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Yao M, Rosario ER, Soper JC, Pike CJ. Androgens Regulate Tau Phosphorylation Through Phosphatidylinositol 3-Kinase-Protein Kinase B-Glycogen Synthase Kinase 3β Signaling. Neuroscience 2022:S0306-4522(22)00335-9. [PMID: 35777535 PMCID: PMC9797620 DOI: 10.1016/j.neuroscience.2022.06.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/11/2022] [Accepted: 06/23/2022] [Indexed: 12/31/2022]
Abstract
Age-related testosterone depletion in men is a risk factor for Alzheimer's disease (AD). How testosterone modulates AD risk remains to be fully elucidated, although regulation of tau phosphorylation has been suggested as a contributing protective action. To investigate the relationship between testosterone and tau phosphorylation, we first evaluated the effect of androgen status on tau phosphorylation in 3xTg-AD mice. Depletion of endogenous androgens via gonadectomy resulted in increased tau phosphorylation that was prevented by acute testosterone treatment. Parallel alterations in the phosphorylation of both glycogen synthase kinase 3β (GSK3β) and protein kinase B (Akt) suggest possible components of the underlying signaling pathway. To further explore mechanism, primary cultured neurons were treated with a physiological concentration of testosterone or its active metabolite dihydrotestosterone (DHT). Results showed that testosterone and DHT induced significant decreases in phosphorylated tau and significant increases in phosphorylation of Akt and GSK3β. Pharmacological inhibition of phosphatidylinositol 3-kinase (PI3K) effectively inhibited androgen-induced increases in Akt and GSK3β phosphorylation, and decreases in tau phosphorylation. In addition, androgen receptor (AR) knock-down by small interfering RNA prevented androgen-induced changes in the phosphorylation of Akt, GSK3β and tau, suggesting an AR-dependent mechanism. Additional experiments demonstrated androgen-induced changes in Akt, GSK3β and tau phosphorylation in AR-expressing PC12 cells but not in AR-negative PC12 cells. Together, these results suggest an AR-dependent pathway involving PI3K-Akt-GSK3β signaling through which androgens can reduce tau phosphorylation. These findings identify an additional protective mechanism of androgens that can improve neural health and inhibit development of AD.
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Affiliation(s)
- Mingzhong Yao
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Emily R Rosario
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Jenna Carroll Soper
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Christian J Pike
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.
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2
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Buggio L, Barbara G, Facchin F, Ghezzi L, Dridi D, Vercellini P. The influence of hormonal contraception on depression and female sexuality: a narrative review of the literature. Gynecol Endocrinol 2022; 38:193-201. [PMID: 34913798 DOI: 10.1080/09513590.2021.2016693] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Over the past decades, an increasing number of women have been using hormonal contraception. The potential role of sex hormones in regulating vegetative, psychophysiological, and cognitive functions has been highlighted in several studies, and there is a need to further understand the impact of hormonal contraception on women's quality of life, especially as regards psychological health and sexuality. METHODS We conducted a narrative review aimed at clarifying the mechanisms involved in the interaction between sex hormones and the brain, also focusing on the association between hormonal contraception and mood and sexual function. RESULTS Our findings clarified that hormonal contraception may be associated with depressive symptoms, especially among adolescents, and with sexual dysfunction. However, the evidence included in this review was conflicting and did not support the hypothesis that hormonal contraception directly causes depressive symptoms, major depressive disorder, or sexual dysfunction. CONCLUSIONS The optimal hormonal contraception should be identified in the context of shared decision making, considering the preferences and needs of each woman, as well as her physical and psychosexual conditions.
