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Moores G, Liu K, Pikula A, Bui E. Fertility treatment for people with epilepsy. Pract Neurol 2024:pn-2023-003922. [PMID: 38408862 DOI: 10.1136/pn-2023-003922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2024] [Indexed: 02/28/2024]
Abstract
Fertility treatment, including assisted reproductive technology (ART), is increasingly used. Sex hormones influence seizure control as well as interacting with antiseizure medications, and so the hormonal manipulation involved in fertility treatments has direct implications for people with epilepsy. Here, we summarise the various fertility treatments and consider their important influences on epilepsy care. While early observations raised concerns about seizure exacerbation associated with ART, there are limited data to guide best practice in people with epilepsy, and further research is needed.
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Affiliation(s)
- Ginette Moores
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Kimberly Liu
- Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada
| | - Aleksandra Pikula
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada
| | - Esther Bui
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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Echevarria-Cooper DM, Kearney JA. Evaluating the interplay between estrous cyclicity and flurothyl-induced seizure susceptibility in Scn2a K1422E mice. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000850. [PMID: 38162411 PMCID: PMC10757737 DOI: 10.17912/micropub.biology.000850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 10/30/2023] [Accepted: 12/12/2023] [Indexed: 01/03/2024]
Abstract
Recently, we demonstrated that Scn2a K1422E female mice showed a distinct distribution of flurothyl-induced seizure thresholds. To evaluate whether the estrous cycle contributes to this effect, estrous cycle monitoring was performed in mice that had undergone ovariectomy, sham surgery, or no treatment prior to seizure induction. Ovariectomy did not affect the non-unimodal distribution of flurothyl seizure thresholds observed in Scn2a K1422E females. Additionally, seizure thresholds were not associated with estrous cycle stage in mice that underwent sham surgery or in non-surgerized (intact) mice. Interestingly, intact Scn2a K1422E females showed evidence of disrupted estrous cyclicity, an effect not previously described in a genetic epilepsy model.
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3
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Lawande NV, Conklin EA, Christian‐Hinman CA. Sex and gonadectomy modify behavioral seizure susceptibility and mortality in a repeated low-dose kainic acid systemic injection paradigm in mice. Epilepsia Open 2023; 8:1512-1522. [PMID: 37715318 PMCID: PMC10690657 DOI: 10.1002/epi4.12828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 09/12/2023] [Indexed: 09/17/2023] Open
Abstract
OBJECTIVE Sex differences in epilepsy appear driven in part due to effects of gonadal steroids, with varying results in experimental models based on species, strain, and method of seizure induction. Furthermore, removing the main source of these steroids via gonadectomy may impact seizure characteristics differently in males and females. Repeated low-dose kainic acid (RLDKA) systemic injection paradigms were recently shown to reliably induce status epilepticus (SE) and hippocampal histopathology in C57BL/6J mice. Here, we investigated whether seizure susceptibility in a RLDKA injection protocol exhibits a sex difference and whether gonadectomy differentially influences response to this seizure induction paradigm in males and females. METHODS Adult C57BL/6J mice were left gonad-intact as controls or gonadectomized (females: ovariectomized, OVX; males: orchidectomized, ORX). At least 2 weeks later, KA was injected ip, every 30 minutes at 7.5 mg/kg or less until the animal reached SE, defined by at least 5 generalized seizures (GS, Racine stage 3 or higher). Parameters of susceptibility to GS induction, SE development, and mortality rates were quantified. RESULTS No differences in seizure susceptibility or mortality were observed between control males and control females. Gonadectomized mice exhibited increased susceptibility and reduced latency to both GS and SE in comparison to corresponding controls of the same sex, but the effects were stronger in males. In addition, ORX males, but not OVX females, exhibited strongly increased seizure-induced mortality. SIGNIFICANCE The RLDKA protocol is notable for its efficacy in inducing SE and seizure-induced histopathology in C57BL/6J mice, the background for many transgenic strains in current use in epilepsy research. The present results indicate that this protocol may be beneficial for investigating the effects of gonadal hormone replacement on seizure susceptibility, mortality, and seizure-induced histopathology, and that gonadectomy unmasks sex differences in susceptibility to seizures and mortality not observed in gonad-intact controls.
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Affiliation(s)
- Niraj V. Lawande
- Department of Molecular and Integrative PhysiologyUniversity of Illinois Urbana‐ChampaignUrbanaIllinoisUSA
| | | | - Catherine A. Christian‐Hinman
- Department of Molecular and Integrative PhysiologyUniversity of Illinois Urbana‐ChampaignUrbanaIllinoisUSA
- Neuroscience ProgramUniversity of Illinois Urbana‐ChampaignUrbanaIllinoisUSA
- Beckman Institute for Advanced Science and TechnologyUniversity of Illinois Urbana‐ChampaignUrbanaIllinoisUSA
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Carvalho V, Colonna I, Curia G, Ferretti MT, Arabia G, Molnar MJ, Lebedeva ER, Moro E, de Visser M, Bui E. Sex steroid hormones and epilepsy: Effects of hormonal replacement therapy on seizure frequency of postmenopausal women with epilepsy-A systematic review. Eur J Neurol 2023; 30:2884-2898. [PMID: 37326003 DOI: 10.1111/ene.15916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/29/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND AND PURPOSE Hormonal replacement therapy (HRT) is used for symptomatic treatment of menopause. Some evidence suggests a proconvulsant effect of estrogen and an anticonvulsant role of progesterone. Thus, the use of exogenous sex steroid hormones might influence the course of epilepsy in peri- and postmenopausal women with epilepsy (WWE). We conducted a systematic review on the impact of HRT on the frequency of seizures of WWE. METHODS PubMed and Scopus were searched for articles published from inception until August 2022. Abstracts from the past 5 years from the European Academy of Neurology and European Epilepsy Congresses were also reviewed. Article reference lists were screened, and relevant articles were retrieved for consultation. Interventional and observational studies on WWE and animal models of estrogen deficiency were included. Critical appraisal was performed using the revised Cochrane risk-of-bias tool for randomized trials and ROBINS-E tool. RESULTS Of 497 articles screened, 13 studies were included, including three human studies. One cross-sectional study showed a decrease in seizure frequency in WWE using combined HRT, a case-control study showed an increase in comparison with controls, and a randomized clinical trial found a dose-dependent increase in seizure frequency in women with focal epilepsy taking combined HRT. Ten studies addressing the impact of HRT in rat models were also included, which showed conflicting results. CONCLUSIONS There is scarce evidence of the impact of HRT in WWE. Further studies should evaluate the harmful potential, and prospective registries are needed for monitoring this population.
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Affiliation(s)
- Vanessa Carvalho
- Department of Neurosciences and Mental Health, Hospital de Santa Maria, Lisbon, Portugal
- Instituto de Medicina Molecular Professor João Lobo Antunes, Lisbon, Portugal
- Centro de Estudos Egas Moniz, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
| | - Isabella Colonna
- Complex Operative Unit of Neurology, "F. Ferrari" Hospital, Casarano, Italy
| | - Giulia Curia
- Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | | | - Gennarina Arabia
- Institute of Neurology, University Magna Graecia, Catanzaro, Italy
| | - Maria Judit Molnar
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
| | - Elena R Lebedeva
- Department of Neurology, Ural State Medical University, International Medical Center "Europe-Asia" Yekaterinburg, Yekaterinburg, Russia
| | - Elena Moro
- CHU Grenoble Alpes, Division of Neurology, Movement Disorders Unit, Grenoble Institute of Neurosciences, Grenoble Alpes University, Grenoble, France
| | - Marianne de Visser
- Department of Neurology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Esther Bui
- Division of Neurology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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5
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Lawande NV, Conklin EA, Christian-Hinman CA. Sex and gonadectomy modify behavioral seizure susceptibility and mortality in a repeated low-dose kainic acid systemic injection paradigm in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541824. [PMID: 37292790 PMCID: PMC10245840 DOI: 10.1101/2023.05.22.541824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Objective Sex differences in epilepsy appear driven in part due to effects of gonadal steroids, with varying results in experimental models based on species, strain, and method of seizure induction. Furthermore, removing a main source of these steroids via gonadectomy may impact seizure characteristics differently in males and females. Repeated low-dose kainic acid (RLDKA) systemic injection paradigms were recently shown to reliably induce status epilepticus (SE) and hippocampal histopathology in C57BL/6J mice. Here, we investigated whether seizure susceptibility in a RLDKA injection protocol exhibits a sex difference, and whether gonadectomy differentially influences response to this seizure induction paradigm in males and females. Methods Adult C57BL/6J mice were left gonad-intact as controls or gonadectomized (females: ovariectomized, OVX; males: orchidectomized, ORX). At least 2 weeks later, KA was injected i.p. every 30 minutes at 7.5 mg/kg or less until the animal reached SE, defined by at least 5 generalized seizures (GS, Racine stage 3 or higher). Parameters of susceptibility to GS induction, SE development, and mortality rates were quantified. Results No differences in seizure susceptibility or mortality were observed between control males and control females. ORX males exhibited increased susceptibility and reduced latency to both GS and SE, but OVX females exhibited increased susceptibility and reduced latency to SE only. However, ORX males, but not OVX females, exhibited strongly increased seizure-induced mortality. Significance The RLDKA protocol is notable for its efficacy in inducing SE and seizure-induced histopathology in C57BL/6J mice, the background for many transgenic strains in current use in epilepsy research. The present results indicate that this protocol may be beneficial for investigating the effects of gonadal hormone replacement on seizure susceptibility, mortality, and seizure-induced histopathology, and that gonadectomy unmasks sex differences in susceptibility to seizures and mortality not observed in gonad-intact controls.
