OBJECTIVETo explore the expression of p-p38 MAPK protein and the number of astrocytes expressing p-p38 MAPK in CA1 hippocampus in rats during the induction of brain ischemic tolerance induced by intermittent hypobaric hypoxia (IH) preconditioning.

METHODSThirty healthy adult male Wistar rats were randomly divided into 6 groups (n = 5 in each group): sham 0 min group, IH + sham 0 min group, sham 7 d group, IH + sham 7 d group, Ischemia (Is) 7 d group, and IH + Is 7 d group. Neuropathological evaluation was performed by thionine staining in CA1 hippocampus in rats. The expression of p-p38 MAPK in CA1 hippocampus was observed by immunohistochemical staining. And the number of astrocytes expressing p-p38 MAPK was observed by immunofluorescent double labeling.

RESULTSThe results showed that IH preconditioning induced brain ischemic tolerance successfully. At the same time, IH preconditioning obviously up-regulated the expression of p-p38 MAPK protein in CA1 hippocampus, and also increased the number of astrocytes expressing p-p38 MAPK.

CONCLUSIONIt might be concluded that IH preconditioning induced brain ischemic tolerance by up-regulating the expression of p-p38 MAPK protein in pyramidal neurones and astrocytes.

Animals ; Astrocytes ; enzymology ; pathology ; Brain Ischemia ; enzymology ; pathology ; Disease Models, Animal ; Hippocampus ; enzymology ; Hypoxia ; Ischemic Preconditioning ; methods ; Male ; Phosphorylation ; Pressure ; Rats ; Rats, Wistar ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo observe the effect of Huannao Yicong Prescription (, HNYC, a Chinese medical compound) extract on β-amyloid precursor protein (APP) metabolic signal transduction related protein kinase C (PKC), tyrosine amyloid protein kinase (TrKA), and glycogen synthase kinase-3 (GSK-3) in brain tissue of transgenic mouse dementia model induced by APP.

METHODSSixty dementia model transgenic 3-month-old mice induced by APP695V717I were randomly allocated in four groups: the model group (A), the Donepezil (0.65×10(-3) g·kg(-1)·(-1))-treated group (B), and the two HNYC-treated groups (C and D) with high dosage (2.8 g·kg(-1)·(-1)) and low dosage (1.4 g·kg(-1)·(-1)) of HNYC extract, respectively, 15 mice in each group. Besides, a normal control group was set up with 15 C57BL/6J mice with the same age and genetic background as the model mice. The drugs for treatment were administered once a day by dissolving in equal-volume distilled water through gastric infusion, continued for 6 months, to mice in group A and to normal control group equal-volume distilled water was administered instead. Spatial learning and memory capacity of mice were observed by Morris water maze; their one-time escape response memory capacity was tested by diving platform; and changes of PKC, TrkA, and GSK-3 levels in hippocampus and cortex of brain were detected by Western blotting.

RESULTSHNYC extract showed significant effects on increasing the time of model mice for swimming through the flat roof and the swimming time and path in the fourth quadrant P<0.05 or P<0.01). Diving platform test showed that the latent times in Groups B and C were longer than that in Group A significantly (P <0.05 and P<0.01). Compared with the normal control group, PKC and TrkA protein expression levels in hippocampus and cortex of model mice's brain lowered significantly (P<0.01), while GSK-3 protein expression increased significantly (P<0.01); compared with Group A (the model group), hippocampal and cortical levels of PKC protein expression in the intervened groups (B-D) as well as those of TrkA in Group C were higher (P<0.01 or P<0.05), while hippocampal levels of GSK-3 in intervened groups were lower (P<0.01).

CONCLUSIONHNYC extract could obviously increase the protein expressions of PKC and TrkA and decrease the expression of GSK-3 protein in brain tissue of transgenetic mice model of dementia, and regulate APP metabolic signal transduction path, and thus to suppress the production of Aβ, which is one of the dominant mechanisms for improving learning/memory capacity of dementia model animals.

