[Vasovagal syncope or postural orthostatic tachycardia syndrome in children with neurological symptoms at disease onset: a clinical analysis of 88 cases].

OBJECTIVE: To study the clinical features of vasovagal syncope (VVS) and postural orthostatic tachycardia syndrome (POTS) in children with neurological symptoms at disease onset. METHODS: A retrospective analysis was performed on the medical data of 88 children with the initial symptoms of the nervous system, such as transient loss of consciousness, dizziness, headache, and convulsion, who were finally diagnosed with VVS or POTS. RESULTS: Of the 88 children, there were 35 boys (40%) and 53 girls (60%), with an age of 4-15 years. The peak age of onset was between 10 and 13 years. All the children had the initial symptoms of transient loss of consciousness, dizziness, headache, and convulsion. Nervous system diseases were excluded by electroencephalography, cerebrospinal fluid examination, and cranial MRI. Of the 88 children, 53 (60%) were confirmed with VVS, and 35 (40%) with POTS, according to the results of head-up tilt test (HUTT). Five children with the initial symptom of transient loss of consciousness were misdiagnosed with epilepsy. Predisposing factors were determined for 59 children (67%), and prolonged standing was the most common factor, followed by change in body position and strenuous exercise. Premonitory symptoms were observed in 66 children (75%), among which chest discomfort was the most common symptom, followed by gastrointestinal symptoms (nausea, vomiting, and abdominal pain) and pale complexion. All 88 children received health education and exercise for autonomic nerve function, among whom 53 children with VVS were given oral rehydration salts and 35 children with POTS were given oral rehydration salts and metoprolol. All 88 children were followed up for 18 months, and the response rates to the above treatment at 3, 6, 12, and 18 months of follow-up were 87%, 93%, 93%, and 90% respectively. CONCLUSIONS: In addition to nervous system diseases, functional cardiovascular diseases including VVS and POTS should be considered for children with the initial symptoms of transient loss of consciousness, dizziness, headache, and convulsion. HUTT can be used to make a confirmed diagnosis, and the early treatment can achieve a good outcome.

Novel NtA and LG1 Mutations in Agrin in a Single Patient Causes Congenital Myasthenic Syndrome.

Congenital myasthenic syndrome (CMS) is a group of genetic disorders of neuromuscular transmission that is characterized by muscle weakness. A mutation in the gene encoding agrin (AGRN) is a rare cause of CMS, and only a few families or isolated cases have been reported. We reported a pediatric proband exhibiting muscle weakness in the trunk and limbs with skeletal malformation and intellectual disability and performed whole-exome sequencing (WES) of the proband parent-offspring trio. Results revealed a new compound heterozygous mutation in AGRN: c.125A>C (p.Glu42Ala) in the N-terminal agrin domain (NtA) and c.4516G>A (p.Ala1506Thr) in the laminin G1 domain (LG1). Bioinformatic analysis predicted the mutation as possibly pathogenic. The new compound heterozygous mutation in AGRN may disrupt agrin's known function of bridging laminin and α-dystroglycan and undermine the formation and maintenance of the neuromuscular junction (NMJ) via both muscular and neural agrin pathways. It may also induce secondary peripheral neuropathy and skeletal malformation.

Clinical characteristics of anti-N-methyl-D-aspartate receptor encephalitis in children. / 儿童抗N-甲基-D-å¤©å†¬æ°¨é ¸å—ä½“è„‘ç‚Žçš„ä¸´åºŠç‰¹å¾.