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Affiliation(s)
- Niraj V. Lawande
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL, 61801 USA
| | - Elisabeth A. Conklin
- Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, IL, 61801 USA
| | - Catherine A. Christian-Hinman
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL, 61801 USA
- Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, IL, 61801 USA
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL, 61801 USA
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Echevarria-Cooper DM, Kearney JA. Evaluating the interplay between estrous cyclicity and induced seizure susceptibility in Scn2aK1422E mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.27.538584. [PMID: 37163100 PMCID: PMC10168397 DOI: 10.1101/2023.04.27.538584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Pathogenic variants in SCN2A are associated with a range of neurodevelopmental disorders (NDD). SCN2A-related NDD show wide phenotypic heterogeneity, suggesting that modifying factors must be considered in order to properly elucidate the mechanisms of pathogenic variants. Recently, we characterized neurological phenotypes in a mouse model of the variant SCN2A-p.K1422E. We demonstrated that heterozygous Scn2aK1422E female mice showed a distinct, reproducible distribution of flurothyl-induced seizure thresholds. Women with epilepsy often show a cyclical pattern of altered seizure susceptibility during specific phases of the menstrual cycle which can be attributed to fluctuations in hormones and corresponding changes in neurosteroid levels. Rodent models have been used extensively to examine the relationship between the estrous (menstrual) cycle, steroid hormones, and seizure susceptibility. However, the effects of the estrous cycle on seizure susceptibility have not been evaluated in the context of an epilepsy-associated genetic variant. To determine whether the estrous cycle affects susceptibility to flurothyl-induced seizures in Scn2aK1422E female mice, estrous cycle monitoring was performed in mice that had undergone ovariectomy (OVX), sham surgery, or no treatment prior to seizure induction. Removing the influence of circulating sex hormones via OVX did not affect the non-unimodal distribution of flurothyl seizure thresholds observed in Scn2aK1422E females. Additionally, flurothyl seizure thresholds were not associated with estrous cycle stage in mice that underwent sham surgery or were untreated. These data suggest that variation in Scn2aK1422E flurothyl seizure threshold is not significantly influenced by the estrous cycle and, by extension, fluctuations in ovarian hormones. Interestingly, untreated Scn2aK1422E females showed evidence of disrupted estrous cyclicity, an effect not previously described in a genetic epilepsy model. This unexpected result highlights the importance of considering sex specific effects and the estrous cycle in support of more inclusive biomedical research.
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Affiliation(s)
- Dennis M. Echevarria-Cooper
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Chicago, IL 60611, USA
| | - Jennifer A. Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Chicago, IL 60611, USA
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Dal Pai J, da Silva JC, Sanabria V, Amorim RP, Predebon G, Cossa AC, Trindade-Filho E, Amado D. Non-Status Epilepticus female rats show seizure-like behaviors in the chronic phase of Pilocarpine experimental model. BRAZ J BIOL 2023; 83:e237412. [DOI: 10.1590/1519-6984.237412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 06/04/2021] [Indexed: 11/22/2022] Open
Abstract
Abstract Only few studies have focus on animals that received Pilocarpine (Pilo) and did not develop behavioral status epilepticus (SE) and, whether they may become epileptic in the model’s chronic phase. Previews works observed mossy fiber sprouting in the hippocampus of Non-SE (NSE) rats, while others observed spontaneous and recurrent seizures (SRS) 6 - 8 months after animals received Pilo. It is known that neuronal excitability is influenced by female hormones, as well as, the occurrence of SE in castrated and non-castrated female rats. However, it is not known whether females that received Pilo and did not show SE, may have SRS. The aim of this work was to investigate whether castrated and non-castrated female rats that did not show behavioral SE after Pilo, will develop SRS in the following one-year. For that, animals received 360 mg/kg of Pilo and were video monitored for 12 months. SE females from castrated and non-castrated groups became epileptic since the first month after drug injection. Epileptic behaviors were identified watching video monitoring recordings in the fast speed. Castrated and Non-castrated NSE animals showed behaviors resembling seizures described by Racine Scale stages 1 - 3. Motor alterations showed by NSE groups could be observed only when recordings were analyzed in slow speed. In addition, behavioral manifestations as, rhythmic head movements, sudden head movements, whole body movements and immobility were also observed in both, SE and NSE groups. We concluded that NSE female rats may have become epileptic. Adding to it, slow speed analysis of motor alterations was essential for the observation of NSE findings, which suggests that possibly many motor alterations have been underestimated in epilepsy experimental research.
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Affiliation(s)
- J. Dal Pai
- Universidade Federal de São Paulo, Brasil
| | - J. C. da Silva
- Universidade Estadual de Ciências da Saúde de Alagoas, Brasil; Centro Universitário CESMAC, Brasil
| | | | | | | | | | - E. Trindade-Filho
- Universidade Estadual de Ciências da Saúde de Alagoas, Brasil; Centro Universitário CESMAC, Brasil
| | - D. Amado
- Universidade Federal de São Paulo, Brasil
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Pacheco ALD, de Melo IS, de Araujo Costa M, Amaral MMC, de Gusmão Taveiros Silva NK, Santos YMO, Gitaí DLG, Duzzioni M, Borbely AU, Silva RS, Donatti ALF, Mestriner L, Fuzo CA, Cummings RD, Garcia-Cairasco N, Dias-Baruffi M, de Castro OW. Neuroprotective Effect of Exogenous Galectin-1 in Status Epilepticus. Mol Neurobiol 2022; 59:7354-7369. [PMID: 36171480 DOI: 10.1007/s12035-022-03038-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 09/19/2022] [Indexed: 10/14/2022]
Abstract
Intrahippocampal pilocarpine microinjection (H-PILO) induces status epilepticus (SE) that can lead to spontaneous recurrent seizures (SRS) and neurodegeneration in rodents. Studies using animal models have indicated that lectins mediate a variety of biological activities with neuronal benefits, especially galectin-1 (GAL-1), which has been identified as an effective neuroprotective compound. GAL-1 is associated with the regulation of cell adhesion, proliferation, programmed cell death, and immune responses, as well as attenuating neuroinflammation. Here, we administrated GAL-1 to Wistar rats and evaluated the severity of the SE, neurodegenerative and inflammatory patterns in the hippocampal formation. Administration of GAL-1 caused a reduction in the number of class 2 and 4 seizures, indicating a decrease in seizure severity. Furthermore, we observed a reduction in inflammation and neurodegeneration 24 h and 15 days after SE. Overall, these results suggest that GAL-1 has a neuroprotective effect in the early stage of epileptogenesis and provides new insights into the roles of exogenous lectins in temporal lobe epilepsy (TLE).
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Affiliation(s)
- Amanda Larissa Dias Pacheco
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Igor Santana de Melo
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Maisa de Araujo Costa
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Mariah Morais Celestino Amaral
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Nívea Karla de Gusmão Taveiros Silva
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Yngrid Mickaelli Oliveira Santos
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Daniel Leite Góes Gitaí
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Marcelo Duzzioni
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Alexandre Urban Borbely
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Robinson Sabino Silva
- Department of Physiology, Institute of Biomedical Sciences, Federal University of Uberlândia (UFU), Uberlândia, MG, Brazil
| | - Ana Luiza Ferreira Donatti
- Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil.,Department of Neuroscience and Behavioral Sciences, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Luisa Mestriner
- Department of Clinical Analyses, Toxicology, and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Carlos Alessandro Fuzo
- Department of Clinical Analyses, Toxicology, and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Richard D Cummings
- Beth Israel Deaconess Medical Center, Department of Surgery, Harvard Glycomics Center, Harvard Medical School, CLS 11087 - 3 Blackfan Circle, Boston, MA, 02115, USA
| | - Norberto Garcia-Cairasco
- Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil.,Department of Neuroscience and Behavioral Sciences, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Marcelo Dias-Baruffi
- Department of Clinical Analyses, Toxicology, and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil.
| | - Olagide Wagner de Castro
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil.
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9
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Hophing L, Kyriakopoulos P, Bui E. Sex and gender differences in epilepsy. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 164:235-276. [PMID: 36038205 DOI: 10.1016/bs.irn.2022.06.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Sex and gender differences in epilepsy are important influencing factors in epilepsy care. In epilepsy, the hormonal differences between the sexes are important as they impact specific treatment considerations for patients at various life stages particularly during early adulthood with establishment of the menstrual cycle, pregnancy, perimenopause and menopause. Choice of antiseizure medication may have direct consequences on hormonal cycles, hormonal contraception, pregnancy and fetal risk of major congenital malformation. Conversely hormones whether intrinsic or extrinsically administered may have direct impact on antiseizure medications and seizure control. This chapter explores these important influences on the management of persons with epilepsy.
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Affiliation(s)
- Lauren Hophing
- Krembil Brain Institute, University Health Network, University of Toronto, Toronto, Canada
| | | | - Esther Bui
- Krembil Brain Institute, University Health Network, University of Toronto, Toronto, Canada.
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10
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Walters JM, Kim EC, Zhang J, Jeong HG, Bajaj A, Baculis B, Tracy G, Ibrahim B, Christian-Hinman CA, Llano DA, Huesmann GR, Chung HJ. Pharmacological inhibition of STriatal-Enriched protein tyrosine Phosphatase by TC-2153 reduces hippocampal excitability and seizure propensity. Epilepsia 2022; 63:1211-1224. [PMID: 35188269 PMCID: PMC9586517 DOI: 10.1111/epi.17192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 12/30/2021] [Accepted: 02/01/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVE STriatal-Enriched protein tyrosine Phosphatase (STEP) is a brain-specific tyrosine phosphatase. Membrane-bound STEP61 is the only isoform expressed in hippocampus and cortex. Genetic deletion of STEP enhances excitatory synaptic currents and long-term potentiation in the hippocampus. However, whether STEP61 affects seizure susceptibility is unclear. Here we investigated the effects of STEP inhibitor TC-2153 on seizure propensity in a murine model displaying kainic acid (KA)-induced status epilepticus and its effect on hippocampal excitability. METHODS Adult male and female C57BL/6J mice received intraperitoneal injection of either vehicle (2.8% dimethylsulfoxide [DMSO] in saline) or TC-2153 (10 mg/kg) and then either saline or KA (30 mg/kg) 3 h later before being monitored for behavioral seizures. A subset of female mice was ovariectomized (OVX). Acute hippocampal slices from Thy1-GCaMP6s mice were treated with either DMSO or TC-2153 (10 μM) for 1 h, and then incubated in artificial cerebrospinal fluid (ACSF) and potassium chloride (15 mM) for 2 min prior to live calcium imaging. Pyramidal neurons in dissociated rat hippocampal culture (DIV 8-10) were pre-treated with DMSO or TC-2153 (10 µM) for 1 h before whole-cell patch-clamp recording. RESULTS TC-2153 treatment significantly reduced KA-induced seizure severity, with greater trend seen in female mice. OVX abolished this TC-2153-induced decrease in seizure severity in female mice. TC-2153 application significantly decreased overall excitability of acute hippocampal slices from both sexes. Surprisingly, TC-2153 treatment hyperpolarized resting membrane potential and decreased firing rate, sag voltage, and hyperpolarization-induced current (Ih ) of cultured hippocampal pyramidal neurons. SIGNIFICANCE This study is the first to demonstrate that pharmacological inhibition of STEP with TC-2153 decreases seizure severity and hippocampal activity in both sexes, and dampens hippocampal neuronal excitability and Ih . We propose that the antiseizure effects of TC-2153 are mediated by its unexpected action on suppressing neuronal intrinsic excitability.