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Affiliation(s)
- Laura Buggio
- Gynecology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Giussy Barbara
- Gynecology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- SVSeD, Service for Sexual and Domestic Violence and Obstetric and Gynecology Emergency Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda, Italy
- Department of Clinical Sciences and Community Health, Università Degli Studi di Milano, Milan, Italy
| | - Federica Facchin
- Department of Psychology, Catholic University of the Sacred Heart, Milan, Italy
| | - Laura Ghezzi
- Department of Neurology, Washington University, St. Louis, MO, USA
- Dino Ferrari Center, Università degli Studi di Milano, Milan, Italy
| | - Dhouha Dridi
- Gynecology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Paolo Vercellini
- Gynecology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, Università Degli Studi di Milano, Milan, Italy
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3
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Nakai Y, Nishibayashi H, Donishi T, Terada M, Nakao N, Kaneoke Y. Regional abnormality of functional connectivity is associated with clinical manifestations in individuals with intractable focal epilepsy. Sci Rep 2021; 11:1545. [PMID: 33452388 PMCID: PMC7810833 DOI: 10.1038/s41598-021-81207-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 01/04/2021] [Indexed: 01/29/2023] Open
Abstract
We explored regional functional connectivity alterations in intractable focal epilepsy brains using resting-state functional MRI. Distributions of the network parameters (corresponding to degree and eigenvector centrality) measured at each brain region for all 25 patients were significantly different from age- and sex-matched control data that were estimated by a healthy control dataset (n = 582, 18-84 years old). The number of abnormal regions whose parameters exceeded the mean + 2 SD of age- and sex-matched data for each patient were associated with various clinical parameters such as the duration of illness and seizure severity. Furthermore, abnormal regions for each patient tended to have functional connections with each other (mean ± SD = 58.6 ± 20.2%), the magnitude of which was negatively related to the quality of life. The abnormal regions distributed within the default mode network with significantly higher probability (p < 0.05) in 7 of 25 patients. We consider that the detection of abnormal regions by functional connectivity analysis using a large number of control datasets is useful for the numerical assessment of each patient's clinical conditions, although further study is necessary to elucidate etiology-specific abnormalities.
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Affiliation(s)
- Yasuo Nakai
- Department of Neurological Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan.
| | - Hiroki Nishibayashi
- Department of Neurological Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan
| | - Tomohiro Donishi
- Department of System Neurophysiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan
| | - Masaki Terada
- Wakayama-Minami Radiology Clinic, 870-2 Kimiidera, Wakayama, 641-0012, Japan
| | - Naoyuki Nakao
- Department of Neurological Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan
| | - Yoshiki Kaneoke
- Department of System Neurophysiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan
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4
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Forsgård JA, Metsähonkala L, Kiviranta AM, Cizinauskas S, Junnila JJT, Laitinen-Vapaavuori O, Jokinen TS. Seizure-precipitating factors in dogs with idiopathic epilepsy. J Vet Intern Med 2018; 33:701-707. [PMID: 30576009 PMCID: PMC6430923 DOI: 10.1111/jvim.15402] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 11/21/2018] [Indexed: 02/03/2023] Open
Abstract
Background Stress, sleep deprivation, and infectious diseases are important seizure‐precipitating factors in human epilepsy patients. However, these factors have not been thoroughly studied in epileptic dogs. Objective Seizure‐precipitating factors are common in dogs with idiopathic epilepsy and the occurrence of these factors associate with the dogs' signalment, personality, and epilepsy‐related factors. Animals Fifty dogs with diagnosed idiopathic epilepsy from the hospital populations of University Veterinary Teaching Hospital of University of Helsinki and Referral Animal Hospital Aisti. Methods In a retrospective cross‐sectional observational study, owners were interviewed about their dogs' possible seizure‐precipitating factors according to a predefined questionnaire. The dogs were identified and selected by searching the medical records of the participating animal hospitals. Results The prevalence of seizure‐precipitating factors in the study population was 74% (37/50). The most frequently reported factors included stress‐related situations, sleep deprivation, weather, and hormonal factors. In dogs with focal onset seizures, the number of precipitating factors was 1.9 (95% CI 1.1‐3.4) times higher compared to dogs with generalized seizures. Conclusions and Clinical Importance Seizure‐precipitating factors are common in dogs with idiopathic epilepsy, and the nature of these factors is consistent with those of human patients. Aside from antiepileptic medication, acknowledging and avoiding seizure‐precipitating factors could help veterinarians achieve better treatment outcomes.
