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Increased cortical plasticity in the elderly: changes in the somatosensory cortex after paired associative stimulation. Neuroscience 2009; 163:266-76. [PMID: 19524024 DOI: 10.1016/j.neuroscience.2009.06.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 05/20/2009] [Accepted: 06/06/2009] [Indexed: 02/08/2023]
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Inghilleri M, Conte A, Currà A, Frasca V, Lorenzano C, Berardelli A. Ovarian hormones and cortical excitability. An rTMS study in humans. Clin Neurophysiol 2004; 115:1063-8. [PMID: 15066531 DOI: 10.1016/j.clinph.2003.12.003] [Citation(s) in RCA: 172] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2003] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Ovarian steroids influence neural excitability. Using repetitive transcranial magnetic stimulation (rTMS) we investigated changes in cortical excitability during the menstrual cycle. METHODS Eight women underwent rTMS on Days 1 and 14 of the menstrual cycle. As a control group, 8 age-matched men were also tested twice, with a 14-day interval between the two experimental sessions. Repetitive magnetic pulses were delivered in trains of 10 stimuli (5 Hz frequency and 120% of the motor threshold calculated at rest) to the left motor area of the first dorsal interosseous muscle. RESULTS In women, the motor evoked potential (MEP) size did not increase on Day 1, but it increased progressively during the train on Day 14. The duration of the silent period progressively lengthened during the train on both days. In men the MEP increased in size, and the silent period lengthened to a similar extent on both days. CONCLUSIONS In women, hormone changes related to the menstrual cycle alter cortical excitability. SIGNIFICANCE Low estrogen levels probably reduce cortical excitability because their diminished action on sodium channels reduces recruitment of excitatory interneurons during rTMS thus abolishing the MEP facilitation.
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Affiliation(s)
- M Inghilleri
- Department of Neurological Sciences, University of Rome La Sapienza, Viale dell'Università 30, 00185 Rome, Italy.
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3
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Persad V, Ting Wong CG, Cortez MA, Wang YT, Snead OC. Hormonal regulation of atypical absence seizures. Ann Neurol 2004; 55:353-61. [PMID: 14991813 DOI: 10.1002/ana.10831] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A time course study that examined the effects of the female estrous cycle on the chronic slow spike-and-wave discharges (SSWDs), gamma-aminobutyric B receptor (GABA(B)R) binding, and GABA(B)R protein expression was conducted in Long Evans hooded rats treated during development with a cholesterol synthesis inhibitor AY9944 (AY). In addition, a pharmacological study using the hormones progesterone, 17 beta-estradiol, mifepristone (intracellular progesterone receptor antagonist), tamoxifen (intracellular estrogen receptor antagonist), and allopregnanolone (progesterone metabolite) was performed to determine their effects on AY-induced seizures. The data indicate that there is a significant increase in both the duration of SSWD and GABA(B)R binding in the AY model, during the proestrus stage of the estrous cycle, the stage during which the levels of progesterone are at their highest. No changes in GABA(B)R1a or R2 protein levels were observed. In addition, the administration of both progesterone and allopregnanolone exacerbated seizures in the AY model, whereas 17 beta-estradiol attenuated the SSWD duration. Neither mifepristone nor tamoxifen blocked the effects of progesterone and 17 beta-estradiol, respectively, on SSWD duration in the AY model, suggesting that these two sex hormones are working in a manner independent of their intracellular receptors. These data suggest an important role for steroid hormones in the regulation and maintenance of AY-induced atypical absence seizures.