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Affiliation(s)
- Jennifer M. Walters
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Eung Chang Kim
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jiaren Zhang
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Han Gil Jeong
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Archit Bajaj
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Brian Baculis
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Gregory Tracy
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Baher Ibrahim
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Catherine A. Christian-Hinman
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Daniel A. Llano
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Graham R. Huesmann
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Neurology, Carle Foundation Hospital, Urbana, IL, USA
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Hee Jung Chung
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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11
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Echevarria-Cooper DM, Hawkins NA, Misra SN, Huffman AM, Thaxton T, Thompson CH, Ben-Shalom R, Nelson AD, Lipkin AM, George AL, Bender KJ, Kearney JA. Cellular and behavioral effects of altered NaV1.2 sodium channel ion permeability in Scn2aK1422E mice. Hum Mol Genet 2022; 31:2964-2988. [PMID: 35417922 PMCID: PMC9433730 DOI: 10.1093/hmg/ddac087] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/28/2022] [Accepted: 04/09/2022] [Indexed: 11/13/2022] Open
Abstract
Genetic variants in SCN2A, encoding the NaV1.2 voltage-gated sodium channel, are associated with a range of neurodevelopmental disorders with overlapping phenotypes. Some variants fit into a framework wherein gain-of-function missense variants that increase neuronal excitability lead to developmental and epileptic encephalopathy, while loss-of-function variants that reduce neuronal excitability lead to intellectual disability and/or autism spectrum disorder (ASD) with or without co-morbid seizures. One unique case less easily classified using this framework is the de novo missense variant SCN2A-p.K1422E, associated with infant-onset developmental delay, infantile spasms and features of ASD. Prior structure–function studies demonstrated that K1422E substitution alters ion selectivity of NaV1.2, conferring Ca2+ permeability, lowering overall conductance and conferring resistance to tetrodotoxin (TTX). Based on heterologous expression of K1422E, we developed a compartmental neuron model incorporating variant channels that predicted reductions in peak action potential (AP) speed. We generated Scn2aK1422E mice and characterized effects on neurons and neurological/neurobehavioral phenotypes. Cultured cortical neurons from heterozygous Scn2aK1422E/+ mice exhibited lower current density with a TTX-resistant component and reversal potential consistent with mixed ion permeation. Recordings from Scn2aK1442E/+ cortical slices demonstrated impaired AP initiation and larger Ca2+ transients at the axon initial segment during the rising phase of the AP, suggesting complex effects on channel function. Scn2aK1422E/+ mice exhibited rare spontaneous seizures, interictal electroencephalogram abnormalities, altered induced seizure thresholds, reduced anxiety-like behavior and alterations in olfactory-guided social behavior. Overall, Scn2aK1422E/+ mice present with phenotypes similar yet distinct from other Scn2a models, consistent with complex effects of K1422E on NaV1.2 channel function.
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Affiliation(s)
- Dennis M Echevarria-Cooper
- Departments of Pharmacology, Northwestern University Feinberg School of Medicine; Chicago, IL, USA 60611.,Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Chicago, IL, USA, 60611
| | - Nicole A Hawkins
- Departments of Pharmacology, Northwestern University Feinberg School of Medicine; Chicago, IL, USA 60611
| | - Sunita N Misra
- Departments of Pharmacology, Northwestern University Feinberg School of Medicine; Chicago, IL, USA 60611.,Departments of Pediatrics, Northwestern University Feinberg School of Medicine; Chicago, IL, USA 60611.,Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA 60611
| | - Alexandra M Huffman
- Departments of Pharmacology, Northwestern University Feinberg School of Medicine; Chicago, IL, USA 60611
| | - Tyler Thaxton
- Departments of Pharmacology, Northwestern University Feinberg School of Medicine; Chicago, IL, USA 60611
| | - Christopher H Thompson
- Departments of Pharmacology, Northwestern University Feinberg School of Medicine; Chicago, IL, USA 60611
| | - Roy Ben-Shalom
- Mind Institute and Department of Neurology, University of California, Davis, Sacramento, CA, United States 95817
| | - Andrew D Nelson
- Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA 94158
| | - Anna M Lipkin
- Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA 94158.,Neuroscience Graduate Program, University of California, San Francisco, CA, USA 94158
| | - Alfred L George
- Departments of Pharmacology, Northwestern University Feinberg School of Medicine; Chicago, IL, USA 60611.,Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Chicago, IL, USA, 60611
| | - Kevin J Bender
- Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA 94158
| | - Jennifer A Kearney
- Departments of Pharmacology, Northwestern University Feinberg School of Medicine; Chicago, IL, USA 60611.,Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Chicago, IL, USA, 60611
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12
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Christian CA, Reddy DS, Maguire J, Forcelli PA. Sex Differences in the Epilepsies and Associated Comorbidities: Implications for Use and Development of Pharmacotherapies. Pharmacol Rev 2021; 72:767-800. [PMID: 32817274 DOI: 10.1124/pr.119.017392] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The epilepsies are common neurologic disorders characterized by spontaneous recurrent seizures. Boys, girls, men, and women of all ages are affected by epilepsy and, in many cases, by associated comorbidities as well. The primary courses of treatment are pharmacological, dietary, and/or surgical, depending on several factors, including the areas of the brain affected and the severity of the epilepsy. There is a growing appreciation that sex differences in underlying brain function and in the neurobiology of epilepsy are important factors that should be accounted for in the design and development of new therapies. In this review, we discuss the current knowledge on sex differences in epilepsy and associated comorbidities, with emphasis on those aspects most informative for the development of new pharmacotherapies. Particular focus is placed on sex differences in the prevalence and presentation of various focal and generalized epilepsies; psychiatric, cognitive, and physiologic comorbidities; catamenial epilepsy in women; sex differences in brain development; the neural actions of sex and stress hormones and their metabolites; and cellular mechanisms, including brain-derived neurotrophic factor signaling and neuronal-glial interactions. Further attention placed on potential sex differences in epilepsies, comorbidities, and drug effects will enhance therapeutic options and efficacy for all patients with epilepsy. SIGNIFICANCE STATEMENT: Epilepsy is a common neurological disorder that often presents together with various comorbidities. The features of epilepsy and seizure activity as well as comorbid afflictions can vary between men and women. In this review, we discuss sex differences in types of epilepsies, associated comorbidities, pathophysiological mechanisms, and antiepileptic drug efficacy in both clinical patient populations and preclinical animal models.
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Affiliation(s)
- Catherine A Christian
- Department of Molecular and Integrative Physiology, Neuroscience Program, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois (C.A.C.); Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas (D.S.R.); Neuroscience Department, Tufts University School of Medicine, Boston, Massachusetts (J.M.); and Departments of Pharmacology and Physiology and Neuroscience, Georgetown University, Washington, D.C. (P.A.F.)
| | - Doodipala Samba Reddy
- Department of Molecular and Integrative Physiology, Neuroscience Program, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois (C.A.C.); Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas (D.S.R.); Neuroscience Department, Tufts University School of Medicine, Boston, Massachusetts (J.M.); and Departments of Pharmacology and Physiology and Neuroscience, Georgetown University, Washington, D.C. (P.A.F.)
| | - Jamie Maguire
- Department of Molecular and Integrative Physiology, Neuroscience Program, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois (C.A.C.); Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas (D.S.R.); Neuroscience Department, Tufts University School of Medicine, Boston, Massachusetts (J.M.); and Departments of Pharmacology and Physiology and Neuroscience, Georgetown University, Washington, D.C. (P.A.F.)
| | - Patrick A Forcelli
- Department of Molecular and Integrative Physiology, Neuroscience Program, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois (C.A.C.); Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas (D.S.R.); Neuroscience Department, Tufts University School of Medicine, Boston, Massachusetts (J.M.); and Departments of Pharmacology and Physiology and Neuroscience, Georgetown University, Washington, D.C. (P.A.F.)
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13
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Li J, Leverton LK, Naganatanahalli LM, Christian-Hinman CA. Seizure burden fluctuates with the female reproductive cycle in a mouse model of chronic temporal lobe epilepsy. Exp Neurol 2020; 334:113492. [PMID: 33007292 DOI: 10.1016/j.expneurol.2020.113492] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/22/2020] [Accepted: 09/28/2020] [Indexed: 12/30/2022]
Abstract
Women with catamenial epilepsy often experience increased seizure burden near the time of ovulation (periovulatory) or menstruation (perimenstrual). To date, a rodent model of chronic temporal lobe epilepsy (TLE) that exhibits similar endogenous fluctuations in seizures has not been identified. Here, we investigated whether seizure burden changes with the estrous cycle in the intrahippocampal kainic acid (IHKA) mouse model of TLE. Adult female IHKA mice and saline-injected controls were implanted with EEG electrodes in the ipsilateral hippocampus. At one and two months post-injection, 24/7 video-EEG recordings were collected and estrous cycle stage was assessed daily. Seizures were detected using a custom convolutional neural network machine learning process. Seizure burden was compared within each mouse between diestrus and combined proestrus and estrus days (pro/estrus) at two months post-injection. IHKA mice showed higher seizure burden on pro/estrus compared with diestrus, characterized by increased time in seizures and longer seizure duration. When all IHKA mice were included, no group differences were observed in seizure frequency or EEG power. However, increased baseline seizure burden on diestrus was correlated with larger cycle-associated differences, and when analyses were restricted to mice that showed the severe epilepsy typical of the IHKA model, increased seizure frequency on pro/estrus was also revealed. Controls showed no differences in EEG parameters with cycle stage. These results suggest that the stages of proestrus and estrus are associated with higher seizure burden in IHKA mice. The IHKA model may thus recapitulate at least some aspects of reproductive cycle-associated seizure clustering.