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Affiliation(s)
- Johanna A Forsgård
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Liisa Metsähonkala
- Pediatric Neurologist, Hospital of Children and Adolescents, Helsinki University Central Hospital, Helsinki, Finland
| | - Anna-Mariam Kiviranta
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | | | | | - Outi Laitinen-Vapaavuori
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Tarja S Jokinen
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
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5
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Yang W, Westbroek EM, Anderson-Keightly H, Caplan JM, Rong X, Hung AL, Braileanu M, Wang JY, Colby GP, Coon AL, Tamargo RJ, Ahn ES, Huang J. Male Gender Associated with Post-Treatment Seizure Risk of Pediatric Arteriovenous Malformation Patients. Neurosurgery 2017; 80:899-907. [DOI: 10.1093/neuros/nyx018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/10/2017] [Indexed: 11/13/2022] Open
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Siddiqui AN, Siddiqui N, Khan RA, Kalam A, Jabir NR, Kamal MA, Firoz CK, Tabrez S. Neuroprotective Role of Steroidal Sex Hormones: An Overview. CNS Neurosci Ther 2016; 22:342-50. [PMID: 27012165 DOI: 10.1111/cns.12538] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 02/21/2016] [Accepted: 02/21/2016] [Indexed: 12/11/2022] Open
Abstract
Progesterone, estrogens, and testosterone are the well-known steroidal sex hormones, which have been reported to have "nonreproductive "effects in the brain, specifically in the neuroprotection and neurotrophy. In the last one decade, there has been a surge in the research on the role of these hormones in neuroprotection and their positive impact on different brain injuries. The said interest has been sparked by a desire to understand the action and mechanisms of these steroidal sex hormones throughout the body. The aim of this article was to highlight the potential outcome of the steroidal hormones, viz. progesterone, estrogens, and testosterone in terms of their role in neuroprotection and other brain injuries. Their possible mechanism of action at both genomic and nongenomic level will be also discussed. As far as our knowledge goes, we are for the first time reporting neuroprotective effect and possible mechanism of action of these hormones in a single article.
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Affiliation(s)
- Ali Nasir Siddiqui
- Department of Pharmaceutical Medicine, Faculty of Pharmacy, Jamia Hamdard, New Delhi, India
| | - Nahida Siddiqui
- Department of Pharmacognosy and Phytochemistry, Faculty of Pharmacy, Jamia Hamdard, New Delhi, India
| | - Rashid Ali Khan
- Department of Pharmaceutical Medicine, Faculty of Pharmacy, Jamia Hamdard, New Delhi, India
| | - Abul Kalam
- Department of Pharmacology, Faculty of Pharmacy, Jamia Hamdard, New Delhi, India
| | - Nasimudeen R Jabir
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohammad Amjad Kamal
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.,Enzymoics, 7 Peterlee Place, Hebersham, NSW, Australia
| | | | - Shams Tabrez
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
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Locklear MN, Cohen AB, Jone A, Kritzer MF. Sex Differences Distinguish Intracortical Glutamate Receptor-Mediated Regulation of Extracellular Dopamine Levels in the Prefrontal Cortex of Adult Rats. Cereb Cortex 2016; 26:599-610. [PMID: 25260707 PMCID: PMC4712796 DOI: 10.1093/cercor/bhu222] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Executive functions of the prefrontal cortex (PFC) are sensitive to local dopamine (DA) levels. Although sex differences distinguish these functions and their dysfunction in disease, the basis for this is unknown. We asked whether sex differences might result from dimorphisms in the glutamatergic mechanisms that regulate PFC DA levels. Using antagonists selective for α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-d-aspartate (NMDA) receptors, we compared drug effects on in vivo microdialysis DA measurements in the PFC of adult male and female rats. We found that baseline DA levels were similar across sex, AMPA antagonism decreased PFC DA in both sexes, and NMDA antagonism increased DA in males but decreased DA in females. We also found that, at subseizure-producing drug levels, γ-aminobutyric acid (GABA)-A antagonism did not affect DA in either sex but that GABA-B antagonism transiently increased PFC DA in both sexes, albeit more so in females. Finally, when NMDA antagonism was coincident with GABA-B antagonism, PFC DA levels in males responded as if to GABA-B antagonism alone, whereas in females, DA effects mirrored those induced by NMDA antagonism. Taken together, these data suggest commonalities and fundamental differences in the intracortical amino acid transmitter mechanisms that regulate DA homeostasis in the male and female rat PFCs.