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MESH Headings
- Analysis of Variance
- Animals
- Animals, Newborn
- Anticholesteremic Agents/toxicity
- Blotting, Western/methods
- Cell Line
- Disease Models, Animal
- Electroencephalography/drug effects
- Embryo, Mammalian
- Epilepsy, Absence/chemically induced
- Epilepsy, Absence/drug therapy
- Epilepsy, Absence/metabolism
- Estrous Cycle/metabolism
- Female
- Functional Laterality
- Hormones/metabolism
- Hormones/therapeutic use
- Humans
- Kidney
- Male
- Organophosphorus Compounds/pharmacokinetics
- Pregnancy
- Protein Binding
- Rats
- Rats, Long-Evans
- Receptors, GABA-B/genetics
- Receptors, GABA-B/metabolism
- Sex Characteristics
- Time Factors
- Transfection
- Tritium/pharmacokinetics
- trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride/toxicity
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Affiliation(s)
- Vasan Persad
- Institute of Medical Science, Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
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4
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van Luijtelaar G, Budziszewska B, Tetich M, Lasoń W. Finasteride inhibits the progesterone-induced spike-wave discharges in a genetic model of absence epilepsy. Pharmacol Biochem Behav 2003; 75:889-94. [PMID: 12957232 DOI: 10.1016/s0091-3057(03)00162-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Previously, it was found that progesterone aggravates spike-wave discharges (SWD) in WAG/Rij rats in a nongenomic way. In order to elucidate whether the regulatory effect of progesterone depends on its conversion to allopregnanolone, the effect of finasteride, a 5alpha-reductase inhibitor, on progesterone-induced increase in SWD was studied in the same model for absence epilepsy. Progesterone (10 and 20 mg/kg ip) dose-dependently increased the number of SWD (by 54% and 97%, respectively) during the first hour postinjection. Pretreatment of rats with finasteride (50 mg/kg sc) blocked the progesterone-induced enhancement of SWD. Finasteride alone had no effect on the number of SWD, up to 24 h following its administration. It is concluded that finasteride blocked the progesterone-induced increase in SWD, which indicates that this action of progesterone is mediated by its neuroactive metabolite allopregnanolone.
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Aloisi AM, Della Seta D, Rendo C, Ceccarelli I, Scaramuzzino A, Farabollini F. Exposure to the estrogenic pollutant bisphenol A affects pain behavior induced by subcutaneous formalin injection in male and female rats. Brain Res 2002; 937:1-7. [PMID: 12020856 DOI: 10.1016/s0006-8993(02)02446-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We investigated the effects of perinatally administered bisphenol A (BPA), an environmental contaminant with estrogenic activity, on formalin-induced nociceptive responses. Male and female offspring of mother rats treated with BPA or oil were cross-fostered after birth to obtain three homogeneous groups: BPA-prenatal, receiving BPA via the placenta; BPA-postnatal, receiving BPA through suckling; OIL, control, from mothers receiving only peanut oil (vehicle). All groups underwent a pain test with s.c. formalin injection (50 microl, 10%) or were sham injected (pricking with a syringe needle) in the dorsal hind paw. They were immediately placed in an open field apparatus where pain responses (licking, flexing and paw-jerk) were recorded for 60 min. Corticosterone, testosterone and estradiol serum levels were determined in blood obtained at the end of the experiment. BPA-prenatal treatment induced an increase in licking duration in females and in flexing duration in both sexes in the first half of the test (0-30 min after formalin injection). BPA-postnatal treatment induced a decrease in paw-jerk frequency in males and females during the second part of the test (30-60 min after formalin injection). Plasma concentrations of corticosterone, estradiol and testosterone did not differ significantly between groups. These results indicate that exposure to BPA modified the activity of neural pathways and/or centers involved in nociception and pain in a sex-related and exposure-related manner.
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Affiliation(s)
- Anna Maria Aloisi
- Institute of Human Physiology, University of Siena, Via Aldo Moro, 53100 Siena, Italy.
