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Taubøll E, Isojärvi JIT, Herzog AG. The interactions between reproductive hormones and epilepsy. HANDBOOK OF CLINICAL NEUROLOGY 2021; 182:155-174. [PMID: 34266590 DOI: 10.1016/b978-0-12-819973-2.00011-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
There are complex interactions between hormones, epilepsy, and antiepileptic drugs (AEDs). While there is ample evidence that hormones influence epilepsy, it is also apparent that epileptic activity influences hormones in both women and men. In addition, AEDs may disturb endocrine function. The clinical importance of these interactions is primarily related to the effects on reproductive hormones, which is the focus of this article. Reproductive endocrine dysfunction is common among women and men with epilepsy. Menstrual disorders, polycystic ovaries, and infertility have been described among women with epilepsy, while reduced potency and sperm abnormalities have been found in men. Sexual problems and endocrine changes have been frequently described in both sexes. Epilepsy and AEDs can target a number of substrates to impact hormone levels. These include the limbic system, hypothalamus, pituitary, peripheral endocrine glands, liver, and adipose tissue. AEDs may also alter the synthesis of steroids and binding proteins, as well as hormone metabolism, and produce direct gonadal effects.
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Affiliation(s)
- Erik Taubøll
- Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway.
| | | | - Andrew G Herzog
- Harvard Neuroendocrine Unit, Beth Israel Deaconess Medical Center, Boston, MA, United States; Faculty of Medicine, Harvard Medical School, Boston, MA, United States
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Antipsychotic effects of sex hormones and atypical hemispheric asymmetries. Cortex 2020; 127:313-332. [DOI: 10.1016/j.cortex.2020.02.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 02/27/2020] [Accepted: 02/29/2020] [Indexed: 12/16/2022]
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Lengel D, Huh JW, Barson JR, Raghupathi R. Progesterone treatment following traumatic brain injury in the 11-day-old rat attenuates cognitive deficits and neuronal hyperexcitability in adolescence. Exp Neurol 2020; 330:113329. [PMID: 32335121 DOI: 10.1016/j.expneurol.2020.113329] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/13/2020] [Accepted: 04/22/2020] [Indexed: 12/18/2022]
Abstract
Traumatic brain injury (TBI) in children younger than 4 years old results in cognitive and psychosocial deficits in adolescence and adulthood. At 4 weeks following closed head injury on postnatal day 11, male and female rats exhibited impairment in novel object recognition memory (NOR) along with an increase in open arm time in the elevated plus maze (EPM), suggestive of risk-taking behaviors. This was accompanied by an increase in intrinsic excitability and frequency of spontaneous excitatory post-synaptic currents (EPSCs), and a decrease in the frequency of spontaneous inhibitory post-synaptic currents in layer 2/3 neurons within the medial prefrontal cortex (PFC), a region that is implicated in both object recognition and risk-taking behaviors. Treatment with progesterone for the first week after brain injury improved NOR memory at the 4-week time point in both sham and brain-injured rats and additionally attenuated the injury-induced increase in the excitability of neurons and the frequency of spontaneous EPSCs. The effect of progesterone on cellular excitability changes after injury may be related to its ability to decrease the mRNA expression of the β3 subunit of the voltage-gated sodium channel and increase the expression of the neuronal excitatory amino acid transporter 3 in the medial PFC in sham- and brain-injured animals and also increase glutamic acid decarboxylase mRNA expression in sham- but not brain-injured animals. Progesterone treatment did not affect injury-induced changes in the EPM test. These results demonstrate that administration of progesterone immediately after TBI in 11-day-old rats reduces cognitive deficits in adolescence, which may be mediated by progesterone-mediated regulation of excitatory signaling mechanisms within the medial PFC.
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Affiliation(s)
- Dana Lengel
- Program in Neuroscience, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, PA United States of America
| | - Jimmy W Huh
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States of America
| | - Jessica R Barson
- Program in Neuroscience, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, PA United States of America; Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Ramesh Raghupathi
- Program in Neuroscience, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, PA United States of America; Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States of America.
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Olsen RW. GABA A receptor: Positive and negative allosteric modulators. Neuropharmacology 2018; 136:10-22. [PMID: 29407219 PMCID: PMC6027637 DOI: 10.1016/j.neuropharm.2018.01.036] [Citation(s) in RCA: 185] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 01/23/2018] [Accepted: 01/25/2018] [Indexed: 12/11/2022]
Abstract
gamma-Aminobutyric acid (GABA)-mediated inhibitory neurotransmission and the gene products involved were discovered during the mid-twentieth century. Historically, myriad existing nervous system drugs act as positive and negative allosteric modulators of these proteins, making GABA a major component of modern neuropharmacology, and suggesting that many potential drugs will be found that share these targets. Although some of these drugs act on proteins involved in synthesis, degradation, and membrane transport of GABA, the GABA receptors Type A (GABAAR) and Type B (GABABR) are the targets of the great majority of GABAergic drugs. This discovery is due in no small part to Professor Norman Bowery. Whereas the topic of GABABR is appropriately emphasized in this special issue, Norman Bowery also made many insights into GABAAR pharmacology, the topic of this article. GABAAR are members of the ligand-gated ion channel receptor superfamily, a chloride channel family of a dozen or more heteropentameric subtypes containing 19 possible different subunits. These subtypes show different brain regional and subcellular localization, age-dependent expression, and potential for plastic changes with experience including drug exposure. Not only are GABAAR the targets of agonist depressants and antagonist convulsants, but most GABAAR drugs act at other (allosteric) binding sites on the GABAAR proteins. Some anxiolytic and sedative drugs, like benzodiazepine and related drugs, act on GABAAR subtype-dependent extracellular domain sites. General anesthetics including alcohols and neurosteroids act at GABAAR subunit-interface trans-membrane sites. Ethanol at high anesthetic doses acts on GABAAR subtype-dependent trans-membrane domain sites. Ethanol at low intoxicating doses acts at GABAAR subtype-dependent extracellular domain sites. Thus GABAAR subtypes possess pharmacologically specific receptor binding sites for a large group of different chemical classes of clinically important neuropharmacological agents. This article is part of the "Special Issue Dedicated to Norman G. Bowery".
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Affiliation(s)
- Richard W Olsen
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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Hausmann M. Why sex hormones matter for neuroscience: A very short review on sex, sex hormones, and functional brain asymmetries. J Neurosci Res 2016; 95:40-49. [DOI: 10.1002/jnr.23857] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 07/01/2016] [Accepted: 07/11/2016] [Indexed: 01/17/2023]
Affiliation(s)
- Markus Hausmann
- Department of Psychology; Durham University; Durham United Kingdom
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Allitt BJ, Johnstone VPA, Richards K, Yan EB, Rajan R. Progesterone Exacerbates Short-Term Effects of Traumatic Brain Injury on Supragranular Responses in Sensory Cortex and Over-Excites Infragranular Responses in the Long Term. J Neurotrauma 2015; 33:375-89. [PMID: 26258958 DOI: 10.1089/neu.2015.3946] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Progesterone (P4) has been suggested as a neuroprotective agent for traumatic brain injury (TBI) because it ameliorates many post-TBI sequelae. We examined the effects of P4 treatment on the short-term (4 days post-TBI) and long-term (8 weeks post-TBI) aftermath on neuronal processing in the rodent sensory cortex of impact acceleration-induced diffuse TBI. We have previously reported that in sensory cortex, diffuse TBI induces a short-term hypoexcitation that is greatest in the supragranular layers and decreases with depth, but a long-term hyperexcitation that is exclusive to the supragranular layers. Now, adult male TBI-treated rats administered P4 showed, in the short term, even greater suppression in neural responses in supragranular layers but a reversal of the TBI-induced suppression in granular and infragranular layers. In long-term TBI there were only inconsistent effects of P4 on the TBI-induced hyperexcitation in supragranular responses but infragranular responses, which were not affected by TBI alone, were elevated by P4 treatment. Intriguingly, the effects in the injured brain were almost identical to P4 effects in the normal brain, as seen in sham control animals treated with P4: in the short term, P4 effects in the normal brain were identical to those exercised in the injured brain and in the long term, P4 effects in the normal brain were rather similar to what was seen in the TBI brain. Overall, these results provide no support for any protective effects of P4 treatment on neuronal encoding in diffuse TBI, and this was reflected in sensorimotor and other behavior tasks also tested here. Additionally, the effects suggest that mechanisms used for P4 effects in the normal brain are also intact in the injured brain.
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Affiliation(s)
- Benjamin J Allitt
- 1 Department of Physiology, Monash University , Clayton VIC, Australia
| | - Victoria P A Johnstone
- 1 Department of Physiology, Monash University , Clayton VIC, Australia .,2 Current address: School of Anatomy, Physiology & Human Biology, The University of Western Australia , Crawley WA, Australia
| | - Katrina Richards
- 1 Department of Physiology, Monash University , Clayton VIC, Australia
| | - Edwin B Yan
- 1 Department of Physiology, Monash University , Clayton VIC, Australia
| | - Ramesh Rajan
- 1 Department of Physiology, Monash University , Clayton VIC, Australia
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Taubøll E, Heuser K, Sveberg L, Svalheim S. Experimental models for the study of hormonal changes in epilepsy. ZEITSCHRIFT FUR EPILEPTOLOGIE 2015. [DOI: 10.1007/s10309-015-0001-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Taubøll E, Sveberg L, Svalheim S. Interactions between hormones and epilepsy. Seizure 2015; 28:3-11. [PMID: 25765693 DOI: 10.1016/j.seizure.2015.02.012] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 02/08/2015] [Accepted: 02/12/2015] [Indexed: 11/18/2022] Open
Abstract
There is a complex, bidirectional interdependence between sex steroid hormones and epilepsy; hormones affect seizures, while seizures affect hormones thereby disturbing reproductive endocrine function. Both female and male sex steroid hormones influence brain excitability. For the female sex steroid hormones, progesterone and its metabolites are anticonvulsant, while estrogens are mainly proconvulsant. The monthly fluctuations in hormone levels of estrogen and progesterone are the basis for catamenial epilepsy described elsewhere in this issue. Androgens are mainly anticonvulsant, but the effects are more varied, probably because of its metabolism to, among others, estradiol. The mechanisms for the effects of sex steroid hormones on brain excitability are related to both classical, intracellularly mediated effects, and non-classical membrane effects due to binding to membrane receptors. The latter are considered the most important in relation to epilepsy. The different sex steroids can also be further metabolized within the brain to different neurosteroids, which are even more potent with regard to their effect on excitability. Estrogens potentiate glutamate responses, primarily by potentiating NMDA receptor activity, but also by affecting GABA-ergic mechanisms and altering brain morphology by increasing dendritic spine density. Progesterone and its main metabolite 5α-pregnan-3α-ol-20-one (3α-5α-THP) act mainly to enhance postsynaptic GABA-ergic activity, while androgens enhance GABA-activated currents. Seizures and epileptic discharges also affect sex steroid hormones. There are close anatomical connections between the temporolimbic system and the hypothalamus controlling the endocrine system. Several studies have shown that epileptic activity, especially mediated through the amygdala, alters reproductive function, including reduced ovarian cyclicity in females and altered sex steroid hormone levels in both genders. Furthermore, there is an asymmetric activation of the hypothalamus with unilateral amygdala seizures. This may, again, be the basis for the occurrence of different reproductive endocrine disorders described for patients with left-sided or right-sided temporal lobe epilepsy.
