OBJECTIVETo study the role of neuronal nitric oxide synthase (nNOS) in aged rats' hippocampal delayed neuronal death (DND) following brain ischemia.

METHODSModels of incomplete brain ischemia were induced by clipping common carotid artery. A total of 46 aged SD rats were divided into 8 groups: normal control group (Group A, n=5), sham-operation group (Group B, n=5), reperfusion 1, 6, 12, 24, 48, and 96 hours groups after brain ischemia for 30 minutes (Group C, D, E, F, G, and H, n=6/group). The expression of nNOS was examined by immunohistochemistry and neuronal ultrastructural changes were observed by the transmission electron microscopy (TEM) at different time points after reperfusion.

RESULTSImmunohistochemistry showed that nNOS expression in the hippocampal neurons was high in Group E, low expression in Group D, moderate expression in Group F and G. There was nearly no expression of nNOS in Group A, B, C, and H. Ultrastructure of hippocampal neurons was damaged more severely in reperfusion over 24 hours groups.

CONCLUSIONSNitric oxide (NO) may be one of the important factors in inducing DND after ischemia/reperfusion.

Animals ; Apoptosis ; Brain Ischemia ; enzymology ; Female ; Hippocampus ; enzymology ; pathology ; Immunohistochemistry ; Male ; Microscopy, Electron ; Neurons ; enzymology ; Nitric Oxide Synthase ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; enzymology

OBJECTIVETo establish a simple, reproducible, and practical mechanical injury model of hippocampal neurons of Sprague-Dawley rats in vitro.

METHODSHippocampal neurons isolated from 1-2-day old rats were cultured in vitro. Mild, moderate and severe mechanical injuries were delivered to the neurons by syringe needle tearing, respectively. The control neurons were treated identically with the exception of trauma. Cell damage was assessed by measuring the Propidium Iodide (PI) uptaking at different time points (0.5, 1, 6, 12 and 24 hours) after injury. The concentration of neuron specific enolase was also measured at some time points.

RESULTSPathological examination showed that degeneration, degradation and necrosis occurred in the injured cultured neurons. Compared with the control group, the ratio of PI-positive cells in the injured groups increased significantly after 30 minutes of injury (P<0.05). More severe the damage was, more PI-positive neurons were detected. Compared with the control group, the concentration of neuron specific enolase in the injured culture increased significantly after 1 hour of injury (P<0.05).

CONCLUSIONSThe established model of hippocampal neuron injury in vitro can be repeated easily and can simulate the damage mechanism of traumatic brain injury, which can be used in the future research of traumatic brain injury.

Analysis of Variance ; Animals ; Brain Injuries ; enzymology ; pathology ; Equipment Design ; Hippocampus ; enzymology ; injuries ; In Vitro Techniques ; Neurons ; enzymology ; pathology ; Phosphopyruvate Hydratase ; biosynthesis ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reproducibility of Results

OBJECTIVE: To observe the expressions of sphingosine kinase 1 (SphK1) and sphingosine-1-phosphate receptor 2 (S1PR2) in hippocampus of epileptic rats and to investigate the pathogenesis of SphK1 and S1PR2 in epilepsy. METHODS: One hundred and eight male Sprague-Dawley (SD) rats were randomly divided into control group (n=48) and pilocarpine (PILO) group (n=60). A robust convulsive status epilepticus (SE) was induced in PILO group rats by the application of pilocarpine. Control group rats were injected with respective of physiological saline. Pilocarpine group was randomly divided into 6 subgroups (n=8): acute group (E6 h, E1 d, E3 d), latent group (E7 d) and chronic group (E30 d, E56 d). Each subgroup has 8 control rats and 8 epileptic rats. Hippocampal tissue and brain slices were obtained from control rats and rats subjected to the Li-PILO model of epilepsy at 6 h, 1 d, 3 d,7 d,30 d and 56 d after status epilepticus (SE). Western blot technique was used to determine the expressions of SphK1 and S1PR2 in hippocampus at different point of time after pilocarpine treatment. Immunofluorescence was applied to detect the activation and proliferation of hippocampal astrocytes and the localization of SphK1 and S1PR2 in rat hippocampal astrocytes. RESULTS: Compared with control group, the levels of SphK1 in acute phase (E3 d), latent phase (E7 d) and chronic phase (E30 d, E56 d) were significantly increased while the expressions of S1PR2 were decreased in acute phase (E3 d), latent phase (E7 d) and chronic phase (E30 d, E56 d)(P＜0.05 or P＜0.01). Immunofluorescence results showed astrocyte activation and proliferation in hippocampus of epileptic (E7 d) rats (P＜0.05). Confocal microscopy confirmed the preferential expressions of SphK1 and S1PR2 in epileptic rat(E7 d)hippocampal astrocytes. CONCLUSION The results indicate that SphK1 and S1PR2 may play an important role in the pathogenesis of epilepsy by regulating the activation and proliferation of hippocampal astrocytes and altering neuronal excitability.
Animals ; Astrocytes ; enzymology ; Epilepsy ; enzymology ; physiopathology ; Hippocampus ; cytology ; enzymology ; Male ; Phosphotransferases (Alcohol Group Acceptor) ; metabolism ; Pilocarpine ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Lysosphingolipid ; metabolism