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6
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van Luijtelaar G, Budziszewska B, Jaworska-Feil L, Ellis J, Coenen A, Lasoń W. The ovarian hormones and absence epilepsy: a long-term EEG study and pharmacological effects in a genetic absence epilepsy model. Epilepsy Res 2001; 46:225-39. [PMID: 11518624 DOI: 10.1016/s0920-1211(01)00277-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In the first experiment, the relationship between the phase of the estrous cycle and the number of spontaneously occurring spike-wave discharges was investigated in WAG/Rij rats, a model for generalized absence epilepsy. The electroencephalogram (EEG) was continuously recorded for 96 h in eight rats chronically equipped with cortical EEG electrodes. A circadian pattern emerged for the number of spike-wave discharges: a nadir during the first hours of the light period, and an acrophase during the first hours of the dark period. This daily maximum was increased at proestrus day compared with the other days of the cycle, when the plasma level of progesterone is enhanced specifically at these hours of this day. This suggests that progesterone enhances spike-wave discharges. There was no difference in the first few hours of the light period in the number of spike-wave discharges between proestrus and the three other days, suggesting that estradiol has no effect on spike-wave discharges. In the second study, the effects of the systemic administration of progesterone and 17 beta-estradiol on spike-wave discharges and spontaneous behavior were investigated. It was shown that progesterone (20 and 30 mg/kg) but not estradiol (0.17-1.5 mg/kg) increased the number and total duration of spike-wave discharges. On the other hand, injection of RU 38486 (10 and 30 mg/kg), an antagonist of intracellular progesterone receptors, had no effect on spike-wave discharges and did not block the stimulatory effect of progesterone. The antagonist of 17 beta-estradiol tamoxifen (1 and 3 mg/kg) did not evoke alterations in the number or duration of spike-wave discharges. Our results indicate that progesterone aggravates spike-wave discharges, but is not mediated through intracellular receptors. Since progesterone is rapidly metabolized in the brain to the positive modulator of GABA(A) receptor allopregnanolone, which increases spike-wave discharges in WAG/Rij rats, it is possible that the epileptiformic effects of progesterone are mediated through this metabolite.
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Affiliation(s)
- G van Luijtelaar
- Department of Physiological Psychology, NICI, University of Nijmegen, PO Box 9104, 6500 HE Nijmegen, The Netherlands.
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Prevot V, Bouret S, Croix D, Takumi T, Jennes L, Mitchell V, Beauvillain JC. Evidence that members of the TGFbeta superfamily play a role in regulation of the GnRH neuroendocrine axis: expression of a type I serine-threonine kinase receptor for TGRbeta and activin in GnRH neurones and hypothalamic areas of the female rat. J Neuroendocrinol 2000; 12:665-70. [PMID: 10849211 DOI: 10.1046/j.1365-2826.2000.00508.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The present study was designed to determine whether transforming growth factor (TGF)beta and/or activin participate in the regulation of the gonadotropin releasing hormone (GnRH) neuroendocrine axis in vivo. Single-label in situ hybridization histochemistry was used to determine the anatomical distribution of a TGFbeta and activin type I receptor (B1) mRNA, in the adult female rat hypothalamic areas that are known to be important sites for the regulation of reproduction. Dual-label in situ hybridization histochemistry was performed to determine whether B1 mRNA was expressed in GnRH neurones. The results of these studies revealed an extensive distribution of B1 mRNA in the hypothalamic regions, including diagonal bands of Broca, preoptic area, arcuate nucleus and median eminence. In the median eminence, B1 mRNA was detected in tanycytes and in the endothelial cells of the pituitary portal blood capillaries. Dual-label in situ hybridization histochemistry showed that 31+/-5% of GnRH neurones expressed B1 mRNA, thus providing evidence that TGFbeta and/or activin can act directly on GnRH neurones to modulate their activity. Taken together, these data provide morphological arguments in favour of a participation of TGFbeta and/or activin in the regulation of reproduction at the hypothalamic level.
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Affiliation(s)
- V Prevot
- INSERM U422, Lille Cedex, France.