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Affiliation(s)
- Erik Taubøll
- Department of Neurology, Oslo University Hospital - Rikshospitalet, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Line Sveberg
- Department of Neurology, Oslo University Hospital - Rikshospitalet, Oslo, Norway
| | - Sigrid Svalheim
- Department of Neurology, Oslo University Hospital - Rikshospitalet, Oslo, Norway
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Barth C, Villringer A, Sacher J. Sex hormones affect neurotransmitters and shape the adult female brain during hormonal transition periods. Front Neurosci 2015; 9:37. [PMID: 25750611 PMCID: PMC4335177 DOI: 10.3389/fnins.2015.00037] [Citation(s) in RCA: 364] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 01/26/2015] [Indexed: 12/21/2022] Open
Abstract
Sex hormones have been implicated in neurite outgrowth, synaptogenesis, dendritic branching, myelination and other important mechanisms of neural plasticity. Here we review the evidence from animal experiments and human studies reporting interactions between sex hormones and the dominant neurotransmitters, such as serotonin, dopamine, GABA and glutamate. We provide an overview of accumulating data during physiological and pathological conditions and discuss currently conceptualized theories on how sex hormones potentially trigger neuroplasticity changes through these four neurochemical systems. Many brain regions have been demonstrated to express high densities for estrogen- and progesterone receptors, such as the amygdala, the hypothalamus, and the hippocampus. As the hippocampus is of particular relevance in the context of mediating structural plasticity in the adult brain, we put particular emphasis on what evidence could be gathered thus far that links differences in behavior, neurochemical patterns and hippocampal structure to a changing hormonal environment. Finally, we discuss how physiologically occurring hormonal transition periods in humans can be used to model how changes in sex hormones influence functional connectivity, neurotransmission and brain structure in vivo.
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Affiliation(s)
- Claudia Barth
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany ; Clinic of Cognitive Neurology, University of Leipzig Leipzig, Germany ; Leipzig Research Center for Civilization Diseases, University of Leipzig Leipzig, Germany ; Integrated Research and Treatment Center Adiposity Diseases, University of Leipzig Leipzig, Germany ; Berlin School of Mind and Brain, Mind and Brain Institute Berlin, Germany
| | - Julia Sacher
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany ; Clinic of Cognitive Neurology, University of Leipzig Leipzig, Germany
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Olsen RW. Allosteric ligands and their binding sites define γ-aminobutyric acid (GABA) type A receptor subtypes. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2015; 73:167-202. [PMID: 25637441 DOI: 10.1016/bs.apha.2014.11.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
GABAA receptors (GABA(A)Rs) mediate rapid inhibitory transmission in the brain. GABA(A)Rs are ligand-gated chloride ion channel proteins and exist in about a dozen or more heteropentameric subtypes exhibiting variable age and brain regional localization and thus participation in differing brain functions and diseases. GABA(A)Rs are also subject to modulation by several chemotypes of allosteric ligands that help define structure and function, including subtype definition. The channel blocker picrotoxin identified a noncompetitive channel blocker site in GABA(A)Rs. This ligand site is located in the transmembrane channel pore, whereas the GABA agonist site is in the extracellular domain at subunit interfaces, a site useful for low energy coupled conformational changes of the functional channel domain. Two classes of pharmacologically important allosteric modulatory ligand binding sites reside in the extracellular domain at modified agonist sites at other subunit interfaces: the benzodiazepine site and the high-affinity, relevant to intoxication, ethanol site. The benzodiazepine site is specific for certain GABA(A)R subtypes, mainly synaptic, while the ethanol site is found at a modified benzodiazepine site on different, extrasynaptic, subtypes. In the transmembrane domain are allosteric modulatory ligand sites for diverse chemotypes of general anesthetics: the volatile and intravenous agents, barbiturates, etomidate, propofol, long-chain alcohols, and neurosteroids. The last are endogenous positive allosteric modulators. X-ray crystal structures of prokaryotic and invertebrate pentameric ligand-gated ion channels, and the mammalian GABA(A)R protein, allow homology modeling of GABA(A)R subtypes with the various ligand sites located to suggest the structure and function of these proteins and their pharmacological modulation.
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Affiliation(s)
- Richard W Olsen
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
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Olsen RW. Analysis of γ-aminobutyric acid (GABA) type A receptor subtypes using isosteric and allosteric ligands. Neurochem Res 2014; 39:1924-41. [PMID: 25015397 DOI: 10.1007/s11064-014-1382-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/30/2014] [Accepted: 07/02/2014] [Indexed: 11/30/2022]
Abstract
The GABAA receptors (GABAARs) play an important role in inhibitory transmission in the brain. The GABAARs could be identified using a medicinal chemistry approach to characterize with a series of chemical structural analogues, some identified in nature, some synthesized, to control the structural conformational rigidity/flexibility so as to define the 'receptor-specific' GABA agonist ligand structure. In addition to the isosteric site ligands, these ligand-gated chloride ion channel proteins exhibited modulation by several chemotypes of allosteric ligands, that help define structure and function. The channel blocker picrotoxin identified a noncompetitive channel blocker site in GABAARs. This ligand site is located in the transmembrane channel pore, whereas the GABA agonist site is in the extracellular domain at subunit interfaces, a site useful for low energy coupled conformational changes of the functional channel domain. Also in the trans-membrane domain are allosteric modulatory ligand sites, mostly positive, for diverse chemotypes with general anesthetic efficacy, namely, the volatile and intravenous agents: barbiturates, etomidate, propofol, long-chain alcohols, and neurosteroids. The last are apparent endogenous positive allosteric modulators of GABAARs. These binding sites depend on the GABAAR heteropentameric subunit composition, i.e., subtypes. Two classes of pharmacologically very important allosteric modulatory ligand binding site reside in the extracellular domain at modified agonist sites at other subunit interfaces: the benzodiazepine site, and the low-dose ethanol site. The benzodiazepine site is specific for certain subunit combination subtypes, mainly synaptically localized. In contrast, the low-dose (high affinity) ethanol site(s) is found at a modified benzodiazepine site on different, extrasynaptic, subtypes.
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Affiliation(s)
- Richard W Olsen
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Room CHS 23-120, 650 Young Drive South, Los Angeles, CA, 90095-1735, USA,
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Ocklenburg S, Wolf CC, Heed T, Ball A, Cramer H, Röder B, Güntürkün O. Multisensory integration across the menstrual cycle. Front Psychol 2013; 4:666. [PMID: 24069015 PMCID: PMC3781309 DOI: 10.3389/fpsyg.2013.00666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 09/05/2013] [Indexed: 01/15/2023] Open
Abstract
Evidence suggests that spatial processing changes across time in naturally cycling women, which is likely due to neuromodulatory effects of steroid hormones. Yet, it is unknown whether crossmodal spatial processes depend on steroid hormones as well. In the present experiment, the crossmodal congruency task was used to assess visuo-tactile interactions in naturally cycling women, women using hormonal contraceptives and men. Participants adopted either a crossed or uncrossed hands posture. It was tested whether a postural effect of hand crossing on multisensory interactions in the crossmodal congruency task is modulated by women's cycle phase. We found that visuotactile interactions changed according to cycle phase. Naturally cycling women showed a significant difference between the menstrual and the luteal phase for crossed, but not for uncrossed hands postures. The two control groups showed no test sessions effects. Regression analysis revealed a positive relation between estradiol levels and the size of crossmodal congruency effects (CCE), indicating that estradiol seems to have a neuromodulatory effect on posture processing.
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Affiliation(s)
- Sebastian Ocklenburg
- Department of Biopsychology, Institute of Cognitive Neuroscience, Ruhr-University Bochum Bochum, Germany
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Smith SS. The influence of stress at puberty on mood and learning: role of the α4βδ GABAA receptor. Neuroscience 2013; 249:192-213. [PMID: 23079628 PMCID: PMC3586385 DOI: 10.1016/j.neuroscience.2012.09.065] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/21/2012] [Accepted: 09/25/2012] [Indexed: 11/22/2022]
Abstract
It is well-known that the onset of puberty is associated with changes in mood as well as cognition. Stress can have an impact on these outcomes, which in many cases, can be more influential in females, suggesting that gender differences exist. The adolescent period is a vulnerable time for the onset of certain psychopathologies, including anxiety disorders, depression and eating disorders, which are also more prevalent in females. One factor which may contribute to stress-triggered anxiety at puberty is the GABAA receptor (GABAR), which is known to play a pivotal role in anxiety. Expression of α4βδ GABARs increases on the dendrites of CA1 pyramidal cells at the onset of puberty in the hippocampus, part of the limbic circuitry which governs emotion. This receptor is a sensitive target for the stress steroid 3α-OH-5[α]β-pregnan-20-one or [allo]pregnanolone, which paradoxically reduces inhibition and increases anxiety during the pubertal period (post-natal day ∼35-44) of female mice in contrast to its usual effect to enhance inhibition and reduce anxiety. Spatial learning and synaptic plasticity are also adversely impacted at puberty, likely a result of increased expression of α4βδ GABARs on the dendritic spines of CA1 hippocampal pyramidal cells, which are essential for consolidation of memory. This review will focus on the role of these receptors in mediating behavioral changes at puberty. Stress-mediated changes in mood and cognition in early adolescence may have relevance for the expression of psychopathologies in adulthood.