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Affiliation(s)
- M N Locklear
- Graduate Program in Neuroscience Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - A B Cohen
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - A Jone
- Graduate Program in Neuroscience Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - M F Kritzer
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA
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8
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Paragliola RM, Prete A, Kaplan PW, Corsello SM, Salvatori R. Treatment of hypopituitarism in patients receiving antiepileptic drugs. Lancet Diabetes Endocrinol 2015; 3:132-40. [PMID: 24898833 DOI: 10.1016/s2213-8587(14)70081-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Evidence suggests that there may be drug interactions between antiepileptic drugs and hormonal therapies, which can present a challenge to endocrinologists dealing with patients who have both hypopituitarism and neurological diseases. Data are scarce for this subgroup of patients; however, data for the interaction of antiepileptic drugs with the pituitary axis have shown that chronic use of many antiepileptic drugs, such as carbamazepine, oxcarbazepine, and topiramate, enhances hepatic cytochrome P450 3A4 (CYP3A4) activity, and can decrease serum concentrations of sex hormones. Other antiepileptic drugs increase sex hormone-binding globulin, which reduces the bioactivity of testosterone and estradiol. Additionally, the combined oestrogen-progestagen contraceptive pill might decrease lamotrigine concentrations, which could worsen seizure control. Moreover, sex hormones and their metabolites can directly act on neuronal excitability, acting as neurosteroids. Because carbamazepine and oxcarbazepine can enhance the sensitivity of renal tubules, a reduction in desmopressin dose might be necessary in patients with central diabetes insipidus. Although the effects of antiepileptic drugs in central hypothyroidism have not yet been studied, substantial evidence indicates that several antiepileptic drugs can increase thyroid hormone metabolism. However, although it is reasonable to expect a need for a thyroxine dose increase with some antiepileptic drugs, the effect of excessive thyroxine in lowering seizure threshold should also be considered. There are no reports of significant interactions between antiepileptic drugs and the efficacy of human growth hormone therapy, and few data are available for the effects of second-generation antiepileptic drugs on hypopituitarism treatment.
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Affiliation(s)
- Rosa Maria Paragliola
- Unit of Endocrinology, Facoltà di Medicina Università Cattolica del Sacro Cuore, Rome, Italy
| | - Alessandro Prete
- Unit of Endocrinology, Facoltà di Medicina Università Cattolica del Sacro Cuore, Rome, Italy
| | - Peter W Kaplan
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore MD, USA
| | | | - Roberto Salvatori
- Department of Medicine, Division of Endocrinology, Metabolism and Diabetes and Pituitary Center, Johns Hopkins University School of Medicine, Baltimore MD, USA.
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9
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Koppel BS, Harden CL. Gender issues in the neurobiology of epilepsy: A clinical perspective. Neurobiol Dis 2014; 72 Pt B:193-7. [DOI: 10.1016/j.nbd.2014.08.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 08/25/2014] [Accepted: 08/29/2014] [Indexed: 02/06/2023] Open
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10
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Carlson C, Dugan P, Kirsch HE, Friedman D. Sex differences in seizure types and symptoms. Epilepsy Behav 2014; 41:103-8. [PMID: 25461198 PMCID: PMC4267158 DOI: 10.1016/j.yebeh.2014.09.051] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 09/18/2014] [Accepted: 09/19/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND Despite the increasing interest in sex differences in disease manifestations and responses to treatment, very few data are available on sex differences in seizure types and semiology. The Epilepsy Phenome/Genome Project (EPGP) is a large-scale, multi-institutional, collaborative study that aims to create a comprehensive repository of detailed clinical information and DNA samples from a large cohort of people with epilepsy. We used this well-characterized cohort to explore differences in seizure types as well as focal seizure symptoms between males and females. METHODS We reviewed the EPGP database and identified individuals with generalized epilepsy of unknown etiology (GE) (n = 760; female: 446, male: 314), nonacquired focal epilepsy (NAFE) (n = 476; female: 245, male: 231), or both (n = 64; female: 33, male: 31). Demographic data along with characterization of seizure type and focal seizure semiologies were examined. RESULTS In GE, males reported atonic seizures more frequently than females (6.5% vs. 1.7%; p < 0.001). No differences were observed in other generalized seizure types. In NAFE, no sex differences were seen for seizure types with or without alteration of consciousness or progression to secondary generalization. Autonomic (16.4% vs. 26.6%; p = 0.005), psychic (26.7% vs. 40.3%; p = 0.001), and visual (10.3% vs. 19.9%; p = 0.002) symptoms were more frequently reported in females than males. Specifically, of psychic symptoms, more females than males endorsed déjà vu (p = 0.001) but not forced thoughts, derealization/depersonalization, jamais vu, or fear. With corrections for multiple comparisons, there were no significant differences in aphasic, motor, somatosensory, gustatory, olfactory, auditory, vertiginous, or ictal headache symptoms between sexes. CONCLUSIONS Significant differences between the sexes were observed in the reporting of atonic seizures, which were more common in males with GE, and for autonomic, visual, and psychic symptoms associated with NAFE, which were more common in females.