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Prevot V, Croix D, Bouret S, Dutoit S, Tramu G, Stefano GB, Beauvillain JC. Definitive evidence for the existence of morphological plasticity in the external zone of the median eminence during the rat estrous cycle: implication of neuro-glio-endothelial interactions in gonadotropin-releasing hormone release. Neuroscience 1999; 94:809-19. [PMID: 10579572 DOI: 10.1016/s0306-4522(99)00383-8] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Despite intense investigation, the demonstration of morphological plasticity in the external zone of the median eminence concerning the gonadotropin-releasing hormone system has never been reported. In this study, we investigate whether dynamic transformations of the gonadotropin-releasing hormone nerve terminals and/or tanycytes in the external zone of the median eminence of the hypothalamus occurred during the rat estrous cycle, by following individual gonadotropin-releasing hormone-immunoreactive nerve terminals on serial ultrathin sections observed by electron microscopy. Female rats were killed at 16.00 diestrus II (n = 3), i.e. when estrogen levels are basal and gonadotropin-releasing hormone release is low, and at 16.00 proestrus (n = 4), i.e. when estrogen levels peak and the preovulatory gonadotropin-releasing hormone surge occurs. Our results show that, in the median eminence obtained from proestrus rats, 12+/-2% of the gonadotropin-releasing hormone nerve terminals were observed to make physical contact with the parenchymatous basal lamina, i.e. the pericapillary space. In the median eminence obtained from diestrus II rats, no contacts were observed. On proestrus, numerous physical contacts between gonadotropin-releasing hormone nerve terminals and the basal lamina occurred by evagination of the basal lamina and/or by emerging processes from gonadotropin-releasing hormone nerve terminals. The quantification of the evagination of the basal lamina revealed that the basal lamina was at least twofold more tortuous in appearance during proestrus. These results demonstrate for the first time the existence of dynamic plastic changes in the external zone of the median eminence, allowing gonadotropin-releasing hormone nerve terminals to contact the pericapillary space on the day of proestrus, thus facilitating the release of the neurohormone into the pituitary portal blood.
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Affiliation(s)
- V Prevot
- INSERM U 422, IFR 22, Neuroendocrinologie et physiopathologie neuronale, place de Verdun, Lille, France.
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9
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Fink G, Sumner BE, McQueen JK, Wilson H, Rosie R. Sex steroid control of mood, mental state and memory. Clin Exp Pharmacol Physiol 1998; 25:764-75. [PMID: 9784914 DOI: 10.1111/j.1440-1681.1998.tb02151.x] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
1. Sex steroid hormones exert profound effects on mood and mental state. Thus, in women, oestrogen is thought to protect against depression and delay the onset of schizophrenia and Alzheimer's disease. 2. Our studies in the female rat show that oestradiol, in its positive feedback mode for gonadotrophin release, increases the expression of genes for the 5-hydroxytryptamine 5-HT2A receptor and the serotonin transporter (SERT) in the dorsal raphe nucleus and the density of 5-HT2A receptor and SERT sites in regions of the forebrain that, in the human, are concerned with cognition, mental state, emotion and memory. 3. In the male rat, castration decreases while oestrogen and testosterone, but not 5 alpha-dihydrotestosterone (5 alpha-DHT), increase the density of 5-HT2A receptors in forebrain. The fact that 5 alpha-DHT has no effect suggests that the action of testosterone depends on its conversion to oestradiol by aromatase. 4. In intact rats, the density of 5-HT2A receptors in cerebral cortex is significantly higher in pro-oestrous female than in male and dioestrous female rats, showing that the spontaneous, preovulatory surge of oestradiol that reaches a peak at 12.00 h of pro-oestrus also increases the density of 5-HT2A receptors in cortex. 5. Oestrogen and testosterone (by way of its conversion to oestrogen) also stimulate the expression of the arginine vasopressin gene in the bed nucleus of the stria terminalis of the rodent, a mechanism that plays a key role in olfactory memory. 6. These actions of sex steroid hormones are discussed in the context of genomic versus non-genomic mechanisms, the recent discovery that there are two oestradiol receptors with different distributions in brain, the significance of our findings for our understanding of the control of mood, mental state and memory and the mechanism by which oestrogen stimulation of the 5-HT2A receptor could delay the onset of Alzheimer's disease.
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Affiliation(s)
- G Fink
- MRC Brain Metabolism Unit, University Department of Pharmacology, Edinburgh, United Kingdom.
