The Contribution of Normal Pregnancy to Eclampsia.
Eclampsia, clinically defined as unexplained seizure in a woman with preeclampsia, is a life threatening complication unique to the pregnant state. However, a subpopulation of women with seemingly uncomplicated pregnancies experience de novo seizure without preeclamptic signs or symptoms, suggesting...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2015-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC4517916?pdf=render |
| _version_ | 1818109272739807232 |
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| author | Abbie Chapman Johnson Keith J Nagle Sarah M Tremble Marilyn J Cipolla |
| author_facet | Abbie Chapman Johnson Keith J Nagle Sarah M Tremble Marilyn J Cipolla |
| author_sort | Abbie Chapman Johnson |
| collection | DOAJ |
| description | Eclampsia, clinically defined as unexplained seizure in a woman with preeclampsia, is a life threatening complication unique to the pregnant state. However, a subpopulation of women with seemingly uncomplicated pregnancies experience de novo seizure without preeclamptic signs or symptoms, suggesting pregnancy alone may predispose the brain to seizure. Here, we hypothesized that normal pregnancy lowers seizure threshold and investigated mechanisms by which pregnancy may affect seizure susceptibility, including neuroinflammation and plasticity of gamma-aminobutyric acid type A receptor (GABAAR) subunit expression. Seizure threshold was determined by quantifying the amount of pentylenetetrazole (PTZ) required to elicit electrical seizure in Sprague Dawley rats that were either nonpregnant (Nonpreg, n = 7) or pregnant (Preg; d20, n = 6). Seizure-induced vasogenic edema was also measured. Further, activation of microglia, a measure of neuroinflammation (n = 6-8/group), and GABAAR δ- and γ2-subunit protein expression in the cerebral cortex and hippocampus (n = 6/group) was determined. Seizure threshold was lower in Preg compared to Nonpreg rats (36.7±9.6 vs. 65.0±14.5 mg/kg PTZ; p<0.01) that was associated with greater vasogenic edema formation (78.55±0.11 vs. 78.04±0.19% water; p<0.05). The % of active microglia was similar between groups; however, pregnancy was associated with downregulation of cortical GABAAR-δ and hippocampal GABAAR-γ2 expression. Overall, pregnancy appears to be a state of increased seizure susceptibility that is not due to neuroinflammation, but rather is associated with reduced expression of GABAAR subunits and greater edema. Understanding neurophysiological changes occurring in normal pregnancy could allow for better prevention and management of de novo seizure, including pathologic states such as eclampsia. |
| first_indexed | 2024-12-11T02:28:37Z |
| format | Article |
| id | doaj.art-e569e1d6c1d5400eb3d0da760bf20373 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-11T02:28:37Z |
| publishDate | 2015-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-e569e1d6c1d5400eb3d0da760bf203732022-12-22T01:23:53ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-01107e013395310.1371/journal.pone.0133953The Contribution of Normal Pregnancy to Eclampsia.Abbie Chapman JohnsonKeith J NagleSarah M TrembleMarilyn J CipollaEclampsia, clinically defined as unexplained seizure in a woman with preeclampsia, is a life threatening complication unique to the pregnant state. However, a subpopulation of women with seemingly uncomplicated pregnancies experience de novo seizure without preeclamptic signs or symptoms, suggesting pregnancy alone may predispose the brain to seizure. Here, we hypothesized that normal pregnancy lowers seizure threshold and investigated mechanisms by which pregnancy may affect seizure susceptibility, including neuroinflammation and plasticity of gamma-aminobutyric acid type A receptor (GABAAR) subunit expression. Seizure threshold was determined by quantifying the amount of pentylenetetrazole (PTZ) required to elicit electrical seizure in Sprague Dawley rats that were either nonpregnant (Nonpreg, n = 7) or pregnant (Preg; d20, n = 6). Seizure-induced vasogenic edema was also measured. Further, activation of microglia, a measure of neuroinflammation (n = 6-8/group), and GABAAR δ- and γ2-subunit protein expression in the cerebral cortex and hippocampus (n = 6/group) was determined. Seizure threshold was lower in Preg compared to Nonpreg rats (36.7±9.6 vs. 65.0±14.5 mg/kg PTZ; p<0.01) that was associated with greater vasogenic edema formation (78.55±0.11 vs. 78.04±0.19% water; p<0.05). The % of active microglia was similar between groups; however, pregnancy was associated with downregulation of cortical GABAAR-δ and hippocampal GABAAR-γ2 expression. Overall, pregnancy appears to be a state of increased seizure susceptibility that is not due to neuroinflammation, but rather is associated with reduced expression of GABAAR subunits and greater edema. Understanding neurophysiological changes occurring in normal pregnancy could allow for better prevention and management of de novo seizure, including pathologic states such as eclampsia.http://europepmc.org/articles/PMC4517916?pdf=render |
| spellingShingle | Abbie Chapman Johnson Keith J Nagle Sarah M Tremble Marilyn J Cipolla The Contribution of Normal Pregnancy to Eclampsia. PLoS ONE |
| title | The Contribution of Normal Pregnancy to Eclampsia. |
| title_full | The Contribution of Normal Pregnancy to Eclampsia. |
| title_fullStr | The Contribution of Normal Pregnancy to Eclampsia. |
| title_full_unstemmed | The Contribution of Normal Pregnancy to Eclampsia. |
| title_short | The Contribution of Normal Pregnancy to Eclampsia. |
| title_sort | contribution of normal pregnancy to eclampsia |
| url | http://europepmc.org/articles/PMC4517916?pdf=render |
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