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Affiliation(s)
- Chad Carlson
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, USA.
| | - Patricia Dugan
- Department of Neurology, New York University School of Medicine, New York, NY, USA
| | - Heidi E Kirsch
- Department of Neurology and Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA
| | - Daniel Friedman
- Department of Neurology, New York University School of Medicine, New York, NY, USA
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11
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Activation of extrasynaptic GABA(A) receptors inhibits cyclothiazide-induced epileptiform activity in hippocampal CA1 neurons. Neurosci Bull 2014; 30:866-76. [PMID: 25260800 DOI: 10.1007/s12264-014-1466-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/17/2014] [Indexed: 12/20/2022] Open
Abstract
Extrasynaptic GABA(A) receptors (GABA(A)Rs)-mediated tonic inhibition is reported to involve in the pathogenesis of epilepsy. In this study, we used cyclothiazide (CTZ)-induced in vitro brain slice seizure model to explore the effect of selective activation of extrasynaptic GABA(A)Rs by 4,5,6,7-tetrahydroisoxazolo[5,4-c] pyridine-3-ol (THIP) on the CTZ-induced epileptiform activity in hippocampal neurons. Perfusion with CTZ dose-dependently induced multiple epileptiform peaks of evoked population spikes (PSs) in CA1 pyramidal neurons, and treatment with THIP (5 μmol/L) significantly reduced the multiple PS peaks induced by CTZ stimulation. Western blot showed that the δ-subunit of the GABA(A)R, an extrasynaptic specific GABA(A)R subunit, was also significantly down-regulated in the cell membrane 2 h after CTZ treatment. Our results suggest that the CTZ-induced epileptiform activity in hippocampal CA1 neurons is suppressed by the activation of extrasynaptic GABA(A)Rs, and further support the hypothesis that tonic inhibition mediated by extrasynaptic GABA(A)Rs plays a prominent role in seizure generation.
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12
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Scharfman HE, MacLusky NJ. Sex differences in the neurobiology of epilepsy: a preclinical perspective. Neurobiol Dis 2014; 72 Pt B:180-92. [PMID: 25058745 DOI: 10.1016/j.nbd.2014.07.004] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 07/08/2014] [Accepted: 07/11/2014] [Indexed: 10/25/2022] Open
Abstract
When all of the epilepsies are considered, sex differences are not always clear, despite the fact that many sex differences are known in the normal brain. Sex differences in epilepsy in laboratory animals are also unclear, although robust effects of sex on seizures have been reported, and numerous effects of gonadal steroids have been shown throughout the rodent brain. Here we discuss several reasons why sex differences in seizure susceptibility are unclear or are difficult to study. Examples of robust sex differences in laboratory rats, such as the relative resistance of adult female rats to the chemoconvulsant pilocarpine compared to males, are described. We also describe a novel method that has shed light on sex differences in neuropathology, which is a relatively new technique that will potentially contribute to sex differences research in the future. The assay we highlight uses the neuronal nuclear antigen NeuN to probe sex differences in adult male and female rats and mice. In females, weak NeuN expression defines a sex difference that previous neuropathological studies have not described. We also show that in adult rats, social isolation stress can obscure the normal effects of 17β-estradiol to increase excitability in area CA3 of the hippocampus. These data underscore the importance of controlling behavioral stress in studies of seizure susceptibility in rodents and suggest that behavioral stress may be one factor that has led to inconsistencies in outcomes of sex differences research. These and other issues have made it difficult to translate our increasing knowledge about the effects of gonadal hormones on the brain to improved treatment for men and women with epilepsy.