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Affiliation(s)
- Jiang Li
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Leanna K Leverton
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Laxmi Manisha Naganatanahalli
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Catherine A Christian-Hinman
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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14
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Yousuf H, Smies CW, Hafenbreidel M, Tuscher JJ, Fortress AM, Frick KM, Mueller D. Infralimbic Estradiol Enhances Neuronal Excitability and Facilitates Extinction of Cocaine Seeking in Female Rats via a BDNF/TrkB Mechanism. Front Behav Neurosci 2019; 13:168. [PMID: 31417375 PMCID: PMC6684748 DOI: 10.3389/fnbeh.2019.00168] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/11/2019] [Indexed: 11/13/2022] Open
Abstract
Women are more susceptible to developing cocaine dependence than men, but paradoxically, are more responsive to treatment. The potent estrogen, 17β-estradiol (E2), mediates these effects by augmenting cocaine seeking but also promoting extinction of cocaine seeking through E2's memory-enhancing functions. Although we have previously shown that E2 facilitates extinction, the neuroanatomical locus of action and underlying mechanisms are unknown. Here we demonstrate that E2 infused directly into the infralimbic-medial prefrontal cortex (IL-mPFC), a region critical for extinction consolidation, enhances extinction of cocaine seeking in ovariectomized (OVX) female rats. Using patch-clamp electrophysiology, we show that E2 may facilitate extinction by potentiating intrinsic excitability of IL-mPFC neurons. Because the mnemonic effects of E2 are known to be regulated by brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase B (TrkB), we examined whether BDNF/TrkB signaling was necessary for E2-induced enhancement of excitability and extinction. We found that E2-mediated increases in excitability of IL-mPFC neurons were abolished by Trk receptor blockade. Moreover, blockade of TrkB signaling impaired E2-facilitated extinction of cocaine seeking in OVX female rats. Thus, E2 enhances IL-mPFC neuronal excitability in a TrkB-dependent manner to support extinction of cocaine seeking. Our findings suggest that pharmacological enhancement of E2 or BDNF/TrkB signaling during extinction-based therapies would improve therapeutic outcome in cocaine-addicted women.
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Affiliation(s)
- Hanna Yousuf
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Chad W Smies
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Madalyn Hafenbreidel
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Jennifer J Tuscher
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Ashley M Fortress
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Karyn M Frick
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Devin Mueller
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, United States.,Department of Biological Sciences, Kent State University, Kent, OH, United States
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15
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Estrogen-Dominant Ovarian Cycle Stages Are Associated with Neural Network Dysfunction and Cognitive and Behavioral Deficits in the hAPP-J20 Mouse Model of Alzheimer's Disease. eNeuro 2019; 6:6/3/ENEURO.0179-19.2019. [PMID: 31147386 PMCID: PMC6565846 DOI: 10.1523/eneuro.0179-19.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 05/14/2019] [Indexed: 01/30/2023] Open
Abstract
Highlighted Research Paper:Ovarian Cycle Stages Modulate Alzheimer-Related Cognitive and Brain Network Alterations in Female Mice, by Lauren Broestl, Kurtresha Worden, Arturo J. Moreno, Emily J. Davis, Dan Wang, Bayardo Garay, Tanya Singh, Laure Verret, Jorge J. Palop, and Dena B. Dubal
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16
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Iqbal R, Ahmed S, Jain GK, Vohora D. Design and development of letrozole nanoemulsion: A comparative evaluation of brain targeted nanoemulsion with free letrozole against status epilepticus and neurodegeneration in mice. Int J Pharm 2019; 565:20-32. [PMID: 31051232 DOI: 10.1016/j.ijpharm.2019.04.076] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 04/26/2019] [Accepted: 04/29/2019] [Indexed: 01/08/2023]
Abstract
The target of the current study is to formulate letrozole loaded nanoemulsion (LET-NE) for the direct nose to brain delivery to reduce peripheral effects of letrozole (LET). LET-NE is compared against intraperitoneally administered free LET in kainic acid (KA) induced status epilepticus (SE) in mice. LET loaded nanoemulsion (LET-NE) was prepared by aqueous microtitration method using Triacetin, Tween 80 and PEG-400 as the oil phase, surfactant, and co-surfactant. Nanoemulsion was studied for droplet size, polydispersity index (PDI), zeta potential, percentage transmittance, drug content, surface morphology. TEM images of developed formulation demonstrated spherical droplets with a mean diameter of 95.59 ± 2.34 nm, PDI of 0.162 ± 0.012 and zeta potential of -7.12 ± 0.12 mV respectively. In in-vitro and ex-vivo drug release, LET-NE showed prolonged drug release profile as compared to suspension. SE was induced by KA (10 mg/kg, i.p.) in Swiss albino mice. Behavioral seizure monitoring, biochemical estimations, and histopathological examination were performed. The onset time of SE was significantly enhanced and % incidence of SE was reduced by intranasal administration of LET-NE as compared to KA and LET administered intraperitoneally. Biochemical estimations revealed that LET-NE effectively decreased levels of 17-β estradiol while the levels of 5α-Dihydrotestosterone (5α-DHT) and 3α-androstanediol (3α-Diol) were significantly increased in the hippocampus. In cresyl violet staining LET-NE showed better protection of the hippocampus from neurotoxicity induced by KA as compared to LET. Also, in gamma scintigraphy of mouse brain, intranasal administration of nanoemulsion exhibited the presence of high concentration of LET. The study demonstrates the anticonvulsant and neuroprotective effect of LET-NE probably by inhibition of aromatization of testosterone into 17-β estradiol, proconvulsant, and diverting the pathway into the synthesis of testosterone metabolites, 3α-Diol with known anticonvulsant and neuroprotective action. Brain targeting of LET-NE showed better anticonvulsant and neuroprotective action than LET.
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Affiliation(s)
- Ramsha Iqbal
- Pharmaceutical Medicine, Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Shakeeb Ahmed
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Gaurav K Jain
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Divya Vohora
- Pharmaceutical Medicine, Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India.
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17
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Joshi S, Kapur J. Neurosteroid regulation of GABA A receptors: A role in catamenial epilepsy. Brain Res 2019; 1703:31-40. [PMID: 29481795 PMCID: PMC6107446 DOI: 10.1016/j.brainres.2018.02.031] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 09/08/2017] [Accepted: 02/20/2018] [Indexed: 12/31/2022]
Abstract
The female reproductive hormones progesterone and estrogen regulate network excitability. Fluctuations in the circulating levels of these hormones during the menstrual cycle cause frequent seizures during certain phases of the cycle in women with epilepsy. This seizure exacerbation, called catamenial epilepsy, is a dominant form of drug-refractory epilepsy in women of reproductive age. Progesterone, through its neurosteroid derivative allopregnanolone, increases γ-aminobutyric acid type-A receptor (GABAR)-mediated inhibition in the brain and keeps seizures under control. Catamenial seizures are believed to be a neurosteroid withdrawal symptom, and it was hypothesized that exogenous administration of progesterone to maintain its levels high during luteal phase will treat catamenial seizures. However, in a multicenter, double-blind, phase III clinical trial, progesterone treatment did not suppress catamenial seizures. The expression of GABARs with reduced neurosteroid sensitivity in epileptic animals may explain the failure of the progesterone clinical trial. The expression of neurosteroid-sensitive δ subunit-containing GABARs is reduced, and the expression of α4γ2 subunit-containing GABARs is upregulated, which alters the inhibition of dentate granule cells in epilepsy. These changes reduce the endogenous neurosteroid control of seizures and contribute to catamenial seizures.
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Affiliation(s)
- Suchitra Joshi
- Department of Neurology, University of Virginia, Charlottesville, VA 22908, United States.
| | - Jaideep Kapur
- Department of Neurology, University of Virginia, Charlottesville, VA 22908, United States; Department of Neuroscience, University of Virginia, Charlottesville, VA 22908, United States
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18
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Ovarian Cycle Stages Modulate Alzheimer-Related Cognitive and Brain Network Alterations in Female Mice. eNeuro 2018; 5:eN-NWR-0132-17. [PMID: 30627643 PMCID: PMC6325547 DOI: 10.1523/eneuro.0132-17.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 10/26/2018] [Accepted: 11/02/2018] [Indexed: 02/02/2023] Open
Abstract
Alzheimer’s disease (AD) begins several decades before the onset of clinical symptoms, at a time when women may still undergo reproductive cycling. Whether ovarian functions alter substrates of AD pathogenesis is unknown. Here we show that ovarian cycle stages significantly modulate AD-related alterations in neural network patterns, cognitive impairments, and pathogenic protein production in the hAPP-J20 mouse model of AD. Female hAPP mice spent more time in estrogen-dominant cycle stages and these ovarian stages worsened AD-related network dysfunction and cognitive impairments. In contrast, progesterone-dominant stages and gonadectomy attenuated these AD-related deficits. Further studies revealed a direct role for estradiol in stimulating neural network excitability and susceptibility to seizures in hAPP mice and increasing amyloid beta levels. Understanding dynamic effects of the ovarian cycle on the female nervous system in disease, including AD, is of critical importance and may differ from effects on a healthy brain. The pattern of ovarian cycle effects on disease-related networks, cognition, and pathogenic protein expression may be relevant to young women at risk for AD.