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10
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Prevot V, Dutoit S, Croix D, Tramu G, Beauvillain JC. Semi-quantitative ultrastructural analysis of the localization and neuropeptide content of gonadotropin releasing hormone nerve terminals in the median eminence throughout the estrous cycle of the rat. Neuroscience 1998; 84:177-91. [PMID: 9522372 DOI: 10.1016/s0306-4522(97)00537-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The ultrastructural appearance of gonadotropin releasing hormone-immunoreactive elements was studied in the external zone of the median eminence of adult female Wistar rats. On the one hand, the purpose of the study was to determine the distribution of gonadotropin releasing hormone terminals towards the parenchymatous basal lamina at the level of hypothalamo-hypophyseal portal vessels, throughout the estrous cycle. On the other hand, we have semi-quantified the gonadotropin releasing hormone content in nerve terminals or preterminals during this physiological condition. A morphometric study was coupled to a colloidal 15 mn gold postembedding immunocytochemistry procedure. Animals were killed at 09.00 on diestrus II, 0.900, 10.00, 13.00, 17.00 and 18.00 on proestrus and 09.00 on estrus (n = 4-8 rats/group). A preliminary light microscopic study was carried out to identify an antero-posterior part of median eminence strongly immunostained by anti-gonadotropin releasing hormone antibodies but which was, in addition, easily spotted. This last condition was necessary to make a good comparison between each animal. Contacts between gonadotropin releasing hormone nerve terminals and the basal lamina were observed only the day of proestrus. Such contacts, however, were rare and in the great majority of cases, gonadotropin releasing hormone terminals are separated from basal lamina by tanycytic end feet. The morphometric analysis showed no significant variation in average distance between gonadotropin releasing hormone terminals and capillaries throughout the estrous cycle. Consequently, it did not appear that a large neuroglial plasticity exists during the estrous cycle. However, the observation of contacts only on proestrus together with some ultrastructural images evoke the possibility of a slight plasticity. The semi-quantitative results show that the content of gonadotropin releasing hormone in the nerve endings presented two peaks on proestrus: one at 09.00 (23 +/- 5 particles/micrograms2, P < 0.03) before the onset of luteinizing hormone surge, and the second at 18.00 (16 +/- 2 particles/micrograms2, P < 0.01) concomitantly with the luteinizing hormone surge, when compared to baseline values on proestrus 10.00 (8 +/- particles/micrograms2).
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Affiliation(s)
- V Prevot
- U 422 Institut National de la Santé et de La Recherche Médicale, Lille, France
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Abstract
Gonadal steroid hormones may affect, simultaneously, a wide variety of neuronal targets, influencing the way the brain reacts to many external and internal stimuli. Some of the effects of these hormones are permanent, whereas others are short lasting and transitory. The ways gonadal steroids affect brain function are very versatile and encompass intracellular, as well as, membrane receptors. In some cases, these compounds can interact with several neurotransmitter systems and/or transcription factors modulating gene expression. Knowledge about the mechanisms implicated in steroid hormone action will facilitate the understanding of brain sexual dimorphism and how we react to the environment, to drugs, and to certain disease states.
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Affiliation(s)
- R Alonso
- Department of Physiology, Canarian University Hospital, University of La Laguna School of Medicine, Santa Cruz de Tenerife, Spain.
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McQueen JK, Wilson H, Fink G. Estradiol-17 beta increases serotonin transporter (SERT) mRNA levels and the density of SERT-binding sites in female rat brain. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1997; 45:13-23. [PMID: 9105666 DOI: 10.1016/s0169-328x(96)00233-1] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The aim of the present study was to determine the effect of estradiol-17 beta (E2), in its positive feedback mode for gonadotropin release, on the serotonin transporter (SERT) in female rat brain. Levels of SERT mRNA were determined by in situ hybridization and SERT-binding sites were measured by quantitative [3H]paroxetine receptor autoradiography. The injection of estradiol benzoate (EB) in acutely ovariectomized rats increased significantly (approximately 50%) the numbers of cells that expressed SERT mRNA in the dorsal raphe nucleus and the density of SERT-binding sites in lateral septum (90%), basolateral amygdala (20%), ventral nucleus of thalamus (250%) and ventromedial hypothalamic nucleus (250%). SERT-binding sites in EB-treated rats were significantly lower in periaqueductal central grey (15%). These findings indicate that effects on SERT gene expression may be involved in the E2-induction of the gonadotropin surge. Together with our previous findings, they also suggest that the sex differences in depression and the apparent psychotropic effect of E2 may be due to the action of E2 on the serotonin transporter as well as 5-HT2A receptors.