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Affiliation(s)
- S S Smith
- Department of Physiology and Pharmacology, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
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Zuloaga DG, Yahn SL, Pang Y, Quihuis AM, Oyola MG, Reyna A, Thomas P, Handa RJ, Mani SK. Distribution and estrogen regulation of membrane progesterone receptor-β in the female rat brain. Endocrinology 2012; 153:4432-43. [PMID: 22778216 PMCID: PMC3423618 DOI: 10.1210/en.2012-1469] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although several studies have reported the localization of membrane progesterone (P(4)) receptors (mPR) in various tissues, few have attempted to describe the distribution and regulation of these receptors in the brain. In the present study, we investigated expression of two mPR subtypes, mPRα and mPRβ, within regions of the brain, known to express estradiol (E(2))-dependent [preoptic area (POA) and hypothalamus] and independent (cortex) classical progestin receptors. Saturation binding and Scatchard analyses on plasma membranes prepared from rat cortex, hypothalamus, and POA demonstrated high-affinity, specific P(4)-binding sites characteristic of mPR. Using quantitative RT-PCR, we found that mPRβ mRNA was expressed at higher levels than mPRα, indicating that mPRβ may be the primary mPR subtype in the rat brain. We also mapped the distribution of mPRβ protein using immunohistochemistry. The mPRβ-immunoreactive neurons were highly expressed in select nuclei of the hypothalamus (paraventricular nucleus, ventromedial hypothalamus, and arcuate nucleus), forebrain (medial septum and horizontal diagonal band), and midbrain (oculomotor and red nuclei) and throughout many areas of the cortex and thalamus. Treatment of ovariectomized female rats with E(2) benzoate increased mPRβ immunoreactivity within the medial septum but not the medial POA, horizontal diagonal band, or oculomotor nucleus. Together, these findings demonstrate a wide distribution of mPRβ in the rodent brain that may contribute to functions affecting behavioral, endocrine, motor, and sensory systems. Furthermore, E(2) regulation of mPRβ indicates a mechanism through which estrogens can regulate P(4) function within discrete brain regions to potentially impact behavior.
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Affiliation(s)
- Damian G Zuloaga
- Department of Basic Medical Sciences, University of Arizona College of Medicine, 425 North 5th Street, Phoenix, Arizona 85004, USA.
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Beck KD, Wasserman MC, Furst SJ, Pang KC, Servatius RJ. Differential effects of progesterone and medroxyprogesterone on delay eyeblink conditioning in ovariectomized rats. Neurobiol Learn Mem 2012; 97:148-55. [DOI: 10.1016/j.nlm.2011.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 10/17/2011] [Accepted: 11/07/2011] [Indexed: 10/15/2022]
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Pinto-Almazán R, Calzada-Mendoza CC, Campos-Lara MG, Guerra-Araiza C. Effect of chronic administration of estradiol, progesterone, and tibolone on the expression and phosphorylation of glycogen synthase kinase-3β and the microtubule-associated protein tau in the hippocampus and cerebellum of female rat. J Neurosci Res 2011; 90:878-86. [DOI: 10.1002/jnr.22808] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 08/25/2011] [Accepted: 09/01/2011] [Indexed: 01/26/2023]
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17
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Amorim MA, Guerra-Araiza C, Garcia-Segura LM. Progesterone as a regulator of phosphorylation in the central nervous system. Horm Mol Biol Clin Investig 2010; 4:601-7. [DOI: 10.1515/hmbci.2010.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 10/05/2010] [Indexed: 11/15/2022]
Abstract
AbstractProgesterone exerts a variety of actions in the central nervous system under physiological and pathological conditions. As in other tissues, progesterone acts in the brain through classical progesterone receptors and through alternative mechanisms. Here, we review the role of progesterone as a regulator of kinases and phosphatases, such as extracellular-signal regulated kinases, phosphoinositide 3-kinase, Akt, glycogen synthase kinase 3, protein phosphatase 2A and phosphatase and tensin homolog deleted on chromosome 10. In addition, we analyzed the effects of progesterone on the phosphorylation of Tau, a protein that is involved in microtubule stabilization in neurons.
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Guerra-Araiza C, Amorim MA, Pinto-Almazán R, González-Arenas A, Campos MG, Garcia-Segura LM. Regulation of the phosphoinositide-3 kinase and mitogen-activated protein kinase signaling pathways by progesterone and its reduced metabolites in the rat brain. J Neurosci Res 2009; 87:470-81. [DOI: 10.1002/jnr.21848] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Estradiol modulates functional brain organization during the menstrual cycle: an analysis of interhemispheric inhibition. J Neurosci 2009; 28:13401-10. [PMID: 19074013 DOI: 10.1523/jneurosci.4392-08.2008] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
According to the hypothesis of progesterone-mediated interhemispheric decoupling (Hausmann and Güntürkün, 2000), functional cerebral asymmetries (FCAs), which are stable in men and change during the menstrual cycle in women, are generated by interhemispheric inhibition of the dominant on the nondominant hemisphere. The change of lateralization during the menstrual cycle in women might indicate that sex hormones play an important role in modulating FCAs. We used functional magnetic resonance imaging to examine the role of estradiol in determining cyclic changes of interhemispheric inhibition. Women performed a word-matching task, while they were scanned twice during the cycle, once during the menstrual and once during the follicular phase. By use of a connectivity analysis we found that the inhibitory influence of left-hemispheric language areas on homotopic areas of the right hemisphere is strongest during the menses, resulting in a pronounced lateralization. During the follicular phase, due to rising estradiol levels, inhibition and thus functional cerebral asymmetries are reduced. These results reveal a powerful neuromodulatory action of estradiol on the dynamics of functional brain organization in the female brain. They may further contribute to the ongoing discussion of sex differences in brain function in that they help explain the dynamic part of functional brain organization in which the female differs from the male brain.
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Valente SG, Marques RH, Baracat EC, Cavalheiro EA, Naffah-Mazzacoratti MG, Amado D. Effect of hormonal replacement therapy in the hippocampus of ovariectomized epileptic female rats using the pilocarpine experimental model. Epilepsy Res 2008; 82:46-56. [PMID: 18760902 DOI: 10.1016/j.eplepsyres.2008.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Revised: 07/03/2008] [Accepted: 07/08/2008] [Indexed: 01/01/2023]
Abstract
Amado and Cavalheiro [Amado, D., Cavalheiro, E.A., 1998. Hormonal and gestational parameters in female rats submitted to the pilocarpine model of epilepsy. Epilepsy Res. 32, 266-274], studying the establishment of the pilocarpine epilepsy model in female rats observed that the estrous cycle was dramatically altered during the three periods of this experimental model. This work was delineated to study the function of sexual hormones in the development of the epilepsy model induced by pilocarpine in ovariectomized rats. Experimental groups were: (a) control animals during estrus phase of the estrous cycle (E) and ovariectomized female rats (OVX) treated with saline instead of pilocarpine in the same volume, (b) experimental animals, that developed status epilepticus (SE) and were studied during the chronic phase of this model: intact chronic rats (CHRON) and ovariectomized chronic rats (OVX+CHRON) and (c) ovariectomized chronic rats, that were submitted to hormonal replacement therapy treated with: medroxyprogesterone (OVX+CHRON+MPA); 17beta-estradiol (OVX+CHRON+E2), or both (OVX+CHRON+E2+MPA). All ovariectomized animals showed genital atrophy 4 days after the surgical procedure. Moreover, all animals that developed SE and survived showed spontaneous recurrent seizures during the chronic phase. Concerning to seizure frequency, animals receiving medroxyprogesterone associated with 17beta-estradiol showed decreased seizures' number. However, animals that received only medroxyprogesterone therapy also showed reduction in the number of seizures. In addition, hormonal treatment was also able to stabilize the mossy fibers sprouting process, showing the importance of these hormones in the development of the epilepsy in female rats.
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Affiliation(s)
- S G Valente
- Departamento de Neurologia e Neurocirurgia - Disciplina de Neurologia Experimental, Brazil; Departamento de Ortopedia e Traumatologia - Escola Paulista de Medicina/Universidade Federal de São Paulo, Brazil
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Ramirez VD, Dluzen DE, Ke FC. Effects of progesterone and its metabolites on neuronal membranes. CIBA FOUNDATION SYMPOSIUM 2007; 153:125-41; discussion 141-4. [PMID: 2292209 DOI: 10.1002/9780470513989.ch7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Evidence supporting a membrane site of action for progesterone includes the rapidity of its effects when directly infused into tissue containing mainly nerve terminals, the absence of functional intracellular progesterone receptors in vitro and the fact that progesterone conjugated to bovine serum albumin (BSA) in the C-3 position (P-3-BSA) activates the release of hypothalamic luteinizing hormone releasing hormone (LHRH) or modulates amphetamine-evoked striatal dopamine release. In addition, P2 membrane fractions from different areas of the CNS but not P1 fractions or P2 membranes from peripheral progesterone targets have specific binding sites for P-11-125I-BSA. Among several BSA-conjugated steroids tested for competition displacement P-3-BSA had the highest affinity with an estimated inhibition constant of 28.5 +/- 2.1 nM. This binding depends on the presence of cations such as Ca2+ and Mg2+ and after chemical depolarization of the P2 membranes the binding curve of P-3-BSA shifts to the right. While progesterone is effective in releasing LHRH from the hypothalamus, 5 beta-pregnan-3 beta-ol-20-one (a 5 beta reduced metabolite) is at least 1000-fold more potent than the parent compound when tested in vitro and in vivo. This action is indirect because tetrodotoxin at 10(-6) M blocks the LHRH releasing action, although 5 beta-prenan-3 beta-ol-20-one is still capable of releasing noradrenaline. Although 5 beta-pregnan-3 beta-ol-20-one can replace progesterone in activating the LHRH neural apparatus this is not true for the nigro-striatal dopamine system where only progesterone or P-3-BSA is effective, an action which is also indirect since tetrodotoxin blocks the effect of either compound. These results indicate that progesterone acts at membrane sites to modulate specific functions of the CNS and that site-specific mechanisms exist within the CNS which may differentially control its conversion to more active compounds.
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Affiliation(s)
- V D Ramirez
- Department of Physiology and Biophysics, University of Illinois, Urbana 61801
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22
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Lambert JJ, Peters JA, Sturgess NC, Hales TG. Steroid modulation of the GABAA receptor complex: electrophysiological studies. CIBA FOUNDATION SYMPOSIUM 2007; 153:56-71; discussion 71-82. [PMID: 1963400 DOI: 10.1002/9780470513989.ch4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effect of some endogenous and synthetic steroids on the operation of inhibitory and excitatory amino acid neurotransmitter receptors was examined. Anaesthetic pregnane steroids (e.g. alphaxalone, 5 alpha-pregnan-3 alpha-ol-20-one, 5 alpha-pregnane-3 alpha,21-diol-20-one) potentiated GABAA receptor-mediated whole-cell currents recorded from bovine chromaffin cells. The threshold concentration for enhancement was 10-30 nM. Potentiation was stereoselective and was mediated by a steroid-induced prolongation of the burst duration of the GABA-activated channel. Additionally, the pregnane steroids directly activated the GABAA receptor. Both the potentiation and activation appear to be mediated through a site(s) distinct from the well-known barbiturate and benzodiazepine allosteric sites of the GABAA receptor. Intracellularly applied alphaxalone and 5 beta-pregnan-3 alpha-ol-20-one had no discernible effects on the GABAA receptor, suggesting that the steroid binding site can only be accessed extracellularly. Unlike behaviourally depressant barbiturates, which modulate GABAA receptor function in a manner similar to that of the pregnane steroids, alphaxalone and 5 beta-pregnan-3 alpha-ol-20-one show striking pharmacological selectivity. Voltage-clamp recordings from rat central neurons in culture indicate that pentobarbitone exerts its potentiating and GABA-mimetic effects over a range of concentrations which also depress currents mediated by glutamate receptor subtypes. In contrast, alphaxalone and several endogenous steroids greatly enhance responses to GABA, but have no direct effect on glutamate receptors. Such pharmacological selectivity, coupled with appropriate stereoselectivity of action, suggests that the GABAA receptor mediates some of the behavioural effects of synthetic and endogenous pregnane steroids.
