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Tang G, Zhou H, Zeng C, Jiang Y, Li Y, Hou L, Liao K, Tan Z, Wu H, Tang Y, Cheng Y, Ling X, Guo Q, Xu H. Alterations of apparent diffusion coefficient from ultra high b-values in the bilateral thalamus and striatum in MRI-negative drug-resistant epilepsy. Epilepsia Open 2024; 9:1515-1525. [PMID: 38943548 PMCID: PMC11296122 DOI: 10.1002/epi4.12990] [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: 06/06/2023] [Revised: 04/01/2024] [Accepted: 05/26/2024] [Indexed: 07/01/2024] Open
Abstract
OBJECTIVE Subcortical nuclei such as the thalamus and striatum have been shown to be related to seizure modulation and termination, especially in drug-resistant epilepsy. Enhance diffusion-weighted imaging (eDWI) technique and tri-component model have been used in previous studies to calculate apparent diffusion coefficient from ultra high b-values (ADCuh). This study aimed to explore the alterations of ADCuh in the bilateral thalamus and striatum in MRI-negative drug-resistant epilepsy. METHODS Twenty-nine patients with MRI-negative drug-resistant epilepsy and 18 healthy controls underwent eDWI scan with 15 b-values (0-5000 s/mm2). The eDWI parameters including standard ADC (ADCst), pure water diffusion (D), and ADCuh were calculated from the 15 b-values. Regions-of-interest (ROIs) analyses were conducted in the bilateral thalamus, caudate nucleus, putamen, and globus pallidus. ADCst, D, and ADCuh values were compared between the MRI-negative drug-resistant epilepsy patients and controls using multivariate generalized linear models. Inter-rater reliability was assessed using the intra-class correlation coefficient (ICC) and Bland-Altman (BA) analysis. False discovery rate (FDR) method was applied for multiple comparisons correction. RESULTS ADCuh values in the bilateral thalamus, caudate nucleus, putamen, and globus pallidus in MRI-negative drug-resistant epilepsy were significantly higher than those in the healthy control subjects (all p < 0.05, FDR corrected). SIGNIFICANCE The alterations of the ADCuh values in the bilateral thalamus and striatum in MRI-negative drug-resistant epilepsy might reflect abnormal membrane water permeability in MRI-negative drug-resistant epilepsy. ADCuh might be a sensitive measurement for evaluating subcortical nuclei-related brain damage in epilepsy patients. PLAIN LANGUAGE SUMMARY This study aimed to explore the alterations of apparent diffusion coefficient calculated from ultra high b-values (ADCuh) in the subcortical nuclei such as the bilateral thalamus and striatum in MRI-negative drug-resistant epilepsy. The bilateral thalamus and striatum showed higher ADCuh in epilepsy patients than healthy controls. These findings may add new evidences of subcortical nuclei abnormalities related to water and ion hemostasis in epilepsy patients, which might help to elucidate the underlying epileptic neuropathophysiological mechanisms and facilitate the exploration of therapeutic targets.