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19
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Aromatase inhibition by letrozole attenuates kainic acid-induced seizures but not neurotoxicity in mice. Epilepsy Res 2018; 143:60-69. [DOI: 10.1016/j.eplepsyres.2018.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/02/2018] [Accepted: 04/07/2018] [Indexed: 12/11/2022]
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20
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Khodamoradi M, Ghazvini H, Esmaeili-Mahani S, Shahveisi K, Farnia V, Zhaleh H, Abdoli N, Akbarnejad Z, Saadati H, Sheibani V. Genistein attenuates seizure-induced hippocampal brain-derived neurotrophic factor overexpression in ovariectomized rats. J Chem Neuroanat 2018. [DOI: 10.1016/j.jchemneu.2018.03.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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21
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Pham DH, Tan CC, Homan CC, Kolc KL, Corbett MA, McAninch D, Fox AH, Thomas PQ, Kumar R, Gecz J. Protocadherin 19 (PCDH19) interacts with paraspeckle protein NONO to co-regulate gene expression with estrogen receptor alpha (ERα). Hum Mol Genet 2017; 26:2042-2052. [PMID: 28334947 PMCID: PMC5437529 DOI: 10.1093/hmg/ddx094] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 03/08/2017] [Indexed: 11/12/2022] Open
Abstract
De novo and inherited mutations of X-chromosome cell adhesion molecule protocadherin 19 (PCDH19) cause frequent, highly variable epilepsy, autism, cognitive decline and behavioural problems syndrome. Intriguingly, hemizygous null males are not affected while heterozygous females are, contradicting established X-chromosome inheritance. The disease mechanism is not known. Cellular mosaicism is the likely driver. We have identified p54nrb/NONO, a multifunctional nuclear paraspeckle protein with known roles in nuclear hormone receptor gene regulation, as a PCDH19 protein interacting partner. Using breast cancer cells we show that PCDH19-NONO complex is a positive co-regulator of ERα-mediated gene expression. Expression of mutant PCDH19 affects at least a subset of known ERα-regulated genes. These data are consistent with our findings that genes regulated by nuclear hormone receptors and those involved in the metabolism of neurosteroids in particular are dysregulated in PCDH19-epilepsy girls and affected mosaic males. Overall we define and characterize a novel mechanism of gene regulation driven by PCDH19, which is mediated by paraspeckle constituent NONO and is ERα-dependent. This PCDH19-NONO-ERα axis is of relevance not only to PCDH19-epilepsy and its comorbidities but likely also to ERα and generally nuclear hormone receptor-associated cancers.
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Affiliation(s)
- Duyen H. Pham
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
| | - Chuan C. Tan
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
| | - Claire C. Homan
- School of Biological Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Kristy L. Kolc
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
| | - Mark A. Corbett
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
| | - Dale McAninch
- School of Biological Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Archa H. Fox
- School of Human Sciences and School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009 and Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, 6009, Australia
| | - Paul Q. Thomas
- School of Biological Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Raman Kumar
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
| | - Jozef Gecz
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
- School of Biological Sciences, The University of Adelaide, Adelaide 5000, Australia
- South Australian Health and Medical Research Institute, Adelaide 5000, Australia
- To whom correspondence should be addressed. Tel: +61 883133245; Fax: +61 881617342;
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22
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Amiri Gheshlaghi S, Mohammad Jafari R, Algazo M, Rahimi N, Alshaib H, Dehpour AR. Genistein modulation of seizure: involvement of estrogen and serotonin receptors. J Nat Med 2017; 71:537-544. [PMID: 28439683 DOI: 10.1007/s11418-017-1088-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/17/2017] [Indexed: 11/26/2022]
Abstract
Genistein, a major source of phytoestrogen exposure for humans and animals, has been shown to mediate neuroprotection in Alzheimer's disease and status epilepticus. In the present study, we investigated the effect of genistein on pentylenetetrazole-induced seizures in ovariectomized mice and the possible involvement of estrogenic and serotonergic pathways in the probable effects of genistein. Intraperitoneal (i.p.) administration of genistein (10 mg/kg) significantly increased the seizure threshold 30 min prior to induction of seizures 14 days after ovariectomy surgery. Administration of fulvestrant (1 mg/kg, i.p.), an estrogen receptor antagonist, completely reversed the anticonvulsant effect of genistein (10 mg/kg) in ovariectomized mice. Administration of the antagonist of serotonin receptor (5-HT3), tropisetron (10 mg/kg, i.p.), eliminated the anticonvulsant effect of genistein, whereas co-administration of m-chlorophenylbiguanide (5-HT3 receptor agonist; 1 mg/kg) and a non-effective dose of genistein (5 mg/kg) increased the seizure threshold. To conclude, it seems that estrogenic/serotonergic systems might be involved in the anticonvulsant properties of genistein.
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Affiliation(s)
- Saeed Amiri Gheshlaghi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, 13145-784, Iran
| | - Razieh Mohammad Jafari
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, 13145-784, Iran
| | - Mohammad Algazo
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, 13145-784, Iran
| | - Nastaran Rahimi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, 13145-784, Iran
| | - Hussein Alshaib
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, 13145-784, Iran
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, 13145-784, Iran.
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Khodamoradi M, Asadi-Shekaari M, Esmaeili-Mahani S, Esmaeilpour K, Sheibani V. Effects of genistein on cognitive dysfunction and hippocampal synaptic plasticity impairment in an ovariectomized rat kainic acid model of seizure. Eur J Pharmacol 2016; 786:1-9. [DOI: 10.1016/j.ejphar.2016.05.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 04/21/2016] [Accepted: 05/23/2016] [Indexed: 11/24/2022]
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Sato SM, Woolley CS. Acute inhibition of neurosteroid estrogen synthesis suppresses status epilepticus in an animal model. eLife 2016; 5. [PMID: 27083045 PMCID: PMC4862752 DOI: 10.7554/elife.12917] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 04/11/2016] [Indexed: 12/31/2022] Open
Abstract
Status epilepticus (SE) is a common neurological emergency for which new treatments are needed. In vitro studies suggest a novel approach to controlling seizures in SE: acute inhibition of estrogen synthesis in the brain. Here, we show in rats that systemic administration of an aromatase (estrogen synthase) inhibitor after seizure onset strongly suppresses both electrographic and behavioral seizures induced by kainic acid (KA). We found that KA-induced SE stimulates synthesis of estradiol (E2) in the hippocampus, a brain region commonly involved in seizures and where E2 is known to acutely promote neural activity. Hippocampal E2 levels were higher in rats experiencing more severe seizures. Consistent with a seizure-promoting effect of hippocampal estrogen synthesis, intra-hippocampal aromatase inhibition also suppressed seizures. These results reveal neurosteroid estrogen synthesis as a previously unknown factor in the escalation of seizures and suggest that acute administration of aromatase inhibitors may be an effective treatment for SE. DOI:http://dx.doi.org/10.7554/eLife.12917.001 Seizures occur when connected groups of cells in the brain become over-active and fire together. Current anti-seizure medications work by reducing brain activity generally. Although this is often effective in controlling seizures, it can also lead to negative side effects like drowsiness, dizziness or difficulty concentrating. A better alternative would be to target a factor that promotes activity especially during seizures. Most people think of estrogens as being female sex hormones. However, estrogens are also made in the brain of both sexes, where they could promote activity during seizures. Sato and Woolley therefore set out to test a two-part hypothesis: that seizures stimulate the production of estrogen in the brain, and that inhibiting this production process just as seizures begin would make seizures less severe. Sato and Woolley studied male and female rats and found that in both sexes, seizures stimulate the production of estrogens in the hippocampus – a part of the brain that is often involved in seizures. Because estrogens are known to increase the activity of cells in the hippocampus, this suggested that estrogens that are produced in the brain during seizures could make seizures worse. Sato and Woolley tested this by injecting rats with a drug that inhibits estrogen production, called an aromatase inhibitor, shortly after seizures began. The drug strongly suppressed seizures, whereas control rats that did not receive the injection continued to have seizures. Overall, Sato and Woolley show that the production of estrogen in the brain escalates seizure activity, and suggest that aromatase inhibitors may be useful for controlling seizures. Several questions remain that require further study. How does seizure activity lead to estrogen being made in the brain? How do estrogen levels go back down after a seizure? What circumstances other than seizures stimulate brain estrogen production, and what roles does this production process play in activity that is not related to seizures? DOI:http://dx.doi.org/10.7554/eLife.12917.002
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Affiliation(s)
- Satoru M Sato
- Department of Neurobiology, Northwestern University, Evanston, United States
| | - Catherine S Woolley
- Department of Neurobiology, Northwestern University, Evanston, United States
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Quinn TA, Ratnayake U, Dickinson H, Castillo-Melendez M, Walker DW. Ontogenetic Change in the Regional Distribution of Dehydroepiandrosterone-Synthesizing Enzyme and the Glucocorticoid Receptor in the Brain of the Spiny Mouse (Acomys cahirinus). Dev Neurosci 2015; 38:54-73. [PMID: 26501835 DOI: 10.1159/000438986] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/24/2015] [Indexed: 11/19/2022] Open
Abstract
The androgen dehydroepiandrosterone (DHEA) has trophic and anti-glucocorticoid actions on brain growth. The adrenal gland of the spiny mouse (Acomys cahirinus) synthesizes DHEA. The aim of this study was to determine whether the brain of this precocial species is also able to produce DHEA de novo during fetal, neonatal and adult life. The expression of P450c17 and cytochrome b5 (Cytb5), the enzyme and accessory protein responsible for the synthesis of DHEA, was determined in fetal, neonatal and adult brains by immunocytochemistry, and P450c17 bioactivity was determined by the conversion of pregnenolone to DHEA. Homogenates of fetal brain produced significantly more DHEA after 48 h in culture (22.46 ± 2.0 ng/mg tissue) than adult brain homogenates (5.04 ± 2.0 ng/mg tissue; p < 0.0001). P450c17 and Cytb5 were co-expressed in fetal neurons but predominantly in oligodendrocytes and white matter tracts in the adult brain. Because DHEA modulates glucocorticoids actions, the expression of the glucocorticoid receptor (GR) was also determined. In the brainstem, medulla, midbrain, and cerebellum, the predominant GR localization changed from neurons in the fetal brain to oligodendrocytes and white matter tracts in the adult brain. The change of expression of P450c17, Cytb5 and GR proteins with cell type, brain region and developmental age indicates that DHEA is an endogenous neurosteroid in this species that may have important trophic and stress-modifying actions during both prenatal and postnatal life.