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Affiliation(s)
- J J Lambert
- Department of Pharmacology & Clinical Pharmacology, Ninewells Hospital & Medical School, Dundee University, UK
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Guerra-Araiza C, Amorim MAR, Camacho-Arroyo I, Garcia-Segura LM. Effects of progesterone and its reduced metabolites, dihydroprogesterone and tetrahydroprogesterone, on the expression and phosphorylation of glycogen synthase kinase-3 and the microtubule-associated protein tau in the rat cerebellum. Dev Neurobiol 2007; 67:510-20. [PMID: 17443805 DOI: 10.1002/dneu.20383] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Progesterone exerts a variety of actions in the brain, where it is rapidly metabolized to 5alpha-dihydroprogesterone (DHP) and 3alpha,5alpha-tetrahydroprogesterone (THP). The effect of progesterone and its metabolites on the expression and phosphorylation of the microtubule-associated protein Tau and glycogen synthase kinase 3beta (GSK3beta), a kinase involved in Tau phosphorylation, were assessed in two progesterone-sensitive brain areas: the hypothalamus and the cerebellum. Administration of progesterone, DHP, and THP to ovariectomized rats did not affect Tau and GSK3beta assessed in whole hypothalamic homogenates. In contrast, progesterone and its metabolites resulted in a significant decrease in the expression of Tau and GSK3beta in the cerebellum. Furthermore, progesterone administration resulted in an increase in the phosphorylation of two epitopes of Tau (Tau-1 and PHF-1) phosphorylated by GSK3beta, but did not affect the phosphorylation of an epitope of Tau (Ser262) that is GSK3beta insensitive. These effects were accompanied by a decrease in the phosphorylation of GSK3beta in serine, which is associated to an increase in its activity, suggesting that the effect of progesterone on Tau-1 and PHF-1 phosphorylation in the cerebellum is mediated by GSK3beta. The regulation of Tau expression and phosphorylation by progesterone may contribute to the hormonal regulation of cerebellar function by the modification of neuronal cytoskeleton.
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Wallner M, Hanchar HJ, Olsen RW. Low dose acute alcohol effects on GABA A receptor subtypes. Pharmacol Ther 2006; 112:513-28. [PMID: 16814864 PMCID: PMC2847605 DOI: 10.1016/j.pharmthera.2006.05.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Accepted: 05/15/2006] [Indexed: 12/23/2022]
Abstract
GABA(A) receptors (GABA(A)Rs) are the main inhibitory neurotransmitter receptors and have long been implicated in mediating at least part of the acute actions of ethanol. For example, ethanol and GABAergic drugs including barbiturates and benzodiazepines share many pharmacological properties. Besides the prototypical synaptic GABA(A)R subtypes, nonsynaptic GABA(A)Rs have recently emerged as important regulators of neuronal excitability. While high doses (> or =100 mM) of ethanol have been reported to enhance activity of most GABA(A)R subtypes, most abundant synaptic GABA(A)Rs are essentially insensitive to ethanol concentrations that occur during social ethanol consumption (< 30 mM). However, extrasynaptic delta and beta3 subunit-containing GABA(A)Rs, associated in the brain with alpha4 or alpha6 subunits, are sensitive to low millimolar ethanol concentrations, as produced by drinking half a glass of wine. Additionally, we found that a mutation in the cerebellar alpha6 subunit (alpha6R100Q), initially reported in rats selectively bred for increased alcohol sensitivity, is sufficient to produce increased alcohol-induced motor impairment and further increases of alcohol sensitivity in recombinant alpha6beta3delta receptors. Furthermore, the behavioral alcohol antagonist Ro15-4513 blocks the low dose alcohol enhancement on alpha4/6/beta3delta receptors, without reducing GABA-induced currents. In binding assays alpha4beta3delta GABA(A)Rs bind [(3)H]Ro15-4513 with high affinity, and this binding is inhibited, in an apparently competitive fashion, by low ethanol concentrations, as well as analogs of Ro15-4513 that are active to antagonize ethanol or Ro15-4513's block of ethanol. We conclude that most low to moderate dose alcohol effects are mediated by alcohol actions on alcohol/Ro15-4513 binding sites on GABA(A)R subtypes.
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Affiliation(s)
| | | | - Richard W. Olsen
- Corresponding author. Tel.: +1 310 825 5093; fax: +1 310 267 2003. (R.W. Olsen)
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25
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Bäckström T, Wahlström G, Wahlström K, Zhu D, Wang MD. Isoallopregnanolone; an antagonist to the anaesthetic effect of allopregnanolone in male rats. Eur J Pharmacol 2005; 512:15-21. [PMID: 15814085 DOI: 10.1016/j.ejphar.2005.01.049] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Accepted: 01/27/2005] [Indexed: 11/18/2022]
Abstract
The interaction of isoallopregnanolone (3 beta-OH-5 alpha-pregnan-20-one) on allopregnanolone (3 alpha-OH-5 alpha-pregnan-20-one) induced anaesthesia was studied in male rats using burst suppression of 1 s ("silent second") with an electroencephalographic-threshold method. The i.v. administration of isoallopregnanolone was varied in relation to induction of "silent second". Pre-treatment with isoallopregnanolone (12.5-50 mg/kg iv) 2 min prior to the threshold test gave an increase in the threshold dose of allopregnanolone (ANOVA df(3;36), F=13.61, P<0.001), which was dose dependent (r=0.73, b [slope]=0.08, df=38, P<0.001). After isoallopregnanolone pre-treatment, but not in the controls, anaesthesia time was positively related to the dose of allopregnanolone (r=0.52, b=1.72, df=28, P<0.01). Anaesthesia times were not influenced by a corresponding administration of isoallopregnanolone immediately after induction of "silent second". When allopregnanolone and isoallopregnanolone were infused together at molar ratios of 1:1, 1:1.23, 1:1.43, a linear increase of the threshold doses of allopregnanolone was seen in relation to the dose of isoallopregnanolone (r=0.86, b=0.40, df=8, P<0.01). Thus isoallopregnanolone can antagonise the anaesthetic action of allopregnanolone.
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Affiliation(s)
- Torbjörn Bäckström
- Umeå Neurosteroid Research Center, Department of Clinical Science, Obstetrics and Gynaecology, Norrlands University Hospital, Umeå University, Umeå, Sweden.
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26
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Sex hormonal modulation of hemispheric asymmetries in the attentional blink. J Int Neuropsychol Soc 2005; 11:263-72. [PMID: 15892902 DOI: 10.1017/s1355617705050319] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2003] [Revised: 01/10/2004] [Indexed: 11/07/2022]
Abstract
The present study examines differences in functional cerebral asymmetries modulated by gonadal steroid hormones during the menstrual cycle in women. Twenty-one right-handed women with regular menstrual cycles performed a double-stream rapid serial visual presentation (RSVP) task, with one stream in each visual field, during the low steroid menses and the high steroid midluteal phase. They were required to detect a target item, and then a probe item, each of which could appear in either stream. If the probe item appeared 200 ms after the target, detection of the probe was impaired-a phenomenon known as the "attentional blink." This occurred in both streams in the midluteal phase, but only in the right visual field during menses. Thus low steroid levels appeared to restrict the attentional blink to the left hemisphere, while high levels of estradiol and progesterone in the midluteal phase appeared to reduce functional asymmetries by selectively increasing the attentional blink in the right hemisphere. This effect appears to be mediated by estradiol rather than progesterone, and it is compatible with the assumption of a hormone-related suppression of right hemisphere functions during the midluteal phase.
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Sanna E, Talani G, Busonero F, Pisu MG, Purdy RH, Serra M, Biggio G. Brain steroidogenesis mediates ethanol modulation of GABAA receptor activity in rat hippocampus. J Neurosci 2005; 24:6521-30. [PMID: 15269263 PMCID: PMC6729881 DOI: 10.1523/jneurosci.0075-04.2004] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An interaction with the GABA type A (GABA(A)) receptor has long been recognized as one of the main neurochemical mechanisms underlying many of the pharmacological actions of ethanol. However, more recent data have suggested that certain behavioral and electrophysiological actions of ethanol are mediated by an increase in brain concentration of neuroactive steroids that results from stimulation of the hypothalamic-pituitary-adrenal (HPA) axis. Neuroactive steroids such as 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha,5alpha-THP) are, in fact, potent and efficacious endogenous positive modulators of GABA(A) receptor function. Because neurosteroids can be synthesized de novo in the brain, we have investigated whether ethanol might affect both neurosteroid synthesis and GABA(A) receptor function in isolated rat hippocampal tissue. Here, we show that ethanol increases the concentration of 3alpha,5alpha-THP as well as the amplitude of GABA(A) receptor-mediated IPSCs recorded from CA1 pyramidal neurons in isolated hippocampal slices. These effects are shared by the neurosteroid precursor progesterone, the peripheral benzodiazepine receptor-selective agonist CB34, and gamma-hydroxybutyrate, all of which are known to increase the formation of neuroactive steroids in plasma and in the brain. The action of ethanol on GABA(A) receptor-mediated IPSC amplitude is biphasic, consisting of a rapid, direct effect on GABA(A) receptor activity and an indirect effect that appears to be mediated by neurosteroid synthesis. Furthermore, ethanol affects GABA(A) receptor activity through a presynaptic action, an effect that is not dependent on neurosteroid formation. These observations suggest that ethanol may modulate GABA(A) receptor function through an increase in de novo neurosteroid synthesis in the brain that is independent of the HPA axis. This novel mechanism may have a crucial role in mediating specific central effects of ethanol.
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Affiliation(s)
- Enrico Sanna
- Department of Experimental Biology, Section of Neuroscience, University of Cagliari, 09123 Cagliari, Italy.
