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 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

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

To explore the mechanism of interleukin-1beta (IL-1beta) in the onset of seizure and the effect of IL-1beta on the expression of adenylyl cyclase (AC) in rats with seizure induced by L-glutamate. Experimental rats were first injected with IL-1beta and then L-glutamate (a dose under the threshold) was injected into the right lateral ventricle. The rats were sacrificed 4 h after the onset of epileptic activity and examined for changes in behavior, immunohistochemistry and compared with those with seizure induced by L-glutamate alone. It was found that the expression of AC in hippocampal and neocortex of rats with seizure induced by IL-1beta and L-glutamate were stronger than that of control group (P<0.05), without significant difference found between the L-glutamate group and IL-1beta plus L-glutamate group in the expression of AC, the latent period and the severity of seizure. When IL-ra were given (i.c.v.) first, there was no epileptic activity and the expression of AC did not increase. There were no differences in the expression of AC of rats with IL-1ra and that of control rats. But when 2-methyl-2-(carboxycyclopropyl) glycine (MCCG) was given (i.c.v.) first, the strongest expression of AC, the shortest latent period and the the most serious seizure activities were observed. The results indicated that IL-1beta could facilitate the onset of epilepsy induced by L-glutamate through IL-1R, metabotropic glutamate receptors might work with IL-1R and the increased expression of AC might be involved in the process.
Adenylyl Cyclases ; biosynthesis ; genetics ; Animals ; Glutamic Acid ; Hippocampus ; metabolism ; Interleukin-1 ; pharmacology ; Male ; Neocortex ; metabolism ; Rats ; Seizures ; chemically induced ; enzymology

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

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

OBJECTIVETo study the effects of 1-bromopropane (1-BP) on the functions of learning-memory and the central cholinergic system in rats.

METHODSForty male Wistar rats were randomly divided into four groups: low 1-BP group (200 mg/kg), middle 1-BP group (400 mg/kg), high 1-BP group (800 mg/kg) and control group, and the exposure time was 7 days. The Morris water maze (MWM) test was applied to evaluate the learning-memory function in rats. After the MWM test, the rats were sacrificed, the cerebral cortex and hippocampus were quickly dissected and homogenized in ice bath. The activity of acetylcholine esterase (AChE) and choline acetyltransferase (ChAT) in supernatant of homogenate were detected.

RESULTSThe latency and swim path-length of rats in middle and high 1-BP groups prolonged significantly in place navigation test and the efficiency of searching strategy obviously decreased, as compared with control group (P < 0.05 or P < 0.01). In spatial probe test, the number of crossing platform in three 1-BP groups decreased significantly, as compared with control group (P < 0.05 or P < 0.01). The cortical AChE activity of rats in middle and high 1-BP groups was significantly higher than that of control and low 1-BP group (P < 0.05 or P < 0.01). The AChE activity in rat hippocampus of high 1-BP group obviously increased, as compared with control group as compared with control group (P < 0.05). There was no significant difference of cortical ChAT activity between three 1-BP groups and control group (P > 0.05). In the hippocampus, there was no difference of ChAT activity among the groups (P > 0.05).

CONCLUSION1-BP exposure could significantly influence the learning-memory function in rats due to the increase of AChE activity.

Acetylcholinesterase ; metabolism ; Animals ; Cerebral Cortex ; drug effects ; enzymology ; Choline O-Acetyltransferase ; metabolism ; Hippocampus ; drug effects ; enzymology ; Hydrocarbons, Brominated ; toxicity ; Male ; Maze Learning ; drug effects ; Rats ; Rats, Wistar

OBJECTIVETo evaluate the effects of paroxetine on protein kinase PKA, PKC and CaMKII activities in different brain regions in a rat model of depression.

METHODSThirty-six adult male SD rats were randomized into 6 groups, including one control group (I) and 5 groups of depression model established by forcing the rats to swim for 4 weeks. The 5 depression groups received no treatment (II) or were treated with paroxetine at a single dose (III), for a week (IV), 2 weeks (V) or 4 weeks (VI). The radioactivity of PKA, PKC and CaMKII in the hippocampus and prefrontal cortex was quantitatively measured using a liquid scintillation counter.

RESULTSIn the rat hippocampus, PKA and CaMKII activities were significantly lower in groups II, III, IV, and V than in groups I and VI (P<0.01 or P<0.05), but comparable between groups VI and I (P>0.05). PKC activity was significantly lower in group II than in group I (P<0.01), but showed no significant difference between the paroxetine-treated groups and group I (P>0.05). In the prefrontal cortex, the activity of PKA in groups I, II, III, and IV was similar (P>0.05), but all significantly lower than that in groups V and VI (P<0.01). PKC activity was significantly higher in groups II and III than that in group I and other paroxetine-treated groups (P<0.01), and similar between groups IV and I (P>0.05); groups V and VI had significantly lower PKC activity than group I (P<0.01). Group I had the highest CaMKII activity among the groups (P<0.01).

CONCLUSIONChronic administration of paroxetine can reverse chronic stress-induced inhibition of PKA, PKC and CaMKII activity in rat hippocampus, while the effects of paroxetine on the protein kinases can be more complex in prefrontal cortex.

Animals ; Brain ; drug effects ; enzymology ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; metabolism ; Cyclic AMP-Dependent Protein Kinases ; metabolism ; Depression ; enzymology ; Disease Models, Animal ; Hippocampus ; drug effects ; enzymology ; Male ; Paroxetine ; pharmacology ; Protein Kinase C ; metabolism ; Random Allocation ; Rats

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

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