OBJECTIVES: To analyze the clinical characteristics and prognosis of children with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and to provide a basis for early clinical identification of this disease. METHODS: The clinical data of 42 cases of anti-NMDAR encephalitis at Department of Pediatrics, Second Xiangya Hospital, Central South University from January 2015 to March 2018 were collected. The clinical features and followed-up outcomes were analyzed retrospectively. RESULTS: There were 15 cases (35.7%) of males and 27 cases (64.3%) of females in 42 children, with a ratio of 1꞉1.8. They were aged from 4 months to 17 years, with an average of (9.20±4.66) years. The most common initial symptoms were seizures (47.6%, 20/42) and mental behavior disorder (35.7%, 15/42). During the course of the disease, 85.7% patients(36/42) had mental and behavior disorder, 85.7% patients (36/42) had epilepsy, 76.2% (32/42) had speech disorder, 66.7% patients (28/42) had dyskinesia, 66.7% patients (28/42) had the decreased level of consciousness, 61.9% patients (26/42) had autonomic instability, and 57.1% (24/42) patients had sleep disorder. All the children had positive antibody against NMDA receptor resistance encephalitis in cerebrospinal fluid. Head MRI showed the abnormal incidence was 50.0% (21/42), and the lesions involved in parietal lobe, frontal lobe, temporal lobe, occipital lobe, midbrain, thalamus, basal ganglia and optic nerve. There was a patient with optic nerve damage combined with myelin oligodendrocyte glycoprotein (MOG) antibody positive. Forty cases were examined by electroencephalogram (EEG), 92.5% cases (37/40) were abnormal, mainly showing diffuse slow waves, and δ brushes could be seen in severe cases. And there was 1 patient (2.4%) complicated with mesenteric teratoma. The mRS score (2.14±1.46) at discharge was significantly lower than the highest mRS score (3.88±1.38) during hospitalization (P<0.05). After 3-39 months of follow-up, mRS score at 3 months after discharge was only 0.81±1.29, which was still improved compared with that at discharge, 76.2% cases (32/42) experienced complete or near-complete recovery (mRS score≤2), and 4.8% (2/42) cases relapsed. There was no mortality; the initial time of immunotherapy and the highest mRS score in the course of the disease were the factors affecting the prognosis. The earlier the starting time for immunotherapy and the lower mRS score in the course of the disease were, the better the prognosis was. CONCLUSIONS: Seizures, mental and behavior disorder, dyskinesias, speech disorder and autonomic instability are common clinical manifestations of anti-NMDAR encephalitis in children. The effect of immunotherapy is significant, and the time to start immunotherapy and the severity of the disease are important factors affecting the prognosis. Anti-NMDAR encephalitis can be combined with other autoantibodies, but its clinical significance and mechanism need further study.

Clinicopathological characteristics of dysplastic teratomous neuroglia with anti-N-methyl-d-aspartate receptor encephalitis.

In this study, we investigated whether unique pathological characteristics exist in teratomas that can trigger autoimmune anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. We compared a case of retroperitoneal teratoma associated with anti-NMDAR encephalitis and four control cases. The encephalitis-positive case showed that (i) more dysplastic neuroglia with higher Ki-67 labeling index values than the control cases, which met the diagnostic criteria of astrocytoma, (ii) the NMDAR subunit NR1 was expressed more abundantly in neuroglial tissue where many neuroglial cells co-expressed glial fibrillary acidic protein (GFAP) and NR1 and formed abnormally large cellular masses, (iii) intense NR1 expression occurs in squamous epithelium near neuroglial tissue and lymphocyte infiltration. This study showed that dysplastic neuroglial tissue resembling central nervous system tumors, which might promote autoimmunity, distinguished the case with NMDAR encephalitis from the controls. Additionally, abnormal expression of NR1 occurs in non-neural tissues and could be triggered by inflammation and participate in autoimmunity.

A rare case of pediatric moyamoya disease with reversible white matter lesions in a 3-year-old Chinese girl.

Moyamoya disease is a chronic cerebral vascular disease characterized by progressive occlusion of the cerebral arteries and resulting in the development of abnormal collateral circulation. We report a case of moyamoya disease in a 3-year-old Chinese girl with partly reversible white matter lesions. This case indicates that, in pediatric moyamoya disease, white matter lesions may be associated with cerebral ischemia, and they may be reversible after treatment.

Early-onset epileptic encephalopathy with de novo SCN8A mutation.

Early-onset epileptic encephalopathies (EOEEs) are clinically and genetically heterogeneous disorders characterized by intractable seizures and unremitting interictal paroxysmal epileptiform activity. Consequently, these syndromes impair neurodevelopment during the first year of life. Currently, the etiology of these disorders is largely unknown. In this study, Childhood-Onset Epilepsy Gene Panel Testing (containing 511 epilepsy-related genes) was performed in a parent-offspring trio. In this family, the son had refractory seizures, intellectual disability, and motor abnormalities, and he was diagnosed with EOEE. The boy later died from a sudden unexpected death in epilepsy (SUDEP) at the age of 26 months. In this case, we identified a de novo mutation (c.4423G > A; glycine [Gly]1475 arginine [Arg]) classified as heterozygous missense located in the inactivation gate section of the SCN8A (voltage-gated sodium-channel type VIII alpha subunit) gene. This result strengthens the association between the SCN8A gene and EOEE, and more attention should be given to its high rate of SUDEP. Further studies to determine the pathogenic mechanisms of SCN8A mutations should be warranted at the inactivation gate section of this sodium channel in both neurons and cardiac muscles.