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Hsu FC, Smith SS. Progesterone withdrawal reduces paired-pulse inhibition in rat hippocampus: dependence on GABA(A) receptor alpha4 subunit upregulation. J Neurophysiol 2003; 89:186-98. [PMID: 12522171 PMCID: PMC2887349 DOI: 10.1152/jn.00195.2002] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Withdrawal from the endogenous steroid progesterone (P) after chronic administration increases anxiety and seizure susceptibility via declining levels of its potent GABA-modulatory metabolite 3alpha-OH-5alpha-pregnan-20-one (3alpha,5alphaTHP). This 3alpha,5alpha-THP withdrawal also results in a decreased decay time constant for GABA-gated current assessed using whole cell patch-clamp techniques on pyramidal cells acutely dissociated from CA1 hippocampus. The purpose of this study was to test the hypothesis that the decreases in total integrated GABA-gated current observed at the level of the isolated pyramidal cell would be manifested as a reduced GABA inhibition at the circuit level following hormone withdrawal. Toward this end, adult, female rats were administered P via subcutaneous capsule for 3 wk using a multiple withdrawal paradigm. We then evaluated paired-pulse inhibition (PPI) of pyramidal neurons in CA1 hippocampus using extracellular recording techniques in hippocampal slices from rats 24 h after removal of the capsule (P withdrawal, P Wd). The population spike (PS) was recorded at the stratum pyramidale following homosynaptic orthodromic stimulation in the nearby stratum radiatum. The threshold for eliciting a response was decreased after P Wd, and the mean PS amplitude was significantly increased compared with control values at this time. Paired pulses with 10-ms inter-pulse intervals were then applied across an intensity range from 2 to 20 times threshold. Evaluation of paired-pulse responses showed a significant 40-50% reduction in PPI for PS recorded in the hippocampal CA1 region after P Wd, suggesting an increase in circuit excitability. At this time, enhancement of PPI by the benzodiazepine lorazepam (LZM; 10 microM) was prevented, while pentobarbital (10 microM) potentiation of PPI was comparable to control levels of response. These data are consistent with upregulation of the alpha4 subunit of the GABA(A) receptor (GABAR) as we have previously shown. Moreover, the reduced PPI caused by P Wd was prevented by suppression of GABAR alpha4-subunit expression following intraventricular administration of specific antisense oligonucleotides (1 microg/h for 72 h). These results demonstrating a reduction in PPI following P Wd suggest that GABAergic-mediated recurrent or feed-forward inhibition occurring at the circuit level were decreased following P Wd in female rats, an effect at least partially attributable to alterations in the GABAR subunit gene expression.
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Affiliation(s)
- Fu-Chun Hsu
- Pediatric Regional Epilepsy Program and Joseph Stokes Research Institute of The Children's Hospital of Philadelphia, Pennsylvania 19104, USA
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Gomez C, Saldivar-Gonzalez A, Delgado G, Rodriguez R. Rapid anxiolytic activity of progesterone and pregnanolone in male rats. Pharmacol Biochem Behav 2002; 72:543-50. [PMID: 12175450 DOI: 10.1016/s0091-3057(02)00722-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The effect of different doses of progesterone (1.0, 3.0, 10.0, 30.0, and 100.0 mg/kg) and pregnanolone (1.0, 3.0, 10.0, and 30.0 mg/kg) upon burying defensive and elevated plus-maze (EPM) tests was investigated in adult male rats and compared with the effects of diazepam (0.25. 0.50, 1.0, and 2.0 mg/kg). All drugs were suspended in a 0.2% methylcellulose solution and administered intraperitoneally 30 min prior to testing. Progesterone and pregnanolone were found to produce anxiolytic-like effects similar to those of diazepam. Thus, at certain doses, both drugs significantly increased the latency for burying and decreased the cumulative burying behavior, without modifying the number of shocks, and increased the time spent in the open arms of the maze, without affecting the spontaneous locomotor activity. These data clearly demonstrate that the defensive burying paradigm is useful to detect the anxiolytic-like properties of pregnanolone. An important finding was that progesterone produces significant behavioral effects 30 min after its administration. This finding suggests a rapid bioconversion of progesterone to its active ring-A reduced metabolites; however, the possibility remains that rapid behavioral effects of progesterone are due to a direct interaction with specific steroid receptors located on the plasma membrane, independently from the gamma-aminobutyric acid(A) (GABA(A)) receptor complex modulation.
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Affiliation(s)
- Claudia Gomez
- Department of Pharmacology, Faculty of Medicine, National University of Mexico, P.O. Box 70-297, Mexico City 04510, Mexico
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Smith SS. Withdrawal properties of a neuroactive steroid: implications for GABA(A) receptor gene regulation in the brain and anxiety behavior. Steroids 2002; 67:519-28. [PMID: 11960630 DOI: 10.1016/s0039-128x(01)00170-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Early work in the field established that the 5 alpha-reduced metabolite of progesterone 3 alpha-OH-5 alpha-pregnan-20-one (allopregnanolone or 3 alpha,5 alpha-THP) is a potent positive modulator of the GABA(A) receptor (GABAR), the receptor mediating the effects of the primary inhibitory transmitter in the brain. This steroid acts in a manner similar to sedative drugs, such as the barbiturates, both in terms of potentiating GABA-induced inhibition in vitro and in behavioral assays, by reducing anxiety and seizure susceptibility. Because sedative compounds exhibit withdrawal properties that result in behavioral hyperexcitability, our laboratory has more recently investigated the effect of prolonged application and rapid removal (i.e. 'withdrawal') of this steroid, administered in vivo to female rats. Withdrawal from 3 alpha,5 alpha-THP produces a state of increased anxiety and lowered seizure threshold, similar to withdrawal from other GABA-modulatory drugs such as the benzodiazepines and alcohol. Hormone withdrawal also produced increases in the alpha 4-containing GABAR, an effect correlated with insensitivity of the GABAR to modulation by the benzodiazepine class of tranquilizers, as would normally occur under control conditions. In addition, changes in intrinsic channel properties, including a marked acceleration in the decay rate was also observed as a result of declining levels of 3 alpha,5 alpha-THP. Such a change would result in less inhibitory total current, and the resulting increase in neuronal excitability could then underlie the observed behavioral excitability following hormone withdrawal. These results suggest that actions of this steroid on a traditional transmitter receptor in the brain lead to alterations in GABAR subunit composition that result in changes in the intrinsic channel properties of the receptor and behavioral excitability. These results may have implications for endogenous fluctuations in this hormone which may accompany premenstrual dysphoric disorder.
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Affiliation(s)
- Sheryl S Smith
- Deppartment of Physiology and Pharmacology, SUNY Health Science Center at Brooklyn, 450 Clarkson Ave., Brooklyn, NY 11203, USA.
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Hausmann M, Güntürkün O. Steroid fluctuations modify functional cerebral asymmetries: the hypothesis of progesterone-mediated interhemispheric decoupling. Neuropsychologia 2000; 38:1362-74. [PMID: 10869579 DOI: 10.1016/s0028-3932(00)00045-2] [Citation(s) in RCA: 173] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
This study examines the modulation of functional cerebral asymmetries by gonadal hormones in three distinct groups. Young, normally cycling women performed a prototypical left (lexical decision) and two prototypical right-hemispheric tasks (figural comparison and face discrimination) during the low steroid menses and the high steroid midluteal phase. Saliva progesterone levels were measured with radioimmunoassay (RIA). Parallel to younger females, young men, and postmenopausal women were tested at matching time intervals. Results revealed significant interactions between cycle phase and visual half-field in the accuracy of all three tasks for the younger women; stronger lateralization patterns occurring during menses, while a more bilateral or at least less asymmetric cerebral organization predominated the midluteal phase, when highest levels of progesterone appear. Progesterone seemed to have a significant influence on lateralization in the figural comparison task, with high hormone levels enhancing the performance of the left hemisphere (for this task subdominant), thereby decreasing asymmetry. After menopause, when the levels of gonadal hormones are lower and more stable, the lateralization patterns for all three tasks were similar to those of men and normally cycling women during menses. These results make it likely that steroids and especially progesterone are able to reduce cerebral asymmetries. We hypothesize that progesterone attenuates the effect of glutamate on non-NMDA receptors. This could diminish cortico-cortical transmission which is mostly dependent on a glutamate-induced initial EPSP in pyramidal neurons which receive transcallosal input. The reduction in callosal transfer could then suppress the functional asymmetries.
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Affiliation(s)
- M Hausmann
- AE Biopsychologie, Fakultät für Psychologie, Ruhr-Universität Bochum, D-44780, Bochum, Germany.
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32
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Wang MD, Bäckström T, Landgren S. The inhibitory effects of allopregnanolone and pregnanolone on the population spike, evoked in the rat hippocampal CA1 stratum pyramidale in vitro, can be blocked selectively by epiallopregnanolone. ACTA PHYSIOLOGICA SCANDINAVICA 2000; 169:333-41. [PMID: 10951125 DOI: 10.1046/j.1365-201x.2000.00744.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The progesterone metabolites allopregnanolone (Allo, 3alpha-hydroxy-5alpha-pregnan-20-one) and pregnanolone (Preg, 3alpha-hydroxy-5beta-pregnan-20-one) enhance the gamma-aminobutyric acid (GABA) action through a distinct site on the GABAA-receptor. Their 3beta-isomers epiallopregnanolone (Epiallo, 3beta-hydroxy-5alpha-pregnan-20-one) and epipregnanolone (Epipreg, 3beta-hydroxy-5beta-pregnan-20-one), do not have these effects on GABAA-receptors. We have studied the interaction between Allo/Preg and their 3beta-isomers on action potentials in rat hippocampal slices in vitro. The Schaffer collaterals were stimulated electrically in CA1 striatum radiatum and the population spike (POPSP) was recorded in stratum pyramidale. A 0.5-nL droplet of drug was applied locally onto stratum oriens-pyramidale via a pressure pipett. Muscimol (Mus) (12.5 fmol), Allo and Preg (6.25 fmol) caused a reversible inhibition of POPSP. On the other hand, 6.25 fmol Epiallo had no significant effect on POPSP compared with the vehicle control. Combined Epiallo and Allo application caused a dose-dependent reduction of the Allo inhibition of POPSP. A full blockage was seen at a molar ratio of 1:1. Epiallo also blocked the Preg inhibition of POPSP, when the two drugs were combined in a molar ratio of 1:1. Epiallo did not block the Mus inhibition of POPSP, when the two drugs were combined at a molar ratio of 1:2. Bath perfusion of 12.5 microM Epiallo blocked the inhibition of 6.25 fmol Allo on POPSP, but not the inhibition caused by 12.5 fmol Mus. Epipreg did not block the inhibition of Allo and Preg on POPSP, when it was combined with the two latter drugs at a molar ratio of 1:1. Our data suggest that the steroid modulation of the GABAA transmitted inhibition of the CA1 pyramidal neurones is selectively and dose dependently blocked by Epiallo, the 3beta-hydroxy-isomer of Allo, but not by Epipreg, the 3beta-hydroxy-isomer of Preg.