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Affiliation(s)
- Helen E Scharfman
- Department of Child & Adolescent Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA; Department of Physiology & Neuroscience, New York University Langone Medical Center, New York, NY 10016, USA; Department of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA.
| | - Neil J MacLusky
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
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Frye CA, Koonce CJ, Walf AA. Novel receptor targets for production and action of allopregnanolone in the central nervous system: a focus on pregnane xenobiotic receptor. Front Cell Neurosci 2014; 8:106. [PMID: 24782710 PMCID: PMC3988369 DOI: 10.3389/fncel.2014.00106] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 03/25/2014] [Indexed: 12/05/2022] Open
Abstract
Neurosteroids are cholesterol-based hormones that can be produced in the brain, independent of secretion from peripheral endocrine glands, such as the gonads and adrenals. A focus in our laboratory for over 25 years has been how production of the pregnane neurosteroid, allopregnanolone, is regulated and the novel (i.e., non steroid receptor) targets for steroid action for behavior. One endpoint of interest has been lordosis, the mating posture of female rodents. Allopregnanolone is necessary and sufficient for lordosis, and the brain circuitry underlying it, such as actions in the midbrain ventral tegmental area (VTA), has been well-characterized. Published and recent findings supporting a dynamic role of allopregnanolone are included in this review. First, contributions of ovarian and adrenal sources of precursors of allopregnanolone, and the requisite enzymatic actions for de novo production in the central nervous system will be discussed. Second, how allopregnanolone produced in the brain has actions on behavioral processes that are independent of binding to steroid receptors, but instead involve rapid modulatory actions via neurotransmitter targets (e.g., γ-amino butyric acid-GABA, N-methyl-D-aspartate- NMDA) will be reviewed. Third, a recent focus on characterizing the role of a promiscuous nuclear receptor, pregnane xenobiotic receptor (PXR), involved in cholesterol metabolism and expressed in the VTA, as a target for allopregnanolone and how this relates to both actions and production of allopregnanolone will be addressed. For example, allopregnanolone can bind PXR and knocking down expression of PXR in the midbrain VTA attenuates actions of allopregnanolone via NMDA and/or GABAA for lordosis. Our understanding of allopregnanolone’s actions in the VTA for lordosis has been extended to reveal the role of allopregnanolone for broader, clinically-relevant questions, such as neurodevelopmental processes, neuropsychiatric disorders, epilepsy, and aging.
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Affiliation(s)
- Cheryl A Frye
- Department of Psychology, The University at Albany-SUNY Albany, NY, USA ; Department of Biological Sciences, The University at Albany-SUNY Albany, NY, USA ; The Centers for Neuroscience, The University at Albany-SUNY Albany, NY, USA ; Life Sciences Research, The University at Albany-SUNY Albany, NY, USA ; Department of Chemistry and Biochemistry, The University of Alaska-Fairbanks Fairbanks, AK, USA ; Institute of Arctic Biology, The University of Alaska-Fairbanks Fairbanks, AK, USA ; IDeA Network of Biomedical Excellence (INBRE), The University of Alaska-Fairbanks Fairbanks, AK, USA
| | - Carolyn J Koonce
- Department of Psychology, The University at Albany-SUNY Albany, NY, USA ; Institute of Arctic Biology, The University of Alaska-Fairbanks Fairbanks, AK, USA ; IDeA Network of Biomedical Excellence (INBRE), The University of Alaska-Fairbanks Fairbanks, AK, USA
| | - Alicia A Walf
- Department of Psychology, The University at Albany-SUNY Albany, NY, USA ; Institute of Arctic Biology, The University of Alaska-Fairbanks Fairbanks, AK, USA ; IDeA Network of Biomedical Excellence (INBRE), The University of Alaska-Fairbanks Fairbanks, AK, USA
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Schopper M, Fleckenstein J, Irnich D. Geschlechtsspezifische Aspekte bei akuten und chronischen Schmerzen. Schmerz 2013; 27:456-66. [PMID: 24026807 DOI: 10.1007/s00482-013-1361-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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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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Abstract
Complex, multidirectional interactions between hormones, seizures, and the medications used to control them can present a challenge for clinicians treating patients with epilepsy. Many hormones act as neurosteroids, modulating brain excitability via direct binding sites. Thus, changes in endogenous or exogenous hormone levels can affect the occurrence of seizures directly as well as indirectly through pharmacokinetic effects that alter the concentrations of antiepileptic drugs. The underlying structural and physiological brain abnormalities of epilepsy and the metabolic activity of antiepileptic drugs can adversely affect hypothalamic and gonadal functioning. Knowledge of these complex interactions has increased and can now be incorporated in meaningful treatment approaches for men and women with epilepsy.