OBJECTIVETo observe the influence of lead exposure on the activity of nitric oxide synthase (NOS) in different brain regions of rat.

METHODSBy establishing a series of rat models exposed to different low levels of lead (drinking water containing 0.025%, 0.050%, 0.075% of lead acetate) during developing period, NOS activities in hippocampus, cerebellum, cerebral cortex and brain stem were studied.

RESULTSOn the 21st day after birth, NOS activities in hippocampus of three levels of lead exposed groups [(1.53 +/- 0.20), (1.66 +/- 0.23), (1.88 +/- 0.32) U/mg pro respectively], and in cerebellum [(0.87 +/- 0.24), (0.85 +/- 0.09), (0.91 +/- 0.18) U/mg pro respectively] were significantly lower than those of control group [(2.36 +/- 0.18), (1.41 +/- 0.18) U/mg pro, respectively, P < 0.01]. NOS activities in cerebral cortex of 0.075% group [at 7, 14, 21 d of age [(1.29 +/- 0.14), (1.03 +/- 0.15), (0.69 +/- 0.10) U/mg pro] were significantly lower than those in control group [(2.54 +/- 0.31), (1.64 +/- 0.22), (1.24 +/- 0.14) U/mg pro respectively], and 0.025% group [(2.42 +/- 0.19), (1.59 +/- 0.17), (1.27 +/- 0.12) U/mg pro respectively], and 0.050% group [(2.56 +/- 0.53), (1.77 +/- 0.19), (1.24 +/- 0.10) U/mg pro respectively, P < 0.05]. There were no significant differences among control, 0.025%, and 0.050% groups (P > 0.05). Lead exposure had no influence on NOS activity in brain stem at the same age (P > 0.05).

CONCLUSIONNOS activities in hippocampus, cerebellum and cerebral cortex were inhibited by low level lead exposure and the degree of the effect was related to Pb exposure time and/or level of Pb exposed.

Animals ; Brain ; drug effects ; enzymology ; Brain Stem ; drug effects ; enzymology ; Cerebellum ; drug effects ; enzymology ; Cerebral Cortex ; drug effects ; enzymology ; Dose-Response Relationship, Drug ; Female ; Hippocampus ; drug effects ; enzymology ; Lead ; toxicity ; Nitric Oxide Synthase ; metabolism ; Rats ; Rats, Sprague-Dawley ; Time Factors

OBJECTIVETo explore action mechanism of acupuncture and moxibustion for Alzheimer's disease (AD) to provide evidence for prevention and treatment with acupuncture and moxibustion on AD in clinic.

METHODSEighty SPF-grade male Wistar rats, (200 +/- 20) g, were randomly divided into a normal group, a sham-operation group, a model group and a treatment group, 20 cases in each one. The model was duplicated with injection of Abeta1-42 in rats' hippocampus. Expect the treatment group, the rest groups were treated with regular feeding after respective intervention. The treatment group was treated with acupuncture and moxibustion at "Baihui" (GV 20) and "Shenshu" (BL 23), once a day, seven days as a treatment course and totally for two courses. There was one day of interval between the courses. The immunohistochemistry and quantitative RT-PCR methods were applied to test level of Abeta-binding alcohol dehydrogense (ABAD) and cytochrome oxidase IV (COX IV) in hippocampal neurons mitochondria.

RESULTSAcupuncture and moxibustion could reduce effectively level of ABAD and improve activity of COX IV in hippocampal neurons mitochondria in the treatment group, which has statistical significance compared with that in the model group (P < 0.01) and no statistical significance compared with that in the normal group and sham-operation group (P > 0.05). This indicated that acupuncture and moxibustion could effectively suppress overexpression of ABAD, improve activity of COX IV and reduce leak of reactive oxygen species, which could improve metabolic disturbance of mitochondria energy to achieve the goal of prevention and treatment of AD.