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Affiliation(s)
- Guixian Tang
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Hailing Zhou
- Department of RadiologyCentral People's Hospital of ZhanjiangZhanjiangChina
| | - Chunyuan Zeng
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Yuanfang Jiang
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Ying Li
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Lu Hou
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Kai Liao
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Zhiqiang Tan
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Huanhua Wu
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Yongjin Tang
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Yong Cheng
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Xueying Ling
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
| | - Qiang Guo
- Epilepsy Center, Guangdong 999 Brain HospitalAffiliated Brain Hospital of Jinan UniversityGuangzhouChina
| | - Hao Xu
- Department of Nuclear Medicine, PET/CT‐MRI Center, Center of Cyclotron and PET RadiopharmaceuticalsThe First Affiliated Hospital of Jinan UniversityGuangzhouChina
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Bonosi L, Benigno UE, Musso S, Giardina K, Gerardi RM, Brunasso L, Costanzo R, Paolini F, Buscemi F, Avallone C, Gulino V, Iacopino DG, Maugeri R. The Role of Aquaporins in Epileptogenesis-A Systematic Review. Int J Mol Sci 2023; 24:11923. [PMID: 37569297 PMCID: PMC10418736 DOI: 10.3390/ijms241511923] [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: 05/25/2023] [Revised: 07/20/2023] [Accepted: 07/23/2023] [Indexed: 08/13/2023] Open
Abstract
Aquaporins (AQPs) are a family of membrane proteins involved in the transport of water and ions across cell membranes. AQPs have been shown to be implicated in various physiological and pathological processes in the brain, including water homeostasis, cell migration, and inflammation, among others. Epileptogenesis is a complex and multifactorial process that involves alterations in the structure and function of neuronal networks. Recent evidence suggests that AQPs may also play a role in the pathogenesis of epilepsy. In animal models of epilepsy, AQPs have been shown to be upregulated in regions of the brain that are involved in seizure generation, suggesting that they may contribute to the hyperexcitability of neuronal networks. Moreover, genetic studies have identified mutations in AQP genes associated with an increased risk of developing epilepsy. Our review aims to investigate the role of AQPs in epilepsy and seizure onset from a pathophysiological point of view, pointing out the potential molecular mechanism and their clinical implications.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Rosario Maugeri
- Neurosurgical Clinic, AOUP “Paolo Giaccone”, Post Graduate Residency Program in Neurologic Surgery, Department of Biomedicine Neurosciences and Advanced Diagnostics, School of Medicine, University of Palermo, 90127 Palermo, Italy; (L.B.); (U.E.B.); (S.M.); (K.G.); (R.M.G.); (L.B.); (R.C.); (F.P.); (F.B.); (C.A.); (V.G.); (D.G.I.)
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Lee JW, Norden AD, Ligon KL, Golby AJ, Beroukhim R, Quackenbush J, Wells W, Oelschlager K, Maetzold D, Wen PY. Tumor associated seizures in glioblastomas are influenced by survival gene expression in a region-specific manner: a gene expression imaging study. Epilepsy Res 2014; 108:843-52. [PMID: 24690158 DOI: 10.1016/j.eplepsyres.2014.02.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 01/31/2014] [Accepted: 02/28/2014] [Indexed: 11/15/2022]
Abstract
Tumor associated seizures (TAS) are common and cause significant morbidity. Both imaging and gene expression features play significant roles in determining TAS, with strong interactions between them. We describe gene expression imaging tools which allow mapping of brain regions where gene expression has significant influence on TAS, and apply these methods to study 77 patients who underwent surgical evaluation for supratentorial glioblastomas. Tumor size and location were measured from MRI scans. A 9-set gene expression profile predicting long-term survivors was obtained from RNA derived from formalin-fixed paraffin embedded tissue. A total of 32 patients (42%) experienced preoperative TAS. Tumor volume was smaller (31.1 vs. 58.8 cubic cm, p<0.001) and there was a trend toward median survival being higher (48.4 vs. 32.7 months, p=0.055) in patients with TAS. Although the expression of only OLIG2 was significantly lower in patients with TAS in a groupwise analysis, gene expression imaging analysis revealed regions with significantly lower expression of OLIG2 and RTN1 in patients with TAS. Gene expression imaging is a powerful technique that demonstrates that the influence of gene expression on TAS is highly region specific. Regional variability should be evaluated with any genomic or molecular markers of solid brain lesions.
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Affiliation(s)
- Jong Woo Lee
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, United States.
