreactivity within cells of three interconnected sexually dimorphic forebrain nuclei in the rat.

Removal of the Vomeronasal Organ Impairs Lordosis in Female Hamsters: Effect Is Reversed by Luteinising Hormone-Releasing Hormone

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