Alpha7 nicotinic acetylcholine receptor is required for amyloid pathology in brain endothelial cells induced by Glycoprotein 120, methamphetamine and nicotine.

One of the most challenging issues in HIV-associated neurocognitive disorders (HAND) caused by HIV-1 virotoxins and drug abuse is the lack of understanding the underlying mechanisms that are commonly associated with disorders of the blood-brain barrier (BBB), which mainly consists of brain microvascular endothelial cells (BMEC). Here, we hypothesized that Glycoprotein 120 (gp120), methamphetamine (METH) and nicotine (NT) can enhance amyloid-beta (Aß) accumulation in BMEC through Alpha7 nicotinic acetylcholine receptor (α7 nAChR). Both in vitro (human BMEC) (HBMEC) and in vivo (mice) models of BBB were used to dissect the role of α7 nAChR in up-regulation of Aß induced by gp120, METH and NT. Aß release from and transport across HBMEC were significantly increased by these factors. Methyllycaconitine (MLA), an antagonist of α7 nAChR, could efficiently block these pathogenic effects. Furthermore, our animal data showed that these factors could significantly increase the levels of Aß, Tau and Ubiquitin C-Terminal Hydrolase L1 (UCHL1) in mouse cerebrospinal fluid (CSF) and Aß in the mouse brains. These pathogenicities were significantly reduced by MLA, suggesting that α7 nAChR may play an important role in neuropathology caused by gp120, METH and NT, which are the major pathogenic factors contributing to the pathogenesis of HAND.

MicroRNA-34b mediates hippocampal astrocyte apoptosis in a rat model of recurrent seizures.

BACKGROUND: Recurrent convulsions can cause irreversible astrocyte death, impede neuron regeneration, and further aggravate brain damage. MicroRNAs have been revealed as players in the progression of numerous diseases including cancer and Alzheimer's disease. Particularly, microRNA has been found linked to seizure-induced neuronal death. In this study, a rat model of recurrent convulsions induced by flurothyl treatments was utilised to assess the alterations of microRNA expressions in hippocampus tissues. We also applied an in vitro model in which primary astrocytes were exposed to kainic acid to verify the targets of miR-34b-5p identified in the animal model. RESULTS: We discovered that miR-34b-5p, a member of the miR-34 family, increased significantly in flurothyl-treated rat hippocampus tissue. More surprisingly, this upregulation occurred concurrently with accumulating astrocyte apoptosis, indicating the involvement of miR-34b-5p in seizures caused astrocyte apoptosis. Results from the in vitro experiments further demonstrated that miR-34b-5p directly targeted Bcl-2 mRNA, translationally repressed Bcl-2 protein, and thus modulated cell apoptosis by influencing Bcl-2, Bax, and Caspase-3. CONCLUSION: Our findings prove microRNAs play a role in mediating recurrent convulsions-induced astrocyte death and further indicate that miR-34b-5p could acts as a regulator for astrocyte apoptosis induced by recurrent seizures.

Histone deacetylase inhibitor SAHA attenuates post-seizure hippocampal microglia TLR4/MYD88 signaling and inhibits TLR4 gene expression via histone acetylation.

BACKGROUND: Epilepsy is a common neurological disorder characterized by recurrent unprovoked seizures. Seizure-induced TLR4/MYD88 signaling plays a critical role in activating microglia and triggering neuron apoptosis. SAHA is a histone deacetylase inhibitor that regulates gene expression by increasing chromatin histone acetylation. In this study, we investigated the role of SAHA in TLR4/MYD88 signaling in a rat seizure model. RESULTS: Sprague-Dawley rats with kainic acid (KA)-induced seizures were treated with SAHA. The expression of TLR4, MYD88, NF-κB P65 and IL-1ß in hippocampus was detected at hour 2 and 6 and day 1, 2, and 3 post seizure. SAHA pretreatment increased seizure latency and decreased seizure scores. The expression levels of TLR4, MYD88, NF-κB and IL-1ß increased significantly in both activated microglia and apoptotic neurons after KA treatment. The effects were attenuated by SAHA. Chromatin immunoprecipitation assays indicated that the H3 histone acetylation levels significantly decreased while H3K9 levels significantly increased in the KA treatment group. The H3 and H3K9 acetylation levels returned to control levels after SAHA (50 mg/kg) pretreatment. There was a positive correlation between the expression of TLR4 and the acetylation levels of H3K9. CONCLUSIONS: Histone deacetylase inhibitor SAHA can suppress seizure-induced TLR4/MYD88 signaling and inhibit TLR4 gene expression through histone acetylation regulation. This suggests that SAHA may protect against seizure-induced brain damage.