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Affiliation(s)
- M D Wang
- Section of Physiology, Department of Integrative Medical Biology, University of Umeâ, Sweden
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Kumon Y, Kim SC, Tompkins P, Stevens A, Sakaki S, Loftus CM. Neuroprotective effect of postischemic administration of progesterone in spontaneously hypertensive rats with focal cerebral ischemia. J Neurosurg 2000; 92:848-52. [PMID: 10794300 DOI: 10.3171/jns.2000.92.5.0848] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Exogenous progesterone has been shown to reduce brain edema and ischemia-induced cell damage and to improve physiological and neurological function during the early stage of focal cerebral ischemia. In the present study, the authors assessed the neuroprotective potential of progesterone during the late stage of ischemia in a transient middle cerebral artery (MCA) occlusion model in the rat. METHODS Forty-eight male spontaneously hypertensive rats were randomly assigned to six groups. Progesterone was dissolved in dimethyl sulfoxide (DMSO). In four groups of rats, the dissolved progesterone (4 mg/kg or 8 mg/kg) was administered for 2 or 7 days after ischemia. In two control groups DMSO was administered for 2 or 7 days after ischemia. Occlusion of the MCA was induced by insertion of an intraluminal suture, and reperfusion was accomplished by withdrawal of the suture. Treatment was initiated on reperfusion, which followed 2 hours of MCA occlusion, and continued once a day. Lesion volume, neurological deficit, and body weight loss were measured 2 or 7 days after ischemia, depending on the animal group. Treatment with a high dose of progesterone (8 mg/kg) resulted in reductions in lesion size, neurological deficits, and body weight, compared with control rats. CONCLUSIONS Administration of progesterone to male rats 2 hours after MCA occlusion reduces ischemic brain damage and improves neurological deficit even 7 days after ischemia.
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Affiliation(s)
- Y Kumon
- Department of Neurosurgery, The University of Oklahoma Health Sciences Center, Oklahoma City, USA.
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Bitran D, Dugan M, Renda P, Ellis R, Foley M. Anxiolytic effects of the neuroactive steroid pregnanolone (3 alpha-OH-5 beta-pregnan-20-one) after microinjection in the dorsal hippocampus and lateral septum. Brain Res 1999; 850:217-24. [PMID: 10629767 DOI: 10.1016/s0006-8993(99)02150-2] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The anxiolytic effects of the neuroactive steroid, 3 alpha-OH-5 beta-pregnan-20-one (pregnanolone), were determined after injection into the dorsal hippocampus or lateral septum in adult male rats. An increase in the proportion of time spent on the open arms of the elevated plus-maze was found after 2.5 and 5 micrograms of pregnanolone in the hippocampus, but not in the lateral septum. Intrahippocampal injection of 2.5 micrograms of the 3 beta-epimer of pregnanolone did not affect behavior in the plus-maze; a higher dose of 5 micrograms produced an anxiogenic effect. In the shock-probe burying test latency to burying behavior was increased by intrahippocampal or intraseptal injection of 2.5 and 5 micrograms of pregnanolone; the duration of burying behavior was decreased by 0.5, 2.5 and 5 micrograms of pregnanolone injection in the dorsal hippocampus or lateral septum. The number of contacts with the shock probe was not affected by any dose of pregnanolone in either intracranial site of injection. The anxiolytic effects of intrahippocampal or intraseptal injection of pregnanolone were blocked by intracranial pretreatment with 20 ng of picrotoxin, but not by microinjection of 5 micrograms of flumazenil or 200 ng of PK 11195. Thus, inhibition of the hippocampus, mediated by the pregnanolone's action at the GABAA receptor, produces a general anxiolytic effect. However, similar inhibition in the lateral septum attenuates active avoidance of anxiogenic stimuli (i.e., decreased burying behavior), but not passive avoidance of aversive stimuli (i.e., exploration of open arms of the plus-maze and number of shocks in the probe burying test).
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Affiliation(s)
- D Bitran
- Department of Psychology, College of the Holy Cross, Worcester, MA 01610, USA.
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Fernández-Guasti A, Picazo O. Sexual differentiation modifies the allopregnanolone anxiolytic actions in rats. Psychoneuroendocrinology 1999; 24:251-67. [PMID: 10101732 DOI: 10.1016/s0306-4530(98)00048-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The administration of progesterone (0.0, 1.0 and 2.0 mg/rat, s.c.) and allopregnanolone (5 alpha, 3 alpha dihydroprogesterone) (0.0, 0.5 and 1.0 mg/rat, s.c.) to both, males and females, produced a similar reduction in burying behavior. Only allopregnanolone showed a gender-dependent effect on burying behavior latency. Allopregnanolone actions were established in five groups of animals according to their neonatal hormonal manipulation: intact males and females, neonatally-testosterone propionate-treated female rats (TP, 30 and 120 micrograms/rat, s.c. at day 5) and neonatally (4-12 h after delivery) castrated males. Males and females showed a reduction in anxiety after treatment with allopregnanolone. Both neonatally-androgenized-females and -castrated males were completely insensitive to allopregnanolone anxiolytic action tested in both burying behavior and plus-maze paradigm. The virilizing action of neonatally administered TP was demonstrated by dose-dependent delayed vaginal opening, a persistent estrus in their vaginal smears and the presence of polifollicular ovaries. Results are discussed on the bases of the differences and similarities between males, females, androgenized females and neonatally castrated males to anxiolytic steroids and the underlying possible processes.
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Bitran D, Carlson D, Leschiner S, Gavish M. Ovarian steroids and stress produce changes in peripheral benzodiazepine receptor density. Eur J Pharmacol 1998; 361:235-42. [PMID: 9865513 DOI: 10.1016/s0014-2999(98)00708-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although past research has described changes in the density of the peripheral benzodiazepine receptor in brain and in peripheral organs in response to stressors and steroid hormone exposure, their combined influence had yet to be determined. This study examined the effect of swim-stress as a function of ovarian hormone administration on the binding of an isoquinoline carboxamide derivative, [3H]PK 11195, in brain and peripheral tissues. In olfactory bulb and adrenal gland, stress increased peripheral benzodiazepine receptor density in ovariectomized rats with and without estradiol and progesterone replacement injection, even when compared with unstressed animals treated with hormones, where estradiol + progesterone decreased peripheral benzodiazepine receptor number in olfactory bulb, but estradiol and estradiol + progesterone increased it in adrenal gland. In frontal cortex, stress decreased peripheral benzodiazepine receptor number, an effect that was reversed by estradiol. In hippocampus estradiol decreased peripheral benzodiazepine receptor density in unstressed animals and estradiol + progesterone decreased peripheral benzodiazepine receptor number in unstressed and stressed animals. In cerebellum, stress, estradiol and estradiol + progesterone alone decreased peripheral benzodiazepine receptor density. In uterus of unstressed controls, estradiol + progesterone increased peripheral benzodiazepine receptor density, and stress produced a further increase in steroid-treated females. Stress did not affect peripheral benzodiazepine receptor density in kidney, except in animals that received estradiol + progesterone injections, where swim-stress produced a significant decrease in peripheral benzodiazepine receptor density. Thus, steroid hormones regulate peripheral benzodiazepine receptor density in endocrine organs and brain, and the hormonal state of the organism modifies the peripheral benzodiazepine receptor response to stress in a tissue- and brain region-specific manner, suggesting that the peripheral benzodiazepine receptor may play a pivotal role in an integrated response to stress.
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Affiliation(s)
- D Bitran
- Department of Psychology, College of the Holy Cross, Worcester, MA, USA.
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Abstract
Pro-convulsant withdrawal properties have been reported for a variety of GABA-modulatory drugs, such as the benzodiazepines (BDZs, [S.E. File, The history of BDZ dependence: a review of animal studies, Neurosci. Biobehav. Rev. 14 (1990) 135-146; P.R. Finley, P. E. Nolan, Precipitation of BDZ withdrawal following sudden discontinuation of midazolam, DICP 23 (1989) 151-152]), barbiturates and ethanol [N. Kokka, D.E. Sapp, U. Witte, R.W. Olsen, Sex differences in sensitivity to pentylenetetrazol but not in GABAA receptor binding, Pharm. Biochem. Behav. 43 (1992) 441-447]. In this report, we test the hypothesis that pro-convulsant effects are produced by withdrawal from the GABA-modulatory neurosteroid 3alpha-OH-5alpha-pregnan-20-one (3alpha,5alpha-THP) after sustained exposure to elevated circulating levels of its parent compound progesterone (P). Seizure activity was precipitated by picrotoxin or with the BDZ inverse agonist n-methyl-beta-carboline-3-carboxamide (beta-CC), and a seizure rating determined 24 h after abrupt discontinuation of P following a multiple withdrawal/chronic administration paradigm. In some cases, a pseudopregnant rat model was employed to produce increased ovarian production of P prior to withdrawal (ovariectomy). Rats undergoing P withdrawal exhibited greater seizure-like activity than vehicle-treated controls, and received seizure scores in the same range as rats undergoing BDZ withdrawal. Administration of a 5alpha-reductase blocker, MK-906, along with P, prevented this pro-convulsant effect of P withdrawal, suggesting that the GABA-modulatory 3alpha,5alpha-THP is the active compound responsible for this withdrawal effect. Combined administration of P and diazepam produced synergistic effects upon withdrawal and produced a seizure score higher than observed after withdrawal from either agent alone. These results suggest that P exhibits withdrawal properties via the neuroactive steroid 3alpha, 5alpha-THP, that include exacerbation of seizure activity. These results may have clinical relevance, as increased incidence and severity of seizures has been reported in susceptible women during times of declining circulating levels of P across the menstrual cycle [T. Backstrom, B. Zetterlund, S. Blom, M. Romano, Effects of intravenous progesterone infusions on the epileptic discharge frequency in women with partial epilepsy, Acta Neurol. Scand. 69 (1984) 240-248; A.G. Herzog, Progesterone therapy in women with complex partial and secondary generalized seizures, Neurology 45 (1995) 1660-1662].