Amyloid beta-Protein Precursor ; metabolism ; Animals ; Brain ; drug effects ; enzymology ; metabolism ; pathology ; Chromatography, High Pressure Liquid ; Dementia ; metabolism ; pathology ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Female ; Glycogen Synthase Kinase 3 ; metabolism ; Hippocampus ; drug effects ; metabolism ; pathology ; Male ; Memory ; drug effects ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Plant Extracts ; pharmacology ; Protein Kinase C ; metabolism ; Receptor, trkA ; metabolism ; Signal Transduction ; drug effects

OBJECTIVETo observe the effect of a Chinese medicine compound, Naoerkang (NEK), on amyloid-beta peptide (1-42; Aβ(1-42)) and matrix metalloproteinase-9 (MMP-9) expressions in the hippocampus of Alzheimer's disease (AD) model rats.

METHODSA total of 48 male Sprague Dawley (SD) rats were randomly divided into normal control, untreated, and piracetam groups, and low-dose, medium-dose, and high-dose NEK groups, with 8 rats in each group. The 5-μL aggregated Aβ(1-42) (2 μg/μL) were injected into both CA1 areas of the hippocampus in the rats to establish an AD model, whereas the normal control was treated with the same dose of normal saline. The rats in the NEK groups were treated with a high, medium, or low dose of NEK [60 g/(kg·d), 30 g/(kg·d), and 15 g/(kg·d)], respectively, intragastrically for 28 days; piracetam (0.375 g/kg, intragastrically) was consecutively administered in the piracetam group; and normal saline was applied in the normal control and untreated groups. A Y-maze test was used for behavioral study to test the learning and memory abilities. Aβ(1-42) and MMP-9 expressions in the hippocampus was determined immunohistochemically, and the results were analyzed by image acquisition and an analysis system.

RESULTSAggregated Aβ(1-42) induced obvious learning and memory dysfunction, as well as up-regulation of Aβ(1-42) expression in the hippocampus. Compared with those in the normal control group, the learning and memory abilities of rats in the untreated group significantly decreased (P<0.01), and the expression of Aβ(1-42) was significantly increased (P<0.01). Twenty-eight days after different treatments, compared with those in the untreated group, the learning and memory abilities of AD model rats in the piracetam, low-dose, medium-dose and high-dose NEK groups were significantly improved (P<0.01 or P<0.05), and the expression of Aβ(1-42) in the hippocampus decreased (P<0.01 or P<0.05), and MMP-9 increased (P<0.01 or P<0.05), especially in the high-dose NEK group.

CONCLUSIONNEK might play a role of anti-dementia by increasing the expression of MMP-9 in the hippocampus of AD model rats, resulting in the reduction of the quantity of Aβ(1-42) and improvement in learning and memory ability in AD model rats.

Alzheimer Disease ; drug therapy ; metabolism ; pathology ; physiopathology ; Amyloid beta-Peptides ; metabolism ; Animals ; CA1 Region, Hippocampal ; drug effects ; enzymology ; pathology ; physiopathology ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Hippocampus ; drug effects ; metabolism ; pathology ; physiopathology ; Immunohistochemistry ; Male ; Matrix Metalloproteinase 9 ; metabolism ; Memory ; drug effects ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo evaluate the improvement of Kangshuai Yizhi Formula I ( I, KYF I) on: the learning and memory dysfunction in mice, and on the mechanism of the hippocampal cholinergic system and the nervous system of monoamine which are closely related to learning and memory function.

METHODSMice: in the low-, middle-, and high-dose KYF I groups were given low-, middle-, and high-dose KYF, respectively, by gastrogavage for 35 successive days. Animals in the control group and the model group were treated with distilled water. The acute learning and memory dysfunction model was established by injection of scopolamine from day 31, and Morris water maze was used to assess the behavior performance of scopolamine-induced model mice for five days. The activities of acetylcholinesterase (AChE), choline acetyl transferase (ChaT) and the content of monoamine neurotransmitters in hippocampus were measured. The activity of monoamine oxidase (MAO) in hippocampus and serum was also detected.

RESULTS(1) Compared with the control group, the: mean escape latency was shortened, and the frequency across the platform and the staying time at the platform area on the 5th day were decreased in the model group by Morris water maze test. The activities of AChE and MAO were increased, and the ChaT activity and monoamine neurotransmitter content were decreased as well. (2) The escape latency for 4 days in the low-, middle-, and high-dose KYF I groups was significantly shortened than that in the model group, with the shortest latency in the high-dose KYF I group (P<0.05, P<0.01). The frequency across the platform was significantly increased and the staying time at the platform was significantly prolonged in the middle- and high-dose KYF I