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Affiliation(s)
- J K McQueen
- MRC Brain Metabolism Unit, University Department of Pharmacology, Edinburgh, Scotland, UK
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Alonso-Solís R, Abreu P, López-Coviella I, Hernández G, Fajardo N, Hernández-Díaz F, Díaz-Cruz A, Hernández A. Gonadal steroid modulation of neuroendocrine transduction: a transynaptic view. Cell Mol Neurobiol 1996; 16:357-82. [PMID: 8818402 DOI: 10.1007/bf02088101] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
1. Steroid hormones act on neuronal communication through different mechanisms, ranging from transynaptic modulation of neurotransmitter synthesis and release to development and remodeling of synaptic circuitry. Due the wide distribution of putative brain targets for steroid hormones, acute or sustained elevations of their circulating levels may affect, simultaneously, a variety of neuronal elements. In an elementary mode of interaction, steroids are able to modulate both the synthesis and release of a neurotransmitter at a particular synapse, and the response of its target postsynaptic cells. Using two neuroendocrine transducing systems-the rat pineal gland and the GT1-7 cell line-we have examined these interactions and the following findings are discussed in this article. 2. In the rat, pineal melatonin production is partially controlled by gonadal hormones. In females, melatonin synthesis and secretion is reduced during the night of proestrus, apparently as a consequence of elevated estradiol and progesterone levels. In males, circulating testosterone seems to be necessary to maintain the amplitude of the nocturnal melatonin peak. 3. Some gonadal effects on pineal activity are exerted on its noradrenergic input, since changes in circulating steroid hormone levels are able to induce acute modifications of tyrosine hydroxylase activity in pineal sympathetic nerve terminals. 4. Gonadal steroids are also able to regulate the response of pineal cells to adrenergic stimulation, since in vivo treatment of both male and female rats with steroid hormone blockers induces profound modifications in adrenergically-induced accumulation of cyclic AMP (cAMP) in dispersed pinealocytes. 5. Direct exposure of pineal cells from gonadectomized female and male rats to estradiol (E2) or testosterone (T), respectively, potentiates pinealocyte response to adrenergic activation. In addition, short-term (15 min) exposure to either progesterone (Pg) or progesterone coupled to bovine serum albumin (P-3-BSA) suppresses the E2-dependent potentiation of adrenergic response in female rat pinealocytes. 6. Exposure of GT1-7 cells to E2 completely blocked the norepinephrine (NE)-induced elevation of cAMP content. In E2-treated GT1-7 cells, additional exposure (15 min) to either Pg or P-3-BSA abolished E2-dependent inhibition of NE responsiveness. In addition, P-3-BSA alone increased basal cAMP levels in GT1-7 cells, regardless previous exposure to E2. 7. In conclusion, there are evidences, both from the current literature and from the present results, supporting the view that in some neuroendocrine systems gonadal hormones modulate neurotransmission by acting, simultaneously, at pre- and postsynaptic sites. The models presented here constitute appropriate examples of this transynaptic mode of steroid and, therefore, may offer a useful approach to investigate steroid hormone actions on the brain.
