The Role of the Medial and Central Amygdala in Stress-Induced Suppression of Pulsatile LH Secretion in Female Rats

Lin, Yuanshao; Li, Xiaofeng; Lupi, Micol; Kinsey‐Jones, James S.; Shao, Baiqi; Lightman, Stafford L.; O’Byrne, Kevin

doi:10.1210/en.2010-1003

Cited by 56 publications

(58 citation statements)

References 70 publications

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“…To allow the anchorage of a metal spring to protect exteriorized chronically implanted intravenous catheters, the animals were fitted with a tether screw on the skull. The rats were fitted with indwelling cardiac catheter via the left jugular vein, as described previously (Lin et al 2011). The catheter was exteriorized at the back of the head and secured to a cranial attachment; the rats were fitted with a 30 cm-long metal spring tether (Instec Laboratories Inc., Boulder, CO, USA).…”

Section: Head Screws and Intravenous Cannulationmentioning

confidence: 99%

Maternal high-fat diet influences stroke outcome in adult rat offspring

Lin

Shao

Zhou

et al. 2015

Journal of Molecular Endocrinology

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Diet-induced epigenetic modifications in early life could contribute to later health problem. However, it remains to be established whether high-fat diet (HFD) consumption during pregnancy and the suckling period could predispose the offspring to stroke. The present study investigated the influence of maternal HFD on stroke outcome in adult offspring. Female Sprague-Dawley rats were fed a normal diet (5.3% fat) or a HFD (25.7% fat), just before pregnancy until the end of lactation. Male offspring were fed with the control diet or the HFD after weaning, to form four groups (control offspring fed with the control diet (C/C) or the HFD (C/HFD) and offspring of fat-fed dams fed with the control diet (HFD/C) or the HFD (HFD/HFD)). The offspring received middle cerebral artery occlusion on day 120 followed by behavioral tests (neurological deficit score, staircase-reaching test and beam-traversing test), and infarct volumes were also calculated. We found that the HFD/C rats displayed larger infarct volume and aggravated functional deficits (all P!0.05), compared with the C/C rats, indicating that maternal fat-rich diet renders the brain more susceptible to the consequences of ischemic injury. Moreover, maternal HFD offspring displayed elevated glucocorticoid concentrations following stroke, and increased glucocorticoid receptor expression. In addition, adrenalectomy reversed the effects of maternal HFD on stroke outcome when corticosterone was replaced at baseline, but not ischemic, concentrations. Furthermore, expression of brain-derived neurotrophic factor (BDNF) in the ipsilateral hippocampus was decreased in the HFD/C offspring (P!0.05), compared with the C/C offspring. Taken together, maternal diet can substantially influence adult cerebrovascular health, through the programming of central BDNF expression and the hypothalamic-pituitary-adrenal axis.

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Section: Head Screws and Intravenous Cannulationmentioning

confidence: 99%

Maternal high-fat diet influences stroke outcome in adult rat offspring

Lin

Shao

Zhou

et al. 2015

Journal of Molecular Endocrinology

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“…This rim was formerly called the ventromedial "molecular" layer [20]. Among other functions, the MeA subnuclei are important for the interpretation of the social relevance of both olfactory and vomeronasal stimuli [21][22][23][24][25]; the response to genitosensorial stimulation, modulation of sexual behavior in males and females, and sexual satiety [9,[26][27][28][29][30][31]; maternal behavior or avoidance of the offspring [32,33]; anxiety and conditioned or innate fear [34,35]; and, emotional processing or neuroendocrine responses to stressful stimuli [36][37][38][39]. The finding that various social behaviors can be modulated by the same MeA subnuclei suggests that local cells integrate different demands from specific pathways.…”

Section: Morphological Features Of the Medial Amygdalamentioning

confidence: 99%

Morphological and Functional Features of the Sex Steroid-Responsive Posterodorsal Medial Amygdala of Adult Rats

Rasia‐Filho

Haas²,

Oliveira³

et al. 2012

MRMC

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The rat posterodorsal medial amygdala (MePD) expresses receptors for gonadal hormones and integrates sex steroid-sensitive subcortical networks. Male-female differences are found in the morphology, connectivity, and local neuropil structure of MePD. For example, dendritic spine density is sexually-dimorphic and changes with the estrous cycle and following gonadal hormones manipulations. Due to its connectivity, the MePD may affect emotionally-loaded social behaviors, according to a former Newman's seminal proposition. Unilateral fiber-sparing ibotenic acid damage of the MePD does not impair male sexual behavior. However, microinjecting glutamate and histamine into the right MePD facilitates ejaculation. Further, MePD-lesioned rats are not different from normal rats in anxiety-like behavior as evaluated by the elevated plus maze test or innate fear test induced by a live cat. In another study, an adapted model for inducing aggressive behavior in rats by a brief period of restraint prior to the resident-intruder paradigm was used to study Fos-immunoreactivity in the MePD. Following stressful stimulation (restraint) or the restraint and fight condition, but not after aggression alone, Fos-immunoreactivity was detected in the MePD. Microinjecting the inhibitory neuropeptide somatostatin into the right MePD notably reduces fighting behavior without affecting locomotion. Overall, these data indicate that sex steroids and local neurochemical stimulatory/inhibitory transmitters modulate the MePD and reinforce the idea that this area is a node for modulating social behavior neural networks.