| | - Andrew D Norden
- Center for Neuro-oncology, Dana Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, United States
| | - Keith L Ligon
- Department of Pathology, Brigham and Women's Hospital, Boston Children's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA 02115, United States; Department of Medical Oncology, Center for Molecular Oncologic Pathology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02115, United States
| | - Alexandra J Golby
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, United States
| | - Rameen Beroukhim
- Center for Neuro-oncology, Dana Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, United States
| | - John Quackenbush
- Department of Biostatistics, Dana Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, United States
| | - William Wells
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, United States
| | - Kristen Oelschlager
- Castle Biosciences Inc., 3330N 2nd Street, Suite 207, Phoenix, AZ 85012, United States
| | - Derek Maetzold
- Castle Biosciences Inc., 3330N 2nd Street, Suite 207, Phoenix, AZ 85012, United States
| | - Patrick Y Wen
- Center for Neuro-oncology, Dana Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, United States
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Abstract
Deep brain stimulation (DBS) is a method of treatment utilized to control medically refractory epilepsy (RE). Patients with medically refractory epilepsy who do not achieve satisfactory control of seizures with pharmacological treatment or surgical resection of the epileptic focus and those who do not qualify for surgery could benefit from DBS. The most frequently used stereotactic targets for DBS are the anterior thalamic nucleus, subthalamic nucleus, central-medial thalamic nucleus, hippocampus, amygdala and cerebellum. The DBS is believed to be an effective method of treatment for various types of epilepsy among adults and adolescents. Side effects may be associated with implantation of electrodes and with the stimulation itself. An increasing number of publications and growing interest in DBS application for RE may result in standardization of the qualification and treatment protocol for RE with DBS.
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Affiliation(s)
- Tomasz Tykocki
- Department of Neurosurgery, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Tomasz Mandat
- Department of Neurosurgery, Institute of Oncology, Warsaw, Poland
| | | | - Henryk Koziara
- Department of Neurosurgery, Institute of Oncology, Warsaw, Poland
| | - Paweł Nauman
- Department of Neurosurgery, Institute of Psychiatry and Neurology, Warsaw, Poland
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Characteristics of aquaporin expression surrounding senile plaques and cerebral amyloid angiopathy in Alzheimer disease. J Neuropathol Exp Neurol 2012; 71:750-9. [PMID: 22805778 DOI: 10.1097/nen.0b013e3182632566] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Senile plaques (SPs) containing amyloid β peptide (Aβ) 1-42 are the major species present in Alzheimer disease (AD), whereas Aβ1-40 is the major constituent of arteriolar walls affected by cerebral amyloid angiopathy. The water channel proteins astrocytic aquaporin 1 (AQP1) and aquaporin 4 (AQP4) are known to be abnormally expressed in AD brains, but the expression of AQPs surrounding SPs and cerebral amyloid angiopathy has not been described in detail. Here, we investigated whether AQP expression is associated with each species of Aβ deposited in human brains affected by either sporadic or familial AD. Immunohistochemical analysis demonstrated more numerous AQP1-positive reactive astrocytes in the AD cerebral cortex than in controls, located close to Aβ42- or Aβ40-positive SPs. In AD cases, however, AQP1-positive astrocytes were not often observed in Aβ-rich areas, and there was a significant negative correlation between the levels of AQP1 and Aβ42 assessed semiquantitatively. We also found that Aβ plaque-like AQP4 was distributed in association with Aβ42- or Aβ40-positive SPs and that the degree of AQP4 expression around Aβ40-positive vessels was variable. These findings suggest that a defined population of AQP1-positive reactive astrocytes may modify Aβ deposition in the AD brain, whereas the Aβ deposition process might alter astrocytic expression of AQP4.