Research Progress on the Role of ABC Transporters in the Drug Resistance Mechanism of Intractable Epilepsy.

The pathogenesis of intractable epilepsy is not fully clear. In recent years, both animal and clinical trials have shown that the expression of ATP-binding cassette (ABC) transporters is increased in patients with intractable epilepsy; additionally, epileptic seizures can lead to an increase in the number of sites that express ABC transporters. These findings suggest that ABC transporters play an important role in the drug resistance mechanism of epilepsy. ABC transporters can perform the funcions of a drug efflux pump, which can reduce the effective drug concentration at epilepsy lesions by reducing the permeability of the blood brain barrier to antiepileptic drugs, thus causing resistance to antiepileptic drugs. Given the important role of ABC transporters in refractory epilepsy drug resistance, antiepileptic drugs that are not substrates of ABC transporters were used to obtain ABC transporter inhibitors with strong specificity, high safety, and few side effects, making them suitable for long-term use; therefore, these drugs can be used for future clinical treatment of intractable epilepsy.

Puerarin Suppress Apoptosis of Human Osteoblasts via ERK Signaling Pathway.

Puerarin, the main isoflavone glycoside extracted from Radix Puerariae, is an isoflavone traditional Chinese herb. Previous studies have demonstrated that puerarin could regulate osteoblast proliferation and differentiation to promote bone formation. However, the effect of puerarin on the process of human osteoblasts (hOBs) apoptosis is still unclear. In this study, we detected the function of puerarin on serum-free-induced cell apoptosis using ELISA and TUNEL arrays and then found that the mortality of hOBs was significantly decreased after exposure to 10(-10)-10(-6) M puerarin and reached the maximal antiapoptotic effect at the concentration of 10(-8) M. In addition, compared with the control group, puerarin notably increased the Bcl-2 protein levels while it decreased the Bax protein levels in the hOBs in a dose-dependent way. 10(-7) M puerarin decreased the Bax/Bcl-2 ratio with a maximal decrease to 0.08. Moreover, puerarin activated ERK signaling pathways in hOBs, and the antiapoptotic effect induced by puerarin was abolished by incubation of ERK inhibitor PD98059. Similarly, the estrogen receptor antagonist ICI182780 also suppressed the inhibitory effect of puerarin on hOBs apoptosis. In conclusion, puerarin could prevent hOBs apoptosis via ERK signaling pathway, which might be effective in providing protection against bone loss and bone remolding associated with osteoporosis.

MiR-133a modulates osteogenic differentiation of vascular smooth muscle cells.

Arterial calcification is a key pathologic component of vascular diseases such as atherosclerosis, coronary artery disease, and peripheral vascular disease. A hallmark of this pathological process is the phenotypic transition of vascular smooth muscle cells (VSMCs) to osteoblast-like cells. Several studies have demonstrated that microRNAs (miRNAs) regulate osteoblast differentiation, but it is unclear whether miRNAs also regulate VSMC-mediated arterial calcification. In the present study, we sought to characterize the role of miR-133a in regulating VSMC-mediated arterial calcification. Northern blotting analysis of VSMCs treated with ß-glycerophosphate demonstrated that miR-133a was significantly decreased during osteogenic differentiation. Overexpression of miR-133a inhibited VSMC transdifferentiation into osteoblast-like cells as evidenced by a decrease in alkaline phosphatase activity, osteocalcin secretion, Runx2 expression, and mineralized nodule formation. Conversely, the knockdown of miR-133a using an miR-133a inhibitor promoted osteogenic differentiation of VSMCs by increasing alkaline phosphatase activity, osteocalcin secretion, and Runx2 expression. Runx2 was identified as a direct target of miR-133a by a cotransfection experiment in VSMCs with luciferase reporter plasmids containing wild-type or mutant 3'-untranslated region sequences of Runx2. Furthermore, the pro-osteogenic effects of miR-133a inhibitor were abrogated in Runx2-knockdown cells, and the inhibition of osteogenic differentiation by pre-miR-133a was reversed by overexpression of Runx2, providing functional evidence that the effects of miR-133a in osteogenic differentiation were mediated by targeting Runx2. These results demonstrate that miR-133a is a key negative regulator of the osteogenic differentiation of VSMCs.