CONCLUSIONThe prevention and treatment of AD with acupuncture and moxibustion could be related with suppressing overexpression of ABAD and improving activity of COX IV in hippocampal neurons mitochondria to improve mitochondria energy metabolism.

3-Hydroxyacyl CoA Dehydrogenases ; genetics ; metabolism ; Acupuncture Therapy ; Alzheimer Disease ; enzymology ; metabolism ; therapy ; Animals ; Electron Transport Complex IV ; genetics ; metabolism ; Energy Metabolism ; Hippocampus ; cytology ; enzymology ; metabolism ; Humans ; Male ; Mitochondria ; enzymology ; metabolism ; Moxibustion ; Neurons ; enzymology ; metabolism ; Rats ; Rats, Wistar

Electroconvulsive shock (ECS) has been suggested to affect cAMP signaling pathways to exert therapeutic effects. ECS was recently reported to increase the expression of PDE4 isoforms in rat brain, however, these studies were limited to PDE4 family in the cerebral cortex and hippocampus. Thus, for comprehensive understanding of how ECS regulates PDE activity, the present study was performed to determine whether chronic ECS treatment induces differential changes in the expression of all the PDE isoforms in rat brains. We analyzed the mRNA expression of PDE isoforms in the rat hippocampus and striatum using reverse transcription polymerase chain reaction. We found chronic ECS treatment induced differential changes in the expression of PDE isoform 1, 2, 3, 4, 5 and 7 at the rat hippocampus and striatum. In the hippocampus, the expression of PDE1A/B (694%), PDE4A (158%), PDE4B (323 %), and PDE4D (181%) isoforms was increased from the controls, but the expression of PDE2 (62.8%) and PDE7 (37.8%) decreased by chronic ECS treatment. In the striatum, the expression of PDE1A/B (179%), PDE4A (223%), PDE4B (171%), and PDE4D (327%) was increased by chronic ECS treatment with the concomitant decrease in the expression of PDE2 (78.4%) and PDE3A (67.1%). In conclusion, chronic ECS treatment induces differential changes in the expression of most PDE isoforms including PDE1, PDE2, PDE3, PDE4, PDE5, and PDE7 in the rat hippocampus and striatum in an isoform- and brain region-specific manner. Such differential change is suggested to play an important role in regulation of the activity of PDE and cAMP system by ECS.
3',5'-Cyclic-Nucleotide Phosphodiesterase/analysis* ; Animal ; Corpus Striatum/enzymology* ; Electroconvulsive Therapy* ; Gene Expression Regulation, Enzymologic ; Hippocampus/enzymology* ; Isoenzymes/analysis* ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the effect of deltamethrin on the apoptotic rate and the expression of caspase-3 in rat neural cells.

METHODSMale Wistar rats were randomly divided into 5 groups: control, 5 h, 24 h, 48 h and 5 d exposed groups. Apoptotic rate and the expression of caspase-3 were measured by FACS420 Flow Cytometer; Ac-DEVD-pNa was used as a substrate to detect the activity of caspase-3.

RESULTSApoptotic rates in 24 h, 48 h and 5 d exposed groups in hippocampus and cerebral cortex [hippocampus: (8.45 +/- 1.02)%, (9.44 +/- 1.14)%, (7.58 +/- 0.75)%; cerebral cortex: (7.90 +/- 0.49)%, (8.01 +/- 0.87)%, (7.97 +/- 0.41)% respectively] were higher than those in the control [hippocampus: (2.97 +/- 0.36)%; cerebral cortex: (3.50 +/- 0.48)%] (P < 0.01); the activity of caspase-3 in 5 h, 24 h and 48 h exposed groups (A(405) nm in hippocampus: 0.389 +/- 0.038, 0.472 +/- 0.041, 0.295 +/- 0.049; A(405) nm in cerebral cortex: 0.321 +/- 0.068, 0.429 +/- 0.077, 0.344 +/- 0.047) and 5 d group of hippocampus (0.246 +/- 0.065) were all higher than those of the control (hippocampus: 0.184 +/- 0.054; cerebral cortex: 0.198 +/- 0.049) (P < 0.05, P < 0.01); the expression of caspase-3 in 5 h, 24 h and 48 h exposed groups increased apparently while 5 d group did not.