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Affiliation(s)
- Tracey A Quinn
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Vic., Australia
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Reduced estradiol synthesis by letrozole, an aromatase inhibitor, is protective against development of pentylenetetrazole-induced kindling in mice. Neurochem Int 2015; 90:271-4. [PMID: 26449311 DOI: 10.1016/j.neuint.2015.10.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 09/29/2015] [Accepted: 10/01/2015] [Indexed: 01/16/2023]
Abstract
Neurosteroids, such as testosterone and their metabolites, are known to modulate neuronal excitability. The enzymes regulating the metabolism of these neurosteroids, thus, may be targeted as a noval strategy for the development of new antiepileptic drugs. The present work targeted two such enzymes i,e aromatase and 5α-reductase in order to explore the potential of letrozole (an aromatase inhibitor) on pentylenetetrazole (PTZ)-induced kindling in mice and the ability of finasteride (a 5α-reductase inhibitor) to modulate any such effects. PTZ (30 mg/kg, i.p.), when administered once every two days (for a total of 24 doses) induced kindling in Swiss albino mice. Letrozole (1 mg/kg, p.o.), administered prior to PTZ, significantly reduced the % incidence of kindling, delayed mean onset time of seizures and reduced seizure severity score. Letrozole reduced the levels of plasma 17β-estradiol after induction of kindling. The concurrent administration of finasteride and letrozole produced effects similar to letrozole on PTZ-kindling and on estradiol levels. This implies that the ability of letrozole to redirect the synthesis of dihydrotestosterone (DHT) and 5α-androstanediol from testosterone doesn't appear to play a significant role in the protective effects of letrozole against PTZ kindling. Letrozole, however, increased the levels of 5α-DHT in mice plasma. The aromatase inhibitors, thus, may be exploited for inhibiting the synthesis of proconvulsant (17β-estradiol) and/or redirecting the synthesis of anticonvulsant (DHT and 5α-androstanediol) neurosteroids.
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Pottoo F, Bhowmik M, Vohora D. Raloxifene protects against seizures and neurodegeneration in a mouse model mimicking epilepsy in postmenopausal woman. Eur J Pharm Sci 2014; 65:167-73. [DOI: 10.1016/j.ejps.2014.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/19/2014] [Accepted: 09/03/2014] [Indexed: 11/28/2022]
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Zendehdel M, Kaboutari J, Ghadimi D, Hassanpour S. The Antiepileptic Effect of Ghrelin During Different Phases of the Estrous Cycle in PTZ-Induced Seizures in Rat. Int J Pept Res Ther 2014. [DOI: 10.1007/s10989-014-9418-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Alam MN, Ahmad A, Al-Abbasi FA, Ahmad A. Female ovarian steroids in epilepsy: a cause or remedy. Pharmacol Rep 2014; 65:802-12. [PMID: 24145074 DOI: 10.1016/s1734-1140(13)71061-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Revised: 02/16/2013] [Indexed: 10/25/2022]
Abstract
In this article, we review published preclinical and clinical studies that examine the role of female ovarian steroids (estrogen and progesterone) in epilepsy. Its effects on the reproductive and endocrine system are well known but a large and growing body of evidences indicates that the hormones also exert neuroprotective effects on the central nervous system. Estrogen crosses the blood-brain barrier due to its low molecular weight and lipophilic properties and easily reaches the neuronal tissue. Estrogens and progesterone influence neuronal activity and are important for normal brain functions. It is commonly accepted that estrogens may increase neuronal excitability and thus mediate proconvulsant effects whereas in case of progesterone, various preclinical and clinical studies have proved that progesterone shows anticonvulsant effects. To concise our review we concluded that the effects of estrogens and progesterone on seizures depend on various factors, such as treatment duration and latency prior to the seizure testing, dose, hormonal status, the seizure type/model used and sex.
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Affiliation(s)
- Mohammad N Alam
- Department of Pharmaceutics, College of Pharmacy, King Khalid University, Abha, Postal Code-61466, Kingdom of Saudi Arabia.
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Ahmad A, Vohora D. Proconvulsant effects of estriol, the third estrogen, in the mouse PTZ-kindling model. Neurol Sci 2014; 35:1561-6. [DOI: 10.1007/s10072-014-1795-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 04/05/2014] [Indexed: 11/28/2022]
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Effect of prenatal methamphetamine exposure and challenge dose of the same drug in adulthood on epileptiform activity induced by electrical stimulation in female rats. Neuroscience 2014; 257:130-8. [DOI: 10.1016/j.neuroscience.2013.10.069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 10/14/2013] [Accepted: 10/28/2013] [Indexed: 12/28/2022]
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Badawy RAB, Vogrin SJ, Lai A, Cook MJ. Are patterns of cortical hyperexcitability altered in catamenial epilepsy? Ann Neurol 2013; 74:743-57. [PMID: 23686575 DOI: 10.1002/ana.23923] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 04/13/2013] [Accepted: 04/26/2013] [Indexed: 11/05/2022]
Abstract
OBJECTIVE We used transcranial magnetic stimulation to determine menstrual cycle-related changes in cortical excitability in women with and without catamenial epilepsy and investigated whether these changes differed between ovulatory and anovulatory cohorts. METHODS Healthy nonepilepsy women and women with generalized and focal epilepsy were investigated during ovulatory (n=11, 46, and 43, respectively) and anovulatory (n=9, 42, and 41) cycles. Patients were divided based on seizure pattern into catamenial (C1=perimenstrual, C2=periovulatory, C3=luteal seizure exacerbation), noncatamenial, and seizure free. Cortical excitability was assessed using motor threshold (MT) and paired pulse stimulation at short (2-15 milliseconds) and long (100-300 milliseconds) interstimulus intervals twice, at the (1) late follicular and (2) mid luteal phases of the menstrual cycle. RESULTS In controls, cortical excitability was greatest in the follicular study, where intracortical facilitation was increased (p<0.05). The opposite was seen in women with epilepsy, where intracortical facilitation was greatest and intracortical inhibition was least in the luteal studies (p<0.05). There were no differences between the ovulatory and anovulatory groups in any of the cohorts. No changes were observed in MT. INTERPRETATION Nonhormonal factors are involved in the cyclicity of cortical excitability across the menstrual cycle. Normal menstrual cycle variations in cortical excitability are altered in a similar pattern in ovulatory and anovulatory women with epilepsy regardless of seizure patterns. The underlying neural changes associated with epilepsy may alter responses to sex hormones. This may be an important underlying mechanism for catamenial seizure clustering.
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Affiliation(s)
- Radwa A B Badawy
- Department of Clinical Neurosciences, St Vincent's Hospital, Fitzroy, Australia; Department of Medicine, University of Melbourne, Parkville, Australia; Electrical and Electronic Engineering, University of Melbourne, Parkville, Australia
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Velíšková J, Velíšek L. Gonadal status-dependent effects of in vivo β-estradiol administration to female rats on in vitro epileptiform activity induced by low [Mg2+]₀ in combined hippocampus-entorhinal cortex slices. Epilepsy Res 2013; 107:297-301. [PMID: 24113171 DOI: 10.1016/j.eplepsyres.2013.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 09/09/2013] [Accepted: 09/12/2013] [Indexed: 11/19/2022]
Abstract
There are controversial data regarding estrogen effects on neuronal excitability. We investigated whether β-estradiol (EB) administration to ovariectomized (OVX) or gonadally intact female rats alters epileptiform activity within the dentate gyrus network induced in vitro by removing [Mg2+]o in combined hippocampus-entorhinal cortex slices. In vivo EB administration significantly influenced the epileptiform activity in gonadal status-dependent manner. The onset of epileptiform discharges was modestly delayed in slices from OVX rats replaced with physiologically relevant doses of EB but the number of discharges was not affected. In contrast, EB administration to gonadally intact rats had robust effects such that: EB delayed the onset of discharges but significantly increased their number within the dentate gyrus network. Our data suggest that EB in physiologically relevant concentrations does not seem to negatively affect hippocampal neuronal excitability, nevertheless supraphysiological EB levels may enhance seizure severity.
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Affiliation(s)
- Jana Velíšková
- Departments of Cell Biology & Anatomy, New York Medical College, Valhalla, NY, USA; Departments of Obstetrics & Gynecology, New York Medical College, Valhalla, NY, USA; Departments of Neurology, New York Medical College, Valhalla, NY, USA.
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Reddy DS. Role of hormones and neurosteroids in epileptogenesis. Front Cell Neurosci 2013; 7:115. [PMID: 23914154 PMCID: PMC3728472 DOI: 10.3389/fncel.2013.00115] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 07/01/2013] [Indexed: 12/03/2022] Open
Abstract
This article describes the emerging evidence of hormonal influence on epileptogenesis, which is a process whereby a brain becomes progressively epileptic due to an initial precipitating event of diverse origin such as brain injury, stroke, infection, or prolonged seizures. The molecular mechanisms underlying the development of epilepsy are poorly understood. Neuroinflammation and neurodegeneration appear to trigger epileptogenesis. There is an intense search for drugs that truly prevent the development of epilepsy in people at risk. Hormones play an important role in children and adults with epilepsy. Corticosteroids, progesterone, estrogens, and neurosteroids have been shown to affect seizure activity in animal models and in clinical studies. However, the impact of hormones on epileptogenesis has not been investigated widely. There is emerging new evidence that progesterone, neurosteroids, and endogenous hormones may play a role in regulating the epileptogenesis. Corticosterone has excitatory effects and triggers epileptogenesis in animal models. Progesterone has disease-modifying activity in epileptogenic models. The antiepileptogenic effect of progesterone has been attributed to its conversion to neurosteroids, which binds to GABA-A receptors and enhances phasic and tonic inhibition in the brain. Neurosteroids are robust anticonvulsants. There is pilot evidence that neurosteroids may have antiepileptogenic properties. Future studies may generate new insight on the disease-modifying potential of hormonal agents and neurosteroids in epileptogenesis.