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Affiliation(s)
- R Alonso-Solís
- Department of Physiology, University of La Laguna School of Medicine, Tenerife, Spain
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14
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Fink G, Sumner BE, Rosie R, Grace O, Quinn JP. Estrogen control of central neurotransmission: effect on mood, mental state, and memory. Cell Mol Neurobiol 1996; 16:325-44. [PMID: 8818400 DOI: 10.1007/bf02088099] [Citation(s) in RCA: 275] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
1. Estrogen exerts profound effects on mood, mental state and memory by acting on both "classical" monoamine and neuropeptide transmitter mechanisms in brain. Here we review an example of each type of action. 2. With respect to the effect of estrogen on central monoamine neurotransmission, low levels of estrogen in women are associated with the premenstrual syndrome, postnatal depression and post-menopausal depression. Sex differences in schizophrenia have also been attributed to estrogen. Previous studies have shown that estrogen stimulates a significant increase in dopamine2 (D2) receptors in the striatum. Here we show for the first time that estrogen also stimulates a significant increase in the density of 5-hydroxytryptamine2A (5-HT2A) binding sites in anterior frontal, cingulate and primary olfactory cortex and in the nucleus accumbens, areas of the brain concerned with the control of mood, mental state, cognition, emotion and behavior. These findings explain, for example, the efficacy of estrogen therapy or 5-HT uptake blockers such as fluoxetine in treating the depressive symptoms of the premenstrual syndrome. and suggest that the sex differences in schizophrenia may also be due to an action of estrogen mediated by way of 5-HT2A receptors. 3. With respect to the effect of estrogen on central neuropeptide transmission, estrogen stimulates the expression of the arginine vasopressin (AVP) gene in the bed nucleus of the stria terminalis (BNST) in rodents. This results in a 100-fold increase in AVP mRNA in the BNST and a massive increase in AVP peptide in the BNST and its projections to the lateral septum and lateral habenula. The BNST-AVP system enhances and/or maintains "social" or "olfactory" memory, and thus provides a powerful model for correlating transcriptional control of neuropeptide gene expression with behavior. Whether similar mechanisms operate in the human remain to be determined. 4. These two examples of the action of estrogen on central neurotransmission are discussed in terms of their immediate clinical importance for the treatment of depressive symptoms, their use as powerful models for investigations on the steroid control of central neurotransmitter mechanisms, and the role of estrogen as "Nature's" psychoprotectant.
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MESH Headings
- Affect/drug effects
- Affect/physiology
- Animals
- Arginine Vasopressin/biosynthesis
- Arginine Vasopressin/genetics
- Arginine Vasopressin/physiology
- Aromatase/metabolism
- Base Sequence
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Brain Chemistry/drug effects
- Cerebral Cortex/drug effects
- Cerebral Cortex/metabolism
- Depression, Postpartum/physiopathology
- Depression, Postpartum/psychology
- Dopamine/physiology
- Estradiol/pharmacology
- Estrogens/physiology
- Female
- Gene Expression Regulation/drug effects
- Humans
- Hypothalamo-Hypophyseal System/drug effects
- Hypothalamo-Hypophyseal System/metabolism
- Male
- Memory/drug effects
- Memory/physiology
- Mental Disorders/physiopathology
- Mice
- Mice, Mutant Strains
- Molecular Sequence Data
- Mood Disorders/physiopathology
- Nucleus Accumbens/drug effects
- Nucleus Accumbens/metabolism
- Premenstrual Syndrome/physiopathology
- Premenstrual Syndrome/psychology
- Rats
- Rats, Wistar
- Receptor, Serotonin, 5-HT2A
- Receptors, Dopamine D2/biosynthesis
- Receptors, Dopamine D2/genetics
- Receptors, Serotonin/biosynthesis
- Receptors, Serotonin/genetics
- Schizophrenia/physiopathology
- Serotonin/physiology
- Selective Serotonin Reuptake Inhibitors/pharmacology
- Sex Characteristics
- Synaptic Transmission/drug effects
- Synaptic Transmission/physiology
- Testosterone/metabolism
- Up-Regulation/drug effects
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Affiliation(s)
- G Fink
- MRC Brain Metabolism Unit, University Department of Pharmacology, Edinburgh, UK
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