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Paul L, Madan M, Rammling M, Chigurupati S, Chan SL, Pattisapu JV. Expression of aquaporin 1 and 4 in a congenital hydrocephalus rat model. Neurosurgery 2011; 68:462-73. [PMID: 21135737 DOI: 10.1227/neu.0b013e3182011860] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Hydrocephalus occurs because of an imbalance of bulk fluid flow in the brain, and aquaporins (AQPs) play pivotal roles in cerebral water movement as essential mediators during edema and fluid accumulation. AQP1 is a water channel found in the choroid plexus (CP), and AQP4 is expressed at the brain-CSF interfaces and astrocytic end feet; excessive fluid accumulation may involve expression of changes in these AQPs during various stages of hydrocephalus. OBJECTIVE To determine the alterations of CP AQP1 expression in congenital hydrocephalus; detect hydrocephalus-induced AQP1 expression in the cortical parenchyma, ependyma, and pia mater of hydrocephalic animals; and evaluate AQP4 expression in congenital hydrocephalus through progressive stages of the condition. METHODS We evaluated differential expression of AQPs 1 and 4 in the congenital hydrocephalus Texas rat at postnatal days 5, 10, and 26 in isolated CP and cortex by enzyme-linked immunosorbent assay, Western blot, quantitative reverse transcriptase polymerase chain reaction, and immunohistochemistry. RESULTS The CP exhibited a 34% decrease in AQP1 expression in young hydrocephalic pups (postnatal days 5 and 10), which became normal (postnatal day 26) just before death. With advancing hydrocephalus, expression of AQPs 1 and 4 increased at the brain-CSF interfaces; AQP1 was localized to the endothelium of cortical capillaries with increased AQP4 expression in surrounding astrocytes end feet. AQP1 expression level was increased in the pia mater, with prominent AQP4 expression in the subpial layers. Subependymal capillaries expressed AQP1 in the endothelium, with increasing AQP4 expression in surrounding astrocytes. Hydrocephalic animals (postnatal day 26) had significant nonendothelial (CD34) AQP1 expression in the septal nucleus of the basal forebrain, an area affected by increased intracranial pressure. CONCLUSION Biphasic AQP1 expression in the CP with increased AQPs 1 and 4 at the brain-fluid interfaces may indicate compensatory mechanisms to regulate choroidal cerebrospinal fluid secretion and increase parenchymal fluid absorption in the high-pressure hydrocephalic condition.
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Affiliation(s)
- Leena Paul
- Burnett School of Biomedical Science, College of Medicine, University of Central Florida Orlando, Florida, USA.
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Fang M, Xi ZQ, Wu Y, Wang XF. A new hypothesis of drug refractory epilepsy: neural network hypothesis. Med Hypotheses 2011; 76:871-6. [PMID: 21429675 DOI: 10.1016/j.mehy.2011.02.039] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 02/16/2011] [Accepted: 02/20/2011] [Indexed: 01/16/2023]
Abstract
Drug refractory is an important clinical problem in epilepsy, affecting a substantial number of patients globally. Mechanisms underlying drug refractory need to be understood to develop rational therapies. Current two prevailing theories on drug refractory epilepsy (DRE) include the target hypothesis and the transporter hypothesis. However, those hypotheses could not be adequate to explain the mechanisms of all the DRE. Thus, we propose another possible mechanism of DRE, which is neural network hypothesis. It is hypothesized that seizure-induced alterations of brain plasticity including axonal sprouting, synaptic reorganization, neurogenesis and gliosis could contribute to the formation of abnormal neural network, which has not only avoided the inhibitory effect of endogenous antiepileptic system but also prevented the traditional antiepileptic drugs from entering their targets, eventually leading to DRE. We will illustrate this hypothesis at molecular and structural level based on our recent studies and other related researches.
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Affiliation(s)
- Min Fang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 You Yi Road, Chongqing 400016, China
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Oliva AA, Kang Y, Truettner JS, Sanchez-Molano J, Furones C, Yool AJ, Atkins CM. Fluid-percussion brain injury induces changes in aquaporin channel expression. Neuroscience 2011; 180:272-9. [PMID: 21329742 DOI: 10.1016/j.neuroscience.2011.02.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 02/07/2011] [Accepted: 02/08/2011] [Indexed: 11/26/2022]
Abstract
Edema, the accumulation of excess fluid, is a major pathological change in the brain that contributes significantly to pathology and mortality after moderate to severe brain injury. Edema is regulated by aquaporin (AQP) channels which transport water across cellular membranes. Six AQPs are found in the brain (1, 3, 4, 5, 8, and 9), and previous studies have found that AQP4 is regulated after traumatic brain injury (TBI). To further understand how AQPs contribute to brain edema, we investigated whether expression of AQP1, 3, and 9 are also regulated after TBI. Adult male Sprague Dawley rats received moderate parasagittal fluid-percussion brain injury (FPI) or sham surgery. After induction of FPI, the injured, ipsilateral parietal cortex and hippocampus were dissected and analyzed by Western blotting. We observed a small decrease in AQP3 and 4 levels at 7 days after FPI in the ipsilateral, parietal cortex. Both AQP1 and 9 significantly increased within 30 min post-injury and remained elevated for up to 6 h in the ipsilateral, parietal cortex. Aqp1 and 9 mRNA levels were also significantly increased at 30 min post-FPI. Administration of an AQP1 and 4 antagonist, AqB013, non-significantly increased brain water content in sham, non-injured animals, and did not prevent edema formation 24 h after trauma in either the parietal cortex or hippocampus. These results indicate that Aqp1 and 9 mRNA and protein levels increase after moderate parasagittal FPI and that an inhibitor of AQP1 and 4 does not decrease edema after moderate parasagittal FPI.