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Affiliation(s)
- Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center Bryan, TX, USA
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35
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Velíšková J, Desantis KA. Sex and hormonal influences on seizures and epilepsy. Horm Behav 2013; 63:267-77. [PMID: 22504305 PMCID: PMC3424285 DOI: 10.1016/j.yhbeh.2012.03.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/28/2012] [Accepted: 03/29/2012] [Indexed: 11/20/2022]
Abstract
Epilepsy is the third most common chronic neurological disorder. Clinical and experimental evidence supports the role of sex and influence of sex hormones on seizures and epilepsy as well as alterations of the endocrine system and levels of sex hormones by epileptiform activity. Conversely, seizures are sensitive to changes in sex hormone levels, which in turn may affect the seizure-induced neuronal damage. The effects of reproductive hormones on neuronal excitability and seizure-induced damage are complex to contradictory and depend on different mechanisms, which have to be accounted for in data interpretation. Both estradiol and progesterone/allopregnanolone may have beneficial effects for patients with epilepsy. Individualized hormonal therapy should be considered as adjunctive treatment in patients with epilepsy to improve seizure control as well as quality of life.
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Affiliation(s)
- Jana Velíšková
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY, USA.
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Kaboutari J, Zendehdel M, Habibian S, Azimi M, Shaker M, Karimi B. The antiepileptic effect of sodium valproate during different phases of the estrous cycle in PTZ-induced seizures in rats. J Physiol Biochem 2011; 68:155-61. [PMID: 22076911 DOI: 10.1007/s13105-011-0127-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 10/26/2011] [Indexed: 01/24/2023]
Abstract
Catamenial epilepsy is a form of epilepsy which is related to the menstrual cycle. Cyclic variation in the levels of ovarian hormones plays a pivotal role in its pathogenesis. Sodium valproate (VPA) is one of the oldest antiepileptic drugs (AEDs) which inhibits hepatic metabolizing enzymes. The aim of this study was to evaluate the antiepileptic effects of VPA during different phases of the estrous cycle in rats. 72 adult female Wistar rats in three groups (control, 75 and 100 mg/kg VPA), each with four subgroups (proestrous, estrous, metestrous and diestrous) were used (n = 6). Initially, puberty was assessed using vaginal smears and rats with two regular cycles were selected. VPA with doses 75 and 100 mg/kg was administered intraperitoneally (i.p) in the treatment groups followed by i.p. injection of 80 mg/kg pentylentetrazol (PTZ) in the treatment and control groups. After induction of seizure by PTZ, initiation time of myoclonic seizures (ITMS), initiation time of tonic-clonic seizures (ITTS), seizures duration (SD) and mortality rate (MR) were recorded for 30 min. Data were presented as mean±SD, one-way ANOVA followed by Tukey-Kramer multiple comparison post hoc test were used for analysis of data (P < 0.05). The results of this study showed that VPA significantly improved antiepileptic parameters including ITMS, ITTS, SD, and MR, in which they were significantly more prominent during the luteal phase than the follicular phase (P < 0.05). In addition, there was no significant difference neither between proestrous and estrous nor between metestrous and diestrous in each separately group of rats (P > 0.05).
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Affiliation(s)
- Jahangir Kaboutari
- Department of Basic Sciences, University of Shahrekord, 8818634141115, Shahrekord, Iran.
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38
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Öztürk B, Yeni SN, Karaağaç N, Özkara Ç. No effects of the gonadal hormones on photoparoxysmal EEG responses in idiopathic generalised epilepsy. Seizure 2011; 20:598-601. [DOI: 10.1016/j.seizure.2011.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 03/04/2011] [Accepted: 04/22/2011] [Indexed: 11/28/2022] Open
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Abstract
PURPOSE OF REVIEW Epilepsy and anticonvulsant medications may substantially alter endocrine homeostasis, including the male reproductive hormonal system. RECENT FINDINGS Seizures in medial temporal lobe structures, through their connectivity to the hypothalamus, alter the secretion of gonadotropins. Levels of circulating bioavailable testosterone are affected by changes in the level of binding proteins, which in turn may be affected by seizure medications. The use of older generation medications that induce the cytochrome P450 system is associated with an increase in sex hormone-binding globulin and lower bioactive testosterone. Sexual dysfunction, including decreased libido and decreased potency, and infertility, is seen commonly in men with epilepsy. However, its relation to sex hormone levels remains unclear. Comorbid depression and anxiety may be important confounding factors. Testosterone and sexual function appear not to be affected by the newer generation (noninducing) anticonvulsants. SUMMARY Epilepsy and its drug treatments are associated with alterations in hormonal and sexual function in men. Further study is needed to clarify the precise mechanisms behind these alterations, as some of the data conflict. More attention should be paid to this issue in male patients with seizures; when appropriate, treatment for psychiatric comorbidity and switches in anticonvulsant therapy may be worth consideration.
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Affiliation(s)
- Kartik Sivaraaman
- Jefferson Comprehensive Epilepsy Center, Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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Slamberová R, Hrubá L, Matějovská I, Bernášková K, Rokyta R. Increased seizure susceptibility induced by prenatal methamphetamine exposure in adult female rats is not affected by early postnatal cross-fostering. Epilepsy Behav 2011; 20:6-11. [PMID: 21067979 DOI: 10.1016/j.yebeh.2010.10.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 10/06/2010] [Accepted: 10/06/2010] [Indexed: 10/18/2022]
Abstract
Our previous studies repeatedly demonstrated that prenatal methamphetamine (MA) exposure alters seizure susceptibility in adult rats. Both the inhibitory GABA system and the excitatory NMDA system play a role in the effect of MA on epileptic seizures. On the basis of our previous behavioral results, the effect of cross-fostering on seizure susceptibility in adult female rats was examined in the present study. Bicuculline (GABA(A) receptor antagonist) and NMDA (NMDA receptor agonist) were used to induce seizures in adult female offspring exposed to MA in the prenatal and/or preweaning periods. Female dams were injected with MA (5mg/kg daily) or physiological saline (S) for approximately 9 weeks [about 3 weeks prior to impregnation, for the entire gestation period (22 days), and in the preweaning period (21 days)]. Absolute controls (C) did not receive any injections. On postnatal day 1, pups were cross-fostered so that each mother received pups from all three treatments. Thus, nine groups (based on the prenatal and postnatal drug exposures) of adult female rats were tested in each seizure test: C/C, C/S, C/MA, S/C, S/S, S/MA, MA/C, MA/S, MA/MA. The present study demonstrated that both the excitatory NMDA system and the inhibitory GABA system are involved in the proconvulsive effect of MA during prenatal and partially also postnatal development in female rats. However, because our results did not show any improvement in seizure susceptibility in prenatally MA-exposed animals that were fostered by control mothers (MA/C) relative to their siblings fostered by MA-treated mothers (MA/MA), our hypothesis of the cross-fostering effect seems to be incorrect in contrast to our behavioral studies.
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Affiliation(s)
- R Slamberová
- Department of Normal, Pathological, and Clinical Physiology, Prague, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
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Biasi E. Effects of postnatal dietary choline manipulation against MK-801 neurotoxicity in pre- and postadolescent rats. Brain Res 2010; 1362:117-32. [PMID: 20846509 DOI: 10.1016/j.brainres.2010.09.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 09/03/2010] [Accepted: 09/03/2010] [Indexed: 12/29/2022]
Abstract
Prenatal supplementation of rat dams with dietary choline has been shown to provide their offspring with neuroprotection against N-methyl-d-aspartate (NMDA) antagonist-mediated neurotoxicity. This study investigated whether postnatal dietary choline supplementation exposure for 30 and 60 days of rats starting in a pre-puberty age would also induce neuroprotection (without prenatal exposure). Male and female Sprague-Dawley rats (postnatal day 30 of age) were reared for 30 or 60 concurrent days on one of the four dietary levels of choline: 1) fully deficient choline, 2) 1/3 the normal level, 3) the normal level, or 4) seven times the normal level. After diet treatment, the rats received one injection of MK-801 (dizocilpine 3mg/kg) or saline control. Seventy-two hours later, the rats were anesthetized and transcardially perfused. Their brains were then postfixed for histology with Fluorojade-C (FJ-C) staining. Serial coronal sections were prepared from a rostrocaudal direction from 1.80 to 4.2mm posterior to the bregma to examine cell degeneration in the retrosplenial and piriform regions. MK-801, but not control saline, produced significant numbers of FJ-C positive neurons, indicating considerable neuronal degeneration. Dietary choline supplementation or deprivation in young animals reared for 30-60days did not alter NMDA antagonist-induced neurodegeneration in the retrosplenial region. An interesting finding is the absence of the piriform cortex involvement in young male rats and the complete absence of neurotoxicity in both hippocampus regions and DG. However, neurotoxicity in the piriform cortex of immature females treated for 60days appeared to be suppressed by low levels of dietary choline.