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Affiliation(s)
- Cynthia L Harden
- Division of Epilepsy and Electroencephalography, Hofstra North Shore-LIJ School of Medicine at Hofstra University, Hempstead, NY, USA.
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Schopper M, Bäumler PI, Fleckenstein J, Irnich D. [Gender aspects in anesthesia : modified approach in research and treatment?]. Anaesthesist 2012; 61:288-98. [PMID: 22526740 DOI: 10.1007/s00101-012-2013-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Gender differences can have a relevant influence on the perioperative outcome as male and female patients are affected differently by adverse events, e.g. side effects of drugs. Furthermore, differences relating to specific drug effects, comorbidities and outcome after anesthesia or intensive care have been demonstrated. There seems to be a gender bias in diagnosis and therapy. While the knowledge regarding this field is still growing certain aspects have already been integrated into clinical practice: prevention of postoperative nausea and vomiting (PONV), target controlled infusion (TCI) model and male only policy with production of blood products. There is a need to study the influence of gender, age and race in order to optimize treatment towards a more individualized therapy. This article highlights already identified differences and discusses potential underlying mechanisms.
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Affiliation(s)
- M Schopper
- Klinik für Anästhesiologie, Klinikum der Universität München, Campus Innenstadt, München, Deutschland.
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Abstract
BACKGROUND Non-convulsive seizures have been reported to be common in neurocritical care patients. Many jurisdictions do not have sufficient resources to enable routine continuous electroencephalography (cEEG) and instead use primarily intermittent EEG, for which the diagnostic yield remains uncertain. Determining risk factors for epileptiform activity and seizures could help identify patients who might particularly benefit from EEG monitoring. METHODS We performed a cohort study involving neurocritical care patients with admission Glascow Coma Scale (GCS) scores ≤ 12, who underwent ≥ 1 EEG. EEGs were reviewed for presence of interictal discharges, periodic epileptiform discharges (PEDs), and seizures. Multivariate analysis was used to identify predictors of these findings and to describe their prognostic implications. RESULTS 393 patients met inclusion criteria. 34 underwent cEEG, usually because epileptiform activity was first detected on a routine EEG. The prevalence of PEDs or electrographic seizures was 13%, and was highest with anoxic encephalopathy and central nervous system infections. Other independent predictors for epileptiform activity included a history of convulsive seizure(s), increasing age, deeper coma, and female gender. Although patients with epileptiform activity had higher mortality, this association disappeared after adjustment for confounders. CONCLUSION Approximately 7-8 neurocritical care patients must undergo intermittent EEG monitoring in order to diagnose one with PEDs or seizures. The predictors we identified could potentially help guide use of resources. Repeated intermittent studies, or cEEG, should be considered in patients with multiple risk factors, or when interictal discharges are identified on an initial EEG. It remains unclear whether aggressive prevention and treatment of electrographic seizures improves neurologic outcomes.
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Effect of systemic kynurenine on cortical spreading depression and its modulation by sex hormones in rat. Exp Neurol 2012; 236:207-14. [PMID: 22587906 DOI: 10.1016/j.expneurol.2012.05.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 04/19/2012] [Accepted: 05/05/2012] [Indexed: 12/29/2022]
Abstract
BACKGROUND The aura symptoms in migraine are most likely due to cortical spreading depression (CSD). CSD is favored by NMDA receptor activation and increased cortical excitability. The latter probably explains why migraine with aura may appear when estrogen levels are high, like during pregnancy. Kynurenic acid, a derivative of tryptophan metabolism, is an endogenous NMDA receptor antagonist whose cerebral concentrations can be augmented by systemic administration of its precursor L-kynurenine. OBJECTIVE To determine if exogenous administration of L-kynurenine is able to influence KCl-induced CSD in rat, if the effect is sex-dependent and if it differs in females between the phases of the estrous cycle. METHODS Adult Sprague-Dawley rats (n=8/group) received intraperitoneal (i.p.) injections of L-kynurenine (L-KYN, 300 mg/kg), L-KYN combined with probenecid (L-KYN+PROB) that increases cortical concentration of KYNA by blocking its excretion from the central nervous system, probenecid alone (PROB, 200 mg/kg) or NaCl. Cortical kynurenic acid concentrations were determined by HPLC (n=7). Thirty minutes after the injections, CSDs were elicited by application of 1M KCl over the occipital cortex and recorded by DC electrocorticogram. In NaCl and L-KYN groups, supplementary females were added and CSD frequency was analyzed respective to the phases of the estrous cycle determined by vaginal smears. RESULTS In both sexes, PROB, L-KYN and L-KYN+PROB increased cortical kynurenic acid level. PROB, L-KYN and L-KYN+PROB with increasing potency decreased CSD frequency in female rats, while in males such an effect was significant only for L-KYN+PROB. The inhibitory effect of L-KYN on CSD frequency in females was most potent in diestrus. CONCLUSION L-Kynurenine administration suppresses CSD, most likely by increasing kynurenic acid levels in the cortex. Females are more sensitive to this suppressive effect of L-kynurenine than males. These results emphasize the role of sex hormones in migraine and open interesting novel perspectives for its preventive treatment.