MicroRNA-204 regulates vascular smooth muscle cell calcification in vitro and in vivo.

AIMS: Medial artery calcification is a common macroangiopathy that initiates from a cell-regulated process similar to osteogenesis. Although the mechanisms governing this process remain unclear, epigenomic regulation by specific microRNAs might play a role in vascular smooth muscle cell (VSMC) calcification. In this study, we aimed to investigate whether miR-204 participates in the regulation of VSMC calcification. METHODS AND RESULTS: We found that miR-204 was suppressed in mouse aortic VSMCs during ß-glycerophosphate-induced calcification, whereas Runx2 protein levels were elevated. Overexpression of miR-204 by transfection of miR-204 mimics decreased Runx2 protein levels and alleviated ß-glycerophosphate-induced osteoblastic differentiation of VSMCs, whereas miR-204 inhibition by transfection of miR-204 inhibitors significantly elevated Runx2 protein levels and enhanced osteoblastic differentiation of VSMCs, suggesting the role of miR-204 as an endogenous attenuator of Runx2 in VSMC calcification. Luciferase reporter assays revealed Runx2 as the direct target of miR-204 by overexpression of miR-204 on the wild-type or mutant 3'-UTR sequences of Runx2 in VSMCs. In vivo overexpression of miR-204 by injection of miR-204 agomirs in Kunming mice attenuated vitamin D3-induced medial artery calcification. CONCLUSION: Our study has shown that down-regulation of miR-204 may contribute to ß-glycerophosphate-induced VSMC calcification through regulating Runx2. miR-204 represents an important new regulator of VSMC calcification and a potential therapeutic target in medial artery calcification.

[Investigation on the behavior problems of children aged 3 to 5 years in Changsha and comparison of the norm of Conners Parent Symptom Questionnaire in Chinese and American urban children].

OBJECTIVE: To investigate the behavior problems of children aged 3 to 5 years in Changsha and to compare the differences of the results detected by the norm of Conners Parent Symptom Questionnaire (PSQ) in Chinese and American urban children. METHODS: A total of 854 children aged 3 to 5 years were randomly sampled from 5 districts in Changsha City and their parents completed the Conners PSQ. RESULTS: The assessment by the norm of PSQ in American urban children demonstrated that the average prevalence of behavior problems was 20.4%, with 28.1% for boys and 12.4% for girls. There were significant differences between boys and girls (P<0.01). The factor score of anxiety in girls was markedly higher than that in boys (P<0.01). Learning and psychosomatic problems were the main problems in the children. The prevalences of conduct problems and impulse-restlessness, and abnormal restlessness index detected by the norm of PSQ in Chinese urban children were higher than those detected by the American norm. The prevalences of conduct problems and psychosomatic problems in boys by the norm of PSQ in Chinese urban children were significantly lower than those detected by the American norm, while the total prevalence of behavior problems was higher than that detected by American norm. There was a poor consistency in the assessment results of most factors of the PSQ and the total prevalence of behavior problems detected by the Chinese and American norms (KappP<0.4). CONCLUSIONS: The prevalence of behavior problems especially learning problems and psychosomatic problems in children aged 3 to 5 years is higher in Changsha. The consistency of assessment results is poor between the norms of China and America. It is recommended to use the China norm of PSQ in Chinese children aged 3 to 5 years because the Chinese norm is in line with China's national conditions and cultural background.

Apelin suppresses apoptosis of human vascular smooth muscle cells via APJ/PI3-K/Akt signaling pathways.