CONCLUSIONExposure to high dose of deltamethrin would affect the apoptosis, the activity and expression of caspase-3 in rat neural cells. The increase in caspase-3 activity and expression occurred before the rising of neuronal apoptotic rate may be the upstream event of apoptosis.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; Caspases ; metabolism ; Cerebral Cortex ; enzymology ; pathology ; Hippocampus ; enzymology ; pathology ; Insecticides ; pharmacology ; Male ; Nitriles ; pharmacology ; Pyrethrins ; pharmacology ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVETo explore the mechanism of electroacupuncture (EA) in the treatment of post-traumatic stress disorder (PTSD).

METHODSThirty male Sprague-Dawley rats were randomly divided into a normal group, a model group and an electroacupuncture group. The single prolonged stress (SPS) method was used to set up the PTSD models in latter two groups. After SPS Stimulation, EA group was treated with 2Hz electroacupuncture at Baihui (GV 20) and Zusanli (ST 36) for 30 min, once a day for a week. Reverse transcriptase polymerase chain reaction (RT-PCR) and immuno-histochemistry were used to detect the mRNA and protein expression of nNOS in the hippocampus of rats in the each group.

RESULTS(1) The nNOS mRNA expression in hippocampus in model group was higher than that in normal group (P < 0.05). But the expression in EA group was lower significantly than that in model group (P < 0.05). (2) The nNOS protein expression in hippocampus CA1 and CA3 in model group was higher than that in normal group (P < 0.05). But after electroacupuncture treatment, its expression in EA group was lower significantly than that in model group (P < 0.05). The nNOS protein expression in hippocampal CA2 had no difference among all three groups.

CONCLUSIONThe elevated nNOS expression in hippocampus may be involved in the pathological process of PTSD. Electroacupuncture play a down-regulation effects in the hippocampal nNOS expression, which may be one mechanism of electroacupuncture for treatment of PTSD.

Animals ; Electroacupuncture ; Hippocampus ; enzymology ; Humans ; Male ; Nitric Oxide Synthase Type I ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Stress Disorders, Post-Traumatic ; enzymology ; genetics ; therapy

OBJECTIVETo determine the spatio-temporal expression of p70S6k activation in hippocampus in mesial temporal lobe epilepsy.

METHODSTemporal lobe epilepsy model was established by stereotaxically unilateral and intrahippocampal injection of kainite acid (KA) in adult male C57BL/6 mice. Latent and chronic epileptogenesis were represented by mice 5 days after KA injection (n = 5) and mice 5 weeks after KA injection (n = 8), respectively. Control mice (n = 5) were injected with saline. Immunohistochemical assays were performed on brain sections of the mice.

RESULTSHippocampus both ipsilateral and contralateral to the KA injection displayed significantly up-regulated pS6 immunoreactivity in dispersed granule cells in 5-day and 5-week model mice.

CONCLUSIONThe activation of p70S6k is mainly located in the dentate gyrus in KA-induced mouse model of temporal lobe epilepsy, indicating that the activation may be related with the disperse degree and hypertrophy of granule cells.

Animals ; Epilepsy, Temporal Lobe ; enzymology ; Hippocampus ; enzymology ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred C57BL ; Phosphorylation ; Ribosomal Protein S6 Kinases, 70-kDa ; analysis ; metabolism

The changed process of bioenergy and the effects of electrode interfering on penicillin-induced epileptic brains in epileptic seizures rats were investigated. Fifty Sprague-Dawley (SD) rats were randomly divided into 4 groups, i. e. normal saline control group (group A), penicillin model group (group B), metal electrode interfere group (group C) and insulated electrode interfere group (group D). The epileptogenic potential and the expressions of the beta subunit of-ATP synthase( ATP5B) in hippocampal neurons were measured. The epileptogenic foucus potential and expressions of ATP5B in hippocampus neurons showed that the trend increased at first and decreased implantation of later, and the implantation of metal electrodes decreased the epileptogenic foucus potential at corresponding time point, but had no effect on the expressions of ATP5B. The change of epileptogenic focus potential was reduced by implantation of metal electrode, possibly due to the alteration of corrosponding bioenergy metabolism which had participated in the process of epileptic seizure.
Animals ; Electrodes ; Energy Metabolism ; Epilepsy ; chemically induced ; enzymology ; physiopathology ; Hippocampus ; enzymology ; Male ; Mitochondrial Proton-Translocating ATPases ; genetics ; metabolism ; Penicillins ; Rats ; Rats, Sprague-Dawley