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“…The mechanism by which the suppressive effects of stress are relayed to the GnRH pulse generator are currently unknown, although previous studies have strongly implicated the involvement of the CRH signaling system (9): the activation of either of the 2 subtypes of CRH receptor, CRHR1 and CRHR2, by their endogenous ligands, CRH and the related urocortin neuropeptides (Ucn, UcnII, and UcnIII) (10). Major populations of CRH neurons are found within the parvocellular portion of the paraventricular nucleus of the hypothalamus (PVN), central and medial nuclei of the amygdala, and the bed nucleus of the stria terminalis (BNST) (11,12), all of which play a key role in the regulation of the hypothalamo-pituitary adrenal (HPA) axis during stress and have been implicated in the stress-induced suppression of the GnRH pulse generator (13)(14)(15).…”

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confidence: 99%

“…Several lines of evidence substantiate this hypothesis: 1) intra-ARC injections of senktide suppressed LH pulses in the OVX ϩ E 2 rat (33) in a dose-dependent manner; 2) an increase in c-Fos expression has been detected in the ARC of follicular phase ewes subjected to LPS challenge and coincided with augmented CRHR2 immunoreactivity in these regions (73); and 3) the ARC receives direct input from the CRH-rich BNST (74 -77) that appears to induce activation of GABA-ergic neurons in response to CRH stimulation (15). The BNST is, in turn, innervated by glutamatergic CRH neurons of the central nuclei of the amygdala (78), the neurotoxic lesioning of which abolishes the LPS-induced suppression of the LH pulse in OVX ϩ E 2 rats (14). Based on this evidence we propose that limbic activation of ARC NKB neurons underlies the immunologic stress response, and that ARC NKB/NK3R signaling is responsible for adrenocorticotropic stimulation and suppression of the hypothalamicpituitary-gonadal axis following acute stress exposure.…”

mentioning

confidence: 99%

Neurokinin B Signaling in the Female Rat: a Novel Link Between Stress and Reproduction

Grachev

Li²,

Hu³

et al. 2014

Endocrinology

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Acute systemic stress disrupts reproductive function by inhibiting pulsatile gonadotropin secretion. The underlying mechanism involves stress-induced suppression of the GnRH pulse generator, the functional unit of which is considered to be the hypothalamic arcuate nucleus kisspeptin/neurokinin B/dynorphin A neurons. Agonists of the neurokinin B (NKB) receptor (NK3R) have been shown to suppress the GnRH pulse generator, in a dynorphin A (Dyn)-dependent fashion, under hypoestrogenic conditions, and Dyn has been well documented to mediate several stress-related central regulatory functions. We hypothesized that the NKB/Dyn signaling cascade is required for stress-induced suppression of the GnRH pulse generator. To investigate this ovariectomized rats, iv administered with Escherichia coli lipopolysaccharide (LPS) following intracerebroventricular pretreatment with NK3R or κ-opioid receptor (Dyn receptor) antagonists, were subjected to frequent blood sampling for hormone analysis. Antagonism of NK3R, but not κ-opioid receptor, blocked the suppressive effect of LPS challenge on LH pulse frequency. Neither antagonist affected LPS-induced corticosterone secretion. Hypothalamic arcuate nucleus NKB neurons project to the paraventricular nucleus, the major hypothalamic source of the stress-related neuropeptides CRH and arginine vasopressin (AVP), which have been implicated in the stress-induced suppression of the hypothalamic-pituitary-gonadal axis. A separate group of ovariectomized rats was, therefore, used to address the potential involvement of central CRH and/or AVP signaling in the suppression of LH pulsatility induced by intracerebroventricular administration of a selective NK3R agonist, senktide. Neither AVP nor CRH receptor antagonists affected the senktide-induced suppression of the LH pulse; however, antagonism of type 2 CRH receptors attenuated the accompanying elevation of corticosterone levels. These data indicate that the suppression of the GnRH pulse generator by acute systemic stress requires hypothalamic NKB/NK3R signaling and that any involvement of CRH therewith is functionally upstream of NKB.

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The Role of the Medial and Central Amygdala in Stress-Induced Suppression of Pulsatile LH Secretion in Female Rats

Abstract: Medial and central nuclei of the amygdala play a key role in psychogenic and immunological stress-induced suppression of the GnRH pulse generator, respectively.

Cited by 56 publications

References 70 publications

Maternal high-fat diet influences stroke outcome in adult rat offspring

Maternal high-fat diet influences stroke outcome in adult rat offspring

Morphological and Functional Features of the Sex Steroid-Responsive Posterodorsal Medial Amygdala of Adult Rats

Neurokinin B Signaling in the Female Rat: a Novel Link Between Stress and Reproduction

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