Apoptosis of vascular smooth muscle cells (VSMCs) plays an important role in regulating vascular remodeling during cardiovascular diseases. Apelin is the endogenous ligand for the G-protein-coupled receptor APJ and plays an important role in the cardiovascular system. However, the mechanisms of apelin on apoptosis of VSMCs have not been elucidated. Using a culture of human VSMCs as a model for the study of apoptosis, the relationship between apelin and apoptosis of human VSMCs and the signal pathway involved were investigated. Using western blotting, we confirmed that VSMCs could express APJ. To evaluate the possible role of apelin in VSMC apoptosis, we assessed its effect on apoptosis of human VSMCs. The results showed that apelin inhibited human VSMCs apoptosis induced by serum deprivation. Suppression of APJ with small-interfering RNA (siRNA) abolished the anti-apoptotic activity of apelin. Apelin increased Bcl-2 protein expression, but decreased Bax protein expression. An increase in activation of extracellular signal-regulated protein kinase (ERK) and Akt (a downstream effector of phosphatidylinositol 3-kinase) was shown after apelin stimulation. Suppression of APJ with siRNA abolished the apelin-induced activation of ERK and Akt. LY294002 (a PI3-K inhibitor) blocked apelin-induced activation of Akt and abolished the apelin-induced antiapoptotic activity. Our study suggests that apelin suppresses serum deprivation-induced apoptosis of human VSMCs, and that the anti-apoptotic action is mediated through the APJ/PI3-K/Akt signaling pathways.

[Effect of magnesium-free on glucocorticoid receptor expression in primary cultured cortical neurons of fetal rats in vitro].

OBJECTIVE: To study the changes of glucocorticoid receptor (GR) expression in embryonic rat cortical neurons exposed to transient Mg(2+)-free treatment. METHODS: Six days after rat cortical neuronal cultures, two groups were created based on the medium to which were transiently exposed. The control group was exposed to a physiological solution (PS), and the Mg(2+)-free group was exposed to the same medium as the control group except for the removal of magnesium. The expression of GR mRNA and protein was determined by real-time PCR and immunocytochemistry staining 1, 7 and 12 days after transient Mg(2+)-free treatment. RESULTS: Compared to the control group, the Mg(2+)-free group displayed the significantly less accumulated optical density (AOD) of GR immunoreactivity 12 days after transient Mg(2+)-free treatment (p<0.05). On the contrary, GR mRNA expression increased significantly 1 and 7 days after transient Mg(2+)-free treatment in the Mg(2+)-free group (p<0.05). CONCLUSIONS: GR expression is modified following Mg-free-induced injury in cultured developing neurons in rats.

[Effects of neonatal recurrent seizures on glucocorticoid receptor expression in the rat brain].

OBJECTIVE: To investigate the effets of flurothyl-induced neonatal recurrent seizures on glucocorticoid receptor (GR) expression in the rat brain. METHODS: Forty-eight seven-day-old Sprague-Dawley rats were randomly divided into two groups: control and seizure. Seizures were induced by inhalant flurothyl daily for six consecutive days. Brains were sampled on postnatal days 13, 15 and 19. The expression of GR protein in the cerebral cortex was detected by Western blot and immunohistochemical method. RESULTS: The expression of GR in the cerebral cortical plasma protein was significantly lower in the seizure group than in the control group on postnatal day 15. The expression of GR protein in the cerebral cortical nuclear protein decreased significantly in the seizure group compared with that in the control group on postnatal days 15 and 19 (p<0.05). Compared to the control group, the accumulated optical density (AOD) of GR immunoreactivity (IR) decreased significantly in the parietal cortex on postnatal day 13 (p<0.05), the AOD of GR IR decreased significantly in the parietal cortex and the temporal cortex on postnatal day 15 (p<0.05), and the AOD of GR IR decreased significantly in the parietal cortex, temporal cortex and the frontal cortex in the seizure group on postnatal day 19 (p<0.05). CONCLUSIONS: Recurrent seizures in neonatal rats result in abnormal GR expression in the cerebral cortex which might play an important role in short-term brain injury induced by early recurrent seizures.

[Short-term effects of recurrent neonatal seizures on gamma-aminobutyric acid A receptor alpha1 and beta2 subunit expression in the rat brain].