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Affiliation(s)
- Elisabetta Biasi
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
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Slamberová R, Schutová B, Bernásková K, Matejovská I, Rokyta R. Challenge dose of methamphetamine affects kainic acid-induced seizures differently depending on prenatal methamphetamine exposure, sex, and estrous cycle. Epilepsy Behav 2010; 19:26-31. [PMID: 20708438 DOI: 10.1016/j.yebeh.2010.06.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 06/21/2010] [Accepted: 06/21/2010] [Indexed: 10/19/2022]
Abstract
Even though it is obvious that glutamate plays an important role in the effect of psychostimulants on seizures, the role of non-NMDA receptors remains uncertain. The aim of the present study was to determine whether acute methamphetamine (MA) administration changes sensitivity to seizures induced with kainic acid in prenatally MA-exposed adult rats. Adult male and female rats (prenatally MA exposed, prenatally saline exposed, and controls) were divided into groups that received a challenge dose (1mg/kg) of MA and groups that did not receive the MA challenge (saline injected). Systemic administration of 15 mg/kg kainic acid was used as a seizure model. Our results demonstrated that a single injection of MA (1mg/kg) affects kainic acid-induced seizures differently depending on prenatal exposure, sex, and female estrous cycle. Even though daily injections of MA (5mg/kg) in maternal rats did not have a long-term effect on susceptibility to seizures induced with kainic acid in adult progeny, sensitivity to the challenge dose of MA differed between the prenatal exposure groups.
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Affiliation(s)
- Romana Slamberová
- Department of Normal, Pathological and Clinical Physiology, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
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Reddy DS. The role of neurosteroids in the pathophysiology and treatment of catamenial epilepsy. Epilepsy Res 2009; 85:1-30. [PMID: 19406620 PMCID: PMC2696558 DOI: 10.1016/j.eplepsyres.2009.02.017] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 02/23/2009] [Accepted: 02/25/2009] [Indexed: 01/14/2023]
Abstract
Catamenial epilepsy is a multifaceted neuroendocrine condition in which seizures are clustered around specific points in the menstrual cycle, most often around perimenstrual or periovulatory period. Generally, a twofold or greater increase in seizure frequency during a particular phase of the menstrual cycle could be considered as catamenial epilepsy. Based on this criteria, recent clinical studies indicate that catamenial epilepsy affects 31-60% of the women with epilepsy. Three types of catamenial seizures (perimenstrual, periovulatory and inadequate luteal) have been identified. However, there is no specific drug available today for catamenial epilepsy, which has not been successfully treated with conventional antiepileptic drugs. Elucidation of the pathophysiology of catamenial epilepsy is a prerequisite to develop specific targeted approaches for treatment or prevention of the disorder. Cyclical changes in the circulating levels of estrogens and progesterone play a central role in the development of catamenial epilepsy. There is emerging evidence that endogenous neurosteroids with anticonvulsant or proconvulsant effects could play a critical role in catamenial epilepsy. It is thought that perimenstrual catamenial epilepsy is associated with the withdrawal of anticonvulsant neurosteroids. Progesterone and other hormonal agents have been shown in limited trials to be moderately effective in catamenial epilepsy, but may cause endocrine side effects. Synthetic neurosteroids, which enhance the tonic GABA-A receptor function, might provide an effective approach for the catamenial epilepsy therapy without producing hormonal side effects.
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Affiliation(s)
- Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, 228 Reynolds Medical Building, College Station, TX 77843-1114, USA.
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Estradiol facilitates the release of neuropeptide Y to suppress hippocampus-dependent seizures. J Neurosci 2009; 29:1457-68. [PMID: 19193892 DOI: 10.1523/jneurosci.4688-08.2009] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
About one-third of women with epilepsy have a catamenial seizure pattern, in which seizures fluctuate with the menstrual cycle. Catamenial seizures occur more frequently when the ratio of circulating estradiol to progesterone is high, suggesting that estradiol is proconvulsant. We used adult female rats to test how estradiol-induced suppression of GABAergic inhibition in the hippocampus affects behavioral seizures induced by kainic acid. As expected, estradiol decreased the latency to initiate seizures, indicating increased seizure susceptibility. At the same time, however, estradiol also shortened the duration of late-stage seizures, indicating decreased seizure severity. Additional analyses showed that the decrease in seizure severity was attributable to greater release of the anticonvulsant neuropeptide, neuropeptide Y (NPY). First, blocking hippocampal NPY during seizures eliminated the estradiol-induced decrease in seizure duration. Second, light and electron microscopic studies indicated that estradiol increases the potentially releasable pool of NPY in inhibitory presynaptic boutons and facilitates the release of NPY from inhibitory boutons during seizures. Finally, the presence of estrogen receptor-alpha on large dense-core vesicles (LDCVs) in the hippocampus suggests that estradiol could facilitate neuropeptide release by acting directly on LDCVs themselves. Understanding how estradiol regulates NPY-containing LDCVs could point to molecular targets for novel anticonvulsant therapies.
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Torres-Reveron A, Khalid S, Williams TJ, Waters EM, Jacome L, Luine VN, Drake CT, McEwen BS, Milner TA. Hippocampal dynorphin immunoreactivity increases in response to gonadal steroids and is positioned for direct modulation by ovarian steroid receptors. Neuroscience 2008; 159:204-16. [PMID: 19150393 DOI: 10.1016/j.neuroscience.2008.12.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 12/09/2008] [Accepted: 12/16/2008] [Indexed: 11/17/2022]
Abstract
The hippocampal formation (HF) is involved in modulating learning related to drug abuse. While HF-dependent learning is regulated by both endogenous opioids and estrogen, the interaction between these two systems is not well understood. The mossy fiber (MF) pathway formed by dentate gyrus (DG) granule cell axons is involved in some aspects of learning and contains abundant amounts of the endogenous opioid peptide dynorphin (DYN). To examine the influence of ovarian steroids on DYN expression, we used quantitative light microscopic immunocytochemistry to measure DYN levels in normal cycling rats as well as in two established models of hormone-treated ovariectomized (OVX) rats. Rats in estrus had increased levels of DYN-immunoreactivity (ir) in the DG and certain CA3 lamina compared with rats in proestrus or diestrus. OVX rats exposed to estradiol for 24 h showed increased DYN-ir in the DG and CA3, while those with 72 h estradiol exposure showed increases only in the DG. Six hours of estradiol exposure produced no change in DYN-ir. OVX rats chronically implanted with medroxyprogesterone also showed increased DYN-ir in the DG and CA3. Next, dual-labeling electron microscopy (EM) was used to evaluate the subcellular relationships of estrogen receptor (ER) alpha-, ERbeta and progestin receptor (PR) with DYN-labeled MFs. ERbeta-ir was in some DYN-labeled MF terminals and smaller terminals, and had a subcellular association with the plasmalemma and small synaptic vesicles. In contrast, ERalpha-ir was not in DYN-labeled terminals, although some DYN-labeled small terminals synapsed on ERalpha-labeled dendritic spines. PR labeling was mostly in CA3 axons, some of which were continuous with DYN-labeled terminals. These studies indicate that ovarian hormones can modulate DYN in the MF pathway in a time-dependent manner, and suggest that hormonal effects on the DYN-containing MF pathway may be directly mediated by ERbeta and/or PR activation.
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Affiliation(s)
- A Torres-Reveron
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, 411 East 69th Street, New York, NY 10021, USA
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Aladdin Y, Gross DW. Refractory status epilepticus during pregnancy secondary to cavernous angioma. Epilepsia 2008; 49:1627-9. [DOI: 10.1111/j.1528-1167.2008.01639.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ovarian steroids modulate leu-enkephalin levels and target leu-enkephalinergic profiles in the female hippocampal mossy fiber pathway. Brain Res 2008; 1232:70-84. [PMID: 18691558 DOI: 10.1016/j.brainres.2008.07.058] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 07/11/2008] [Accepted: 07/15/2008] [Indexed: 02/05/2023]
Abstract
In the hippocampal formation (HF), the enkephalin opioids and estrogen are each known to modulate learning and cognitive performance relevant to drug abuse. Within the HF, leu-enkephalin (LENK) is most prominent in the mossy fiber (MF) pathway formed by the axons of dentate gyrus (DG) granule cells. To examine the influence of ovarian steroids on MF pathway LENK levels, we used quantitative light microscopic immunocytochemistry to evaluate LENK levels in normal cycling rats and in estrogen-treated ovariectomized rats. Rats in estrus had increased levels of LENK-immunoreactivity (ir) in the DG hilus compared to rats in diestrus or proestrus. Rats in estrus and proestrus had higher levels of LENK-ir in CA3a-c compared to rats in diestrus. Ovariectomized (OVX) rats 24 h (but not 6 or 72 h) after estradiol benzoate (EB; 10 microg) administration had increased LENK-ir in the DG hilus and CA3c. Electron microscopy showed a larger proportion of LENK-labeled small terminals and axons in the DG hilus compared to CA3 which may have contributed to region-specific changes in LENK-ir densities. Next we evaluated the subcellular relationships of estrogen receptor (ER) alpha, ERbeta and progestin receptor (PR) with LENK-labeled MF pathway profiles using dual-labeling electron microscopy. ERbeta-ir colocalized in some LENK-labeled MF terminals and smaller terminals while PR-ir was mostly in CA3 axons, some of which also showed colocalization with LENK. ERalpha-ir was in dendritic spines, but no colocalization with LENK-labeled profiles was observed. The present studies indicate that estrogen can modulate LENK in subregions of the MF pathway in a dose-and time-dependent manner. These effects might be triggered by direct activation of ERbeta or PR in LENK-containing terminals.
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de Olmos S, Bueno A, Bender C, Lorenzo A, de Olmos J. Sex differences and influence of gonadal hormones on MK801-induced neuronal degeneration in the granular retrosplenial cortex of the rat. Brain Struct Funct 2008; 213:229-38. [DOI: 10.1007/s00429-008-0186-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2007] [Accepted: 05/16/2008] [Indexed: 10/22/2022]
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Schubert M, Drephal C, Albrecht D. Gender‐dependent ATPA‐induced changes in long‐term potentiation in the rat lateral amygdala. FASEB J 2007; 22:1268-74. [DOI: 10.1096/fj.07-9415com] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Manja Schubert
- Department of PhysiologyFaculty of Medical and Health ScienceUniversity of AucklandAucklandNew Zealand
| | - Christian Drephal
- Institute of NeurophysiologyCharité—Universitätsmedizin BerlinBerlinGermany
- Ev. Krankenhaus BielefeldMedizinische KlinikBielefeldGermany
| | - Doris Albrecht
- Institute of NeurophysiologyCharité—Universitätsmedizin BerlinBerlinGermany
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