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Affiliation(s)
- M H Moran
- Department of Neurobiology and Anatomy, EPPI, 3200 Henry Ave., Allegheny Univ. of the Health Sciences, Philadelphia, PA 19129, USA
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Janak PH, Redfern JEM, Samson HH. The Reinforcing Effects of Ethanol Are Altered by the Endogenous Neurosteroid, Allopregnanolone. Alcohol Clin Exp Res 1998. [DOI: 10.1111/j.1530-0277.1998.tb03708.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Withdrawal from 3alpha-OH-5alpha-pregnan-20-One using a pseudopregnancy model alters the kinetics of hippocampal GABAA-gated current and increases the GABAA receptor alpha4 subunit in association with increased anxiety. J Neurosci 1998. [PMID: 9651210 DOI: 10.1523/jneurosci.18-14-05275.1998] [Citation(s) in RCA: 268] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In the present study, we have characterized properties of steroid withdrawal using a pseudopregnant rat model. This paradigm results in increased production of endogenous progesterone from ovarian sources and as such is a useful physiological model. "Withdrawal" from progesterone induced by ovariectomy on day 12 of pseudopregnancy resulted in increased anxiety, as determined by a decrease in open arm entries on the elevated plus maze compared to control rats and pseudopregnant animals not undergoing withdrawal. Similar findings were obtained 24 hr after administration of a 5alpha-reductase blocker to a pseudopregnant animal, suggesting that it is the GABAA-modulatory 3alpha-OH-5alpha-pregnan-20-one (3alpha, 5alpha-THP) that produces anxiogenic withdrawal symptoms. Twenty-four hours after steroid withdrawal, the time constant for decay of GABAA-gated current was also reduced sixfold, assessed using whole- cell patch-clamp procedures on pyramidal neurons acutely dissociated from CA1 hippocampus. Thus, 3alpha,5alpha-THP withdrawal results in a marked decrease in total GABAA current, a possible mechanism for its anxiogenic, proconvulsant sequelae. In addition, 3alpha,5alpha-THP withdrawal resulted in insensitivity to the normally potentiating effect of the benzodiazepine lorazepam (LZM) on GABAA-gated Cl- current. This withdrawal profile is similar to that reported for other GABAA-modulatory drugs such as the benzodiazepines (BDZs), barbiturates, and ethanol. These changes were also associated with significant two and threefold increases in both the mRNA and protein for the alpha4 subunit of the GABAA receptor, respectively, in hippocampus. The pseudopregnancy paradigm may be a useful model for periods of endogenous 3alpha,5alpha-THP withdrawal such as premenstrual syndrome and postpartum or postmenopausal dysphoria, when increased emotional lability and BDZ insensitivity have been reported.
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Smith SS, Chapin JK. The estrous cycle and the olivo-cerebellar circuit. I. Contrast enhancement of sensorimotor-correlated cerebellar discharge. Exp Brain Res 1996; 111:371-84. [PMID: 8911931 DOI: 10.1007/bf00228726] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Neuromodulation of Purkinje (Pnj) cell responses by monoamines and estrous hormones is well characterized in the cerebellum at the cellular level, but not at the level of neuronal circuits in the awake behaving animal. In the present study, simultaneous recordings of up to 16 single neurons from within the olivo-cerebellar circuit were obtained through chronically implanted microwire electrode bundles: arrays of Pnj cell like neurons (Pnj cln) in the paravermal cerebellum and neurons within the afferent source of its climbing fiber input, the rostral dorsal accessory olive (rDAO), were recorded simultaneously across 3-20 consecutive estrous cycles during constant or variable speed treadmill locomotion performance tasks. Over 90% of Pnj cln recorded during treadmill locomotion exhibited significant increases (80%) or decreases (10%) in activity correlated with the stance phase of locomotion. In contrast, cells from the rDAO increased activity during speed changes or when the rat failed to maintain the treadmill speed (position slip). On the night of behavioral estrus, which is triggered by elevations in circulating levels of 17 beta-estradiol and progesterone, the magnitude of both increases and decreases in stance-correlated Pnj cln activity increased by 85-115%. These results are consistent with our previous findings that 17 beta-estradiol and progesterone enhance excitatory and inhibitory responses of single Pnj cells to locally applied glutamate and GABA, respectively. This dual enhancement of both excitatory and inhibitory effects, apparently paradoxical at the cellular level, produced a marked heightening of the contrast of the neural population "signal" at the neuronal ensemble level. Furthermore, the stance-correlated discharge of Pnj cln during estrus preceded that during diestrus by approximately 120 ms. Frame-by-frame video analysis also suggested that the swing phase of the step cycle was shortened on estrus compared with diestrus (low hormone state). In addition, rDAO discharge correlated with speed change or position slip was also significantly increased (P < 0.05) on the night of behavioral estrus versus diestrus. Thus, estrus was associated with changes in both the amplitude and the timing of Pnj cln and rDAO discharge correlated with specific behavioral events. These estrous-associated changes in Pnj cell activity were well correlated (r = 0.84) with faster responses to random changes in treadmill speed, a motor performance task. Together, these findings suggest that the increases in the contrast of stance-correlated Phj cln discharge observed following peak circulating levels of sex steroid hormones are associated with improved motor performance on a randomly moving treadmill.
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Affiliation(s)
- S S Smith
- Department of Neurobiology and Anatomy, Medical College of Pennsylvania, Philadelphia 19102-1192, USA.
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Jiang N, Chopp M, Stein D, Feit H. Progesterone is neuroprotective after transient middle cerebral artery occlusion in male rats. Brain Res 1996; 735:101-7. [PMID: 8905174 DOI: 10.1016/0006-8993(96)00605-1] [Citation(s) in RCA: 183] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Progesterone (PROG) is a neurosteroid, possessing a variety of functions in the central nervous system. Exogenous PROG has been shown to reduce secondary neuronal loss in conjunction with attenuated brain edema after cerebral contusion and to reduce brain edema after focal cerebral ischemia. In the present study, we assessed the neuroprotective potential of PROG in a model of focal cerebral ischemia in the rat. Forty-eight male Wistar rats were randomly assigned to 4 groups, i.e. pretreatment with water soluble PROG, or dimethyl sulfoxide (DMSO) dissolved PROG, or DMSO as control or delayed treatment with DMSO dissolved PROG. Middle cerebral artery occlusion (MCAO) was induced by insertion of an intraluminal suture and reperfusion was performed by withdrawing the suture. Pretreatments were initiated 30 min before MCAO via intraperitoneal injection. Delayed treatment was initiated upon reperfusion following 2 h of MCAO. Infarct volume, body weight loss, and neurological deficit were measured 48 h after MCAO. Pre- and delayed treatment with DMSO dissolved PROG resulted in a 39% (P < 0.05) and 34% (P < 0.05) reduction in cerebral infarction, respectively, along with decreased body weight loss and improved neurological function as compared to control animals, whereas no statistically significant reduction in infarct volume by water soluble PROG was found. We demonstrated that administration of PROG to the male rat before or 2 hours after onset of MCAO reduces ischemic cell damage and improves physiological and neurological function 2 days after stroke. These results suggests potential therapeutic properties of PROG in the management of stroke.
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Affiliation(s)
- N Jiang
- Henry Ford Health Science Center, Neurology Department, Detroit, MI 48202, USA
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Abstract
The anteroventral periventricular nucleus (AVPV) is a nodal point in neural circuits regulating secretion of gonadotropin and contains sexually dimorphic populations of hormonally regulated dopamine-, dynorphin-, and enkephalin-containing neurons. Because the tyrosine hydroxylase (TH), prodynorphin (PDYN), and proenkephalin (PENK) genes contain cAMP response elements that control their expression in their promoters, we used histochemical methods to determine whether ovarian steroids alter expression of the cAMP response element-binding protein (CREB) in the AVPV. Because the ability of CREB to activate transcription depends on phosphorylation at Ser133, we also evaluated the effects of acute steroid treatment on levels of phosphorylated CREB (pCREB) in AVPV neurons by using an antibody that differentiates between CREB and pCREB. Treatment of ovariectomized rats with estradiol treatments caused a significant induction in the number of pCREB-immunoreactive nuclei within 30 min that was maintained for at least 4 hr, but did not alter CREB immunostaining in the AVPV. Pretreatment with the estrogen antagonist Nafoxidine blocked this induction. In contrast, acute administration of progesterone to estrogen-primed animals suppressed and then increased pCREB staining in the ASVPV at 30 and 60 min, respectively; no significant differences between experimental and control animals were apparent by 2 hr after progesterone treatment. Double-labeling experiments showed that pCREB was colocalized with PDYN, PENK, or TH mRNA in the AVPV, suggesting that pCREB may mediate the effect of steroid hormones on gene expression in these neurons.
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Frye CA. The neurosteroid 3 alpha, 5 apha-THP has antiseizure and possible neuroprotective effects in an animal model of epilepsy. Brain Res 1995; 696:113-20. [PMID: 8574658 DOI: 10.1016/0006-8993(95)00793-p] [Citation(s) in RCA: 166] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Some anticonvulsant drugs may suppress seizures by enhancing activity of GABAergic systems. Progesterone (P)'s anti-convulsant and neuroprotective effects may be due to the steroid's actions on GABAA-benzodiazepine receptor complexes (GBRs) rather than intracellular progestin receptors (PRs), as many P metabolites have a greater effect in vitro on benzodiazepine binding and Cl-flux than P, but poor affinity for PRs. If P's actions are due to metabolism to a progestin more potent at GBRs, then systemic administration of one of those P metabolites should also prevent CNS damage. To test this hypothesis male rats were implanted with a bipolar electrode, aimed above the perforant pathway. Experimental animals received the 5 alpha-reduced P metabolite most effective at GBRs, 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP) 2.5 mg/kg s.c., 3 h prior to perforant pathway stimulation, while control animals received sesame oil vehicle. The duration of chewing and drooling and the incidence of wet dog shakes, partial and full seizures were reduced during perforant pathway stimulation in animals pre-treated with 3 alpha,5 alpha-THP compared to vehicle. Two weeks later, animals pre-treated with 3 alpha,5 alpha-THP had shorter latencies and distances to find a hidden platform in a Morris Water maze task. 3 alpha,5 alpha-THP pre-treatment also reduced damage to CA1 and CA3 layers of the hippocampus and preserved the number of neurons in the hilar region. These data indicate that the neurosteroid metabolite of P, 3 alpha,5 alpha-THP, can have anticonvulsant and may have neuroprotective effects in an animal model of epilepsy. Further, these data suggest that the mechanism of P's protective and anticonvulsant effects may be via GBRs rather than PRs.