OBJECTIVE: To investigate the short-term effects of flurothyl-induced neonatal recurrent seizures on gamma-aminobutyric acid A receptor (GABAAR) alpha1 and beta2 subunit expression in the rat brain, and to study the relationship between the alterations of GABAAR subunits in the developing brain and seizure-induced brain injury. METHODS: Sixty-four 7-day-old Sprague-Dawley rats were randomly divided into two groups: control and seizure. Seizures were induced by inhalant flurothyl daily for six consecutive days. The expression of GABAAR alpha1 and beta2 subunits protein in the cerebral cortex and the hippocampus were detected by Western blot and immunohistochemistry method 1 and 7 days after recurrent seizures. RESULTS: Compared to the control, the accumulated optical density (AOD) of GABAAR alpha1 subunit immunoreactivity (IR) in the parietal cortex, the CA3-CA4 regions and the dentate gyrus in seizure rats increased significantly 1 day after recurrent seizures (P<0.05). The AOD of GABAAR alpha1 subunit IR in the parietal cortex, the CA1-CA4 regions and the dentate gyrus in seizure rats increased significantly 7 days after recurrent seizures compared with the control (P<0.05). The expression of GABAAR alpha1 subunit in the hippicampus and the cerebral cortex increased significantly in seizure rats compared with that in control rats 1 and 7 days after recurrent seizures. After 7 days of recurrent seizures, the AOD of GABAAR beta2 subunit IR in the CA1-CA2 regions increased significantly in the seizure group compared with that in the control group (P<0.05), but the AOD of GABAAR beta2 subunit IR in the thalamus decreased significantly in the seizure group compared with that in the control group (P<0.05). The expression of GABAAR beta2 subunit protein in the hippocampus increased significantly in the seizure group compared with that in the control group 7 days after recurrent seizures (P<0.05). CONCLUSIONS: Recurrent neonatal seizures may result in the short-term alterations of GABAAR alpha1 and beta2 subunits expression in the cerebral cortex and the hippocampus in rats, suggesting the alterations of GABAAR subunit expression may be related to the developing brain injury following recurrent seizures.

[Long-term effects of recurrent seizures in neonate period on gamma-aminobutyric acid A receptor alpha1 and beta2 subunits expression in adult brain: experiment with rats].

OBJECTIVE: To investigate the long-term effects of recurrent seizures in neonate period on the expression of gamma-aminobutyric acid A receptor (GABAAR) alpha1 and beta2 subunits in brain and spatial memory and seizure susceptibility in adult period. METHODS: Thirty-two 7-day-old SD rats were randomly divided into 2 equal groups: seizure group, inhaling flurothyl to induce seizure daily for 6 days, and control group. On days 61 - 65 after birth Morris water maze test was used to record the escape latency. On day 75 after birth pentylenetetrazol (PTZ) was injected intraperitoneally to induce seizure so as to record the latency. Then the rats were killed to take their brains, 8 in each group used to undergo immunohistochemistry to examine the protein expression of the GABAAR alpha1 and beta2 subunits, and the other 8 in each group used to examine the mRNA expression of the GABAAR alpha1 and beta2 subunits in the brains using RT-PCR. RESULTS: On day 64 the escape latency of the seizure group was 82,424 ms +/- 35,622 ms, significantly longer than that of the control group (40,712 ms +/- 29,468 ms, P = 0.001). On day 75 the frequency of crossing target within 120 s in the water maze of the seizure group was 1.2 times +/- 0.9 times, significantly less than that of the control group (3.1 times +/- 1.3 times, P < 0.01). The seizure latency after the PTZ injection of the seizure group was (1487 +/- 662) s, not significantly different from that of the control group (1841 s +/- 648 s, P = 0.133). In comparison with the control group the accumulated optical density (AOD) of GABAAR alpha1 subunit protein immunoactivity in the parietal cortex, and hippocampal CA1-2 and CA4 regions of the seizure group decreased significantly (all P < 0.05), and was not significantly different in the frontal cortex, dentate gyrus, and hippocampal CA3 region (all P > 0.05). In comparison with the control group the accumulated optical density (AOD) of GABAAR beta2 subunit protein immunoactivity in the thalamus, and hippocampal CA1-4 regions of the seizure group decreased significantly (all P < 0.05), and was not significantly different in the frontal cortex and parietal cortex (both P > 0.05). In comparison with the control group the mRNA expression of GABAAR alpha1 subunit and the mRNA expression of GABAAR beta2 subunit of the seizure group were significantly lower in the hippocampus (both P < 0.05) and not significantly different in the cerebral cortex (both P > 0.05). CONCLUSION: Recurrent seizures in neonate period modify the expression of GABAAR alpha1 and beta2 subunits in the cerebral cortex and hippocampus in adult period which may be related to cognitive deficit.