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Affiliation(s)
- A A Oliva
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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Zelenina M. Regulation of brain aquaporins. Neurochem Int 2010; 57:468-88. [DOI: 10.1016/j.neuint.2010.03.022] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 03/21/2010] [Accepted: 03/31/2010] [Indexed: 01/27/2023]
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Wang Y, Liu PP, Li LY, Zhang HM, Li T. Hypothermia reduces brain edema, spontaneous recurrent seizure attack, and learning memory deficits in the kainic acid treated rats. CNS Neurosci Ther 2010; 17:271-80. [PMID: 21951365 DOI: 10.1111/j.1755-5949.2010.00168.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
AIMS It is unknown whether hypothermia can disrupt the progress of epileptogenesis. The present study aimed to determine the effect of hypothermia on brain edema and epileptogenesis and to establish whether brain edema is associated with epileptogenesis after severe status epilepticus (SE). METHODOLOGY Rats were injected with a single dose of Kainic acid (KA) to produce either chronic epileptic rats (rats with spontaneous recurrent seizure, SRS) or rats without spontaneous recurrent seizure (no-SRS rats). A second KA injection was used to induce SE in SRS rats and in no-SRS rats. The number of SRS was counted and the brain edema induced by SE was assessed by brain water content measurement. The cognitive function was assessed by the radial-arm maze (RAM) test. RESULTS A second KA injection resulted in brain edema that was more severe in SRS rats than in no-SRS rats. After second injection of KA, hypothermia treatment attenuated the KA induced brain edema and reduced the SRS attack in SRS rats. Additionally cognitive function was better in hypothermia-treated SRS rats than in nomothermia treated SRS rats 1 month after the second KA injection. CONCLUSIONS Hypothermia treatment immediately after SE not only exhibited protective effects against the chronic spontaneous recurrent convulsant seizures but also improved cognitive function. These antiepileptogenic properties of hypothermia may be related to its attenuating effect on brain edema induced by SE. They therefore suggest that brain edema may be involved in the progress of epileptogenesis.
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Affiliation(s)
- Yu Wang
- Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China.
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Differential expressions of aquaporin subtypes in astroglia in the hippocampus of chronic epileptic rats. Neuroscience 2009; 163:781-9. [PMID: 19619613 DOI: 10.1016/j.neuroscience.2009.07.028] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Revised: 07/11/2009] [Accepted: 07/13/2009] [Indexed: 11/23/2022]
Abstract
In order to elucidate the roles of aquaporins (AQPs) in astroglial responses, we investigated AQP expressions in the experimental epileptic hippocampus. In control animals, AQP1 protein expression was restricted to the ventricular-facing surface of the choroid plexus. AQP4 was expressed in astrocyte foot processes near blood vessels and in ependymal and pial surfaces in contact with cerebrospinal fluid. AQP9 protein has been detected in cells lining the cerebral ventricles, and in astrocytes. Six to eight weeks after status epilepticus (SE), AQP1 expression was mainly, but not all, detected in vacuolized astrocytes, which were localized in the stratum radiatum of the CA1 region. AQP4 was negligible in vacuolized CA1 astrocytes, although AQP4 immunoreactivity in non-vacuolized astrocytes was increased as compared to control level. AQP9 expression was shown to be mainly induced in non-vacuolized CA1 astrocytes. Therefore, our findings suggest that AQP subunits may play differential roles in various astroglial responses (including astroglial swelling and astroglial loss) in the chronic epileptic hippocampus.
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