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Affiliation(s)
- C A Frye
- Psychology Department, Bates College, Lewiston, ME 04240, USA
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Costa AM, Spence KT, Plata-Salamán CR, ffrench-Mullen JM. Residual Ca2+ channel current modulation by megestrol acetate via a G-protein alpha s-subunit in rat hypothalamic neurones. J Physiol 1995; 487 ( Pt 2):291-303. [PMID: 8558464 PMCID: PMC1156573 DOI: 10.1113/jphysiol.1995.sp020880] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
1. The inhibition of voltage-activated Ca2+ channel currents by the orally active progesterone derivative, megestrol acetate (MA), was examined in freshly dissociated rat ventromedial hypothalamic nucleus (VMN) neurones using the whole-cell voltage-clamp technique with 10 mM Ba2+ as the charge carrier. 2. The steady-state inhibition of the peak high-threshold Ca2+ channel current evoked by depolarization from -80 to -10 mV by MA increased in a concentration-dependent fashion. MA inhibited a fraction of the whole-cell Ca2+ channel current while progesterone had no effect on the peak Ca2+ channel current (7% at 10 microM). The low-threshold Ca2+ (T-type) current, evoked from -100 to -30 mV, was unaffected by MA. 3. Intracellular dialysis with MA had no effect on the Ca2+ channel current. Concomitant extracellular perfusion of MA showed normal inhibitory activity, suggesting that the MA binding site can only be accessed extracellularly. 4. The high-threshold Ca2+ channel current in VMN neurones was found to consist of four pharmacologically distinguishable components: an N-type current, an L-type current, a P-type current, and a residual current. MA had no effect on the N-, L- and P-type Ca2+ channel currents, but inhibited the residual current. 5. In neurones isolated from cholera toxin-treated animals, the MA-induced inhibition of the Ca2+ channel current was significantly diminished, suggesting a G-protein alpha S-subunit involvement. 6. Treatment with antisense phosphothio-oligodeoxynucleotides to the G alpha S-subunit (antisense-G alpha S) significantly reduced the MA-induced inhibition of the Ca2+ channel current. Treatment with either sense-G alpha S or antisense-G alpha 11 had no effect, confirming a G alpha S-subunit involvement. 7. These results suggest that appetite enhancement induced by MA in cachectic patients may in part be due to a novel central nervous system action, that is, inhibition of a fraction of the whole-cell Ca2+ channel current to attenuate the firing of VMN neurones that may be involved in satiety mechanisms.
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Affiliation(s)
- A M Costa
- Department of Pharmacology, Zeneca Pharmaceuticals, Zeneca Inc., Wilmington, DE 19850-5437, USA
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45
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Landgren S, Selstam G. Interaction between 17 beta-oestradiol and 3 alpha-hydroxy-5 alpha-pregnane-20-one in the control of neuronal excitability in slices from the CA1 hippocampus in vitro of guinea-pigs and rats. ACTA PHYSIOLOGICA SCANDINAVICA 1995; 154:165-76. [PMID: 7572212 DOI: 10.1111/j.1748-1716.1995.tb09898.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effect of 17 beta-oestradiol and 3 alpha-hydroxy-5 alpha-pregnane-20-one (allopregnanolone) on the action potentials in the Schaffer collateral pathway was investigated in hippocampus CA1. Slices from male and female guinea-pigs and female rats were used. In the rat three groups were studied: (a) untreated prepubertal rats at day 25 after partus; (b) rats injected on day 26 with 10 IU of equine serum gonadotropin studied on day 28, when in the pro-oestrus follicular phase; and (c) on day 32 when in the luteal phase. The allopregnanolone (12.6 microM, 0.5 nL) was applied locally in stratum orienspyramidale. the 17 beta-oestradiol (0.7 nM) was perfused (4 mL min-1) or applied locally. The amplitude of the population spike in stratum pyramidale was increased by oestradiol in guinea-pigs of both sexes and in all the three groups of rats. Allopregnanolone decreased the amplitude of the population spike in the guinea-pigs and in the luteal phase rats. The effect appeared within seconds after the application of the drugs. The allopregnanolone inhibition of the population spike was increased by perfusion with oestradiol in the guinea-pigs and in the luteal phase rats. This effect appeared within 7 min, and improved with increasing length of the perfusion (7-71 min). It remained for 55 min after return to perfusion with artificial cerebrospinal fluid. In prepubertal and follicular phase rats the allopregnanolone inhibition was seen only after perfusion with oestradiol for more than 15 min. The results show that 17 beta-oestradiol increases the allopregnanolone inhibition and that this inhibition is most efficient during the luteal phase of the rat.
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Affiliation(s)
- S Landgren
- Department of Physiology, University of Umeå, Sweden
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Smith SS. Female sex steroid hormones: from receptors to networks to performance--actions on the sensorimotor system. Prog Neurobiol 1994; 44:55-86. [PMID: 7831472 DOI: 10.1016/0301-0082(94)90057-4] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- S S Smith
- Department of Anatomy, Hahnemann University, Philadelphia, Pennsylvania 19102-1192
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Meyer JH, Gruol DL. Dehydroepiandrosterone sulfate alters synaptic potentials in area CA1 of the hippocampal slice. Brain Res 1994; 633:253-61. [PMID: 8137159 DOI: 10.1016/0006-8993(94)91546-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The influences of the neurosteroid dehydroepiandrosterone sulfate (DHEAS) on neuronal properties and synaptic transmission in area CA1 of the hippocampus were examined using a slice preparation. DHEAS had no apparent effects upon cell membrane resistance or active cell responses to intracellular hyperpolarizing or depolarizing current pulses. However, DHEAS did increase the excitability of CA1 neurons in response to Schaffer collateral synaptic stimulation. This was apparent both in field potential recordings as well as intracellular recordings. Effects appeared within minutes following exposure to DHEAS and were reversible, suggesting a non-genomic mechanism of action. Intracellular recordings indicated that DHEAS increased the amplitudes of EPSPs associated with stimulation of Schaffer collateral fibers. The increased EPSP amplitudes resulted from DHEAS effecting an inhibition of fast IPSPs as well as a direct enhancement of excitatory synaptic transmission. No significant effects on slow IPSPs were noted. In summary, neurosteroids such as DHEAS may influence synaptic transmission through multiple mechanisms. Such influences result in increased excitability of postsynaptic neurons and indicate the profound influences neurosteroids may have to regulate neuronal activity in intact CNS structures.
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Affiliation(s)
- J H Meyer
- Scripps Research Institute, Department of Neuropharmacology, La Jolla, CA 92037
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Gallo MA, Smith SS. Progesterone withdrawal decreases latency to and increases duration of electrified prod burial: a possible rat model of PMS anxiety. Pharmacol Biochem Behav 1993; 46:897-904. [PMID: 7906038 DOI: 10.1016/0091-3057(93)90219-j] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The purpose of this study was to determine whether withdrawal from chronic exposure to the female sex steroid progesterone (P) alters response of female rats to an electrified prod using the defensive burying paradigm, considered a rat model of anxiety. Withdrawal from chronic exposure to 500 micrograms P (daily, SC, for four days) resulted in a significant decrease in the latency (77%, P < 0.05) to prod burial and an increase in duration (75%, P < 0.05) of this reflexive response, compared with the behavior of oil-injected controls. These results are consistent with the idea that withdrawal from chronic exposure to P increases behaviors that accompany anxiety. At a lower dose (50 micrograms), withdrawal from chronically administered P produced significant changes in response to this paradigm only when the steroid was given concomitantly with estradiol (2 micrograms, SC, for two days). Prior exposure to indomethacin, which blocks the conversion of P to its metabolite 3 alpha,5 alpha-tetrahydroprogesterone (3-alpha-hydroxy-5-alpha-pregnan-20-one), prevented P withdrawal from altering response in the defensive burying paradigm. This finding suggests that it may be withdrawal from this metabolite, rather than P, which increases behaviors associated with increased anxiety.
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Affiliation(s)
- M A Gallo
- Department of Anatomy, Hahnemann University, Philadelphia, PA 19102-1192
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Taubøll E, Gjerstad L. Comparison of 5 alpha-pregnan-3 alpha-ol-20-one and phenobarbital on cortical synaptic activation and inhibition studied in vitro. Epilepsia 1993; 34:228-35. [PMID: 8453930 DOI: 10.1111/j.1528-1157.1993.tb02403.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effects of 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha-OH-DHP) and phenobarbital (PB) on synaptic excitation and inhibition in rat hippocampal slices in vitro were compared. Stimulations were made orthodromically and antidromically while we recorded extracellularly from the dendritic and the somatic layer of the CA1 region. Perfusion with 5 micrograms/ml of 3 alpha-OH-DHP for 30 min significantly increased the recurrent inhibition evoked by antidromic stimulation. The effect was most pronounced at short interstimulus intervals. The duration of the recurrent inhibition also was prolonged. There was no effect on the conditioned population spike after orthodromic paired-pulse stimulation. Furthermore, no effect was observed on the amplitude of the orthodromic fiber volley, the rate of increase in the field excitatory postsynaptic potential (EPSP) and the latency and amplitude of the CA1 population spike. Qualitative and quantitative similar findings were observed during perfusion with PB 0.1 mg/ml, (i.e., a concentration 20 times higher than that of 3 alpha-OH-DHP). Higher concentrations of PB also affected synaptic excitation. The findings suggest a similar effect of 3 alpha-OH-DHP and PB on recurrent GABA-ergic inhibition; however, 3 alpha-OH-DHP appears to be much more potent.
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Affiliation(s)
- E Taubøll
- Department of Neurology, Rikshospitalet, National Hospital, University of Oslo, Norway
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Taubøll E, Lindström S. The effect of progesterone and its metabolite 5 alpha-pregnan-3 alpha-ol-20-one on focal epileptic seizures in the cat's visual cortex in vivo. Epilepsy Res 1993; 14:17-30. [PMID: 8449176 DOI: 10.1016/0920-1211(93)90071-e] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The acute effects of progesterone and its brain metabolite 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha-OH-DHP) on focal epileptic seizures in the cat's visual cortex was studied in vivo using an unanesthetized cervaux-isolé preparation. This model made it possible to study in parallel the effect of the drugs on ictal activity and synaptic transmission. A dose-dependent increase in seizure threshold was observed after i.v. injections of both 3 alpha-OH-DHP and progesterone, 3 alpha-OH-DHP being about 20 times as potent as the latter. I.v. injections of 3 alpha-OH-DHP 1.0 mg/kg increased the median seizure threshold to 265% of baseline. While 3 alpha-OH-DHP exerted an immediate effect on seizure thresholds, the maximal effect of progesterone was delayed about 20 min. Concerning the mechanisms underlying the antiepileptic effect, three changes occurred within the effective dose range: (1) a small, but significant reduction in the presynaptic nerve volleys, (2) a reduction in the postsynaptic excitatory field potentials in the dorsal lateral geniculate nucleus and cortex, and (3) an enhanced postsynaptic inhibition. Taken together, these observations point to both pre- and postsynaptic effects, supporting the hypothesis of a barbiturate-like mechanism of action of progesterone and its brain metabolites.
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Affiliation(s)
- E Taubøll
- Department of Neurology, Rikshospitalet, National Hospital, University of Oslo, Norway
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