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Effect of medroxyprogesterone on development of pentylenetetrazole-induced kindling in mice. Neuroscience 2012; 207:283-7. [DOI: 10.1016/j.neuroscience.2012.01.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 01/13/2012] [Accepted: 01/14/2012] [Indexed: 11/21/2022]
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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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Elucidating the Complex Interactions between Stress and Epileptogenic Pathways. Cardiovasc Psychiatry Neurol 2011; 2011:461263. [PMID: 21547249 PMCID: PMC3085328 DOI: 10.1155/2011/461263] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2010] [Accepted: 01/22/2011] [Indexed: 11/24/2022] Open
Abstract
Clinical and experimental data suggest that stress contributes to the pathology of epilepsy. We review mechanisms by which stress, primarily via stress hormones, may exacerbate epilepsy, focusing on the intersection between stress-induced pathways and the progression of pathological events that occur before, during, and after the onset of epileptogenesis. In addition to this temporal nuance, we discuss other complexities in stress-epilepsy interactions, including the role of blood-brain barrier dysfunction, neuron-glia interactions, and inflammatory/cytokine pathways that may be protective or damaging depending on context. We advocate the use of global analytical tools, such as microarray, in support of a shift away from a narrow focus on seizures and towards profiling the complex, early process of epileptogenesis, in which multiple pathways may interact to dictate the ultimate onset of chronic, recurring seizures.
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Nelson NR, Bird IM, Behan M. Testosterone restores respiratory long term facilitation in old male rats by an aromatase-dependent mechanism. J Physiol 2010; 589:409-21. [PMID: 21078587 DOI: 10.1113/jphysiol.2010.198200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Steroidal sex hormones play an important role in the neural control of breathing. Previous studies in our laboratory have shown that gonadectomy in young male rats (3 months) eliminates a form of respiratory plasticity induced by intermittent hypoxia, known as long term facilitation (LTF). Testosterone replenishment restores LTF in gonadectomized male rats, and this is dependent on the conversion of testosterone to oestradiol by aromatase. By middle age (12 months), male rats no longer exhibit LTF of hypoglossal motor output; phrenic LTF is significantly reduced, and this persists into old age. We tested the hypothesis that LTF can be restored in old male rats by administration of testosterone. Intact Fischer 344 rats (>20 months) were implanted with Silastic tubing containing testosterone (T), T plus an aromatase inhibitor (T+ADT), or 5α-dihydrotestosterone (DHT), a form of testosterone not converted to oestradiol. One week post-surgery, LTF of hypoglossal and phrenic motor output was measured. By comparison with control rats, hypoglossal LTF was increased in testosterone-treated rats, with levels approaching that of normal young rats. LTF was not restored in T+ADT or DHT-treated rats. Aromatase levels in hypoglossal and phrenic nuclei did not change with age. As serum testosterone levels did not decline with age, local bioavailability of testosterone in old rats may be a limiting factor in the expression of this form of respiratory plasticity. Our findings suggest that testosterone supplementation could potentially be used to enhance upper airway control in the elderly.
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Affiliation(s)
- N R Nelson
- Department of Comparative Biosciences, University of Wisconsin, Madison, WI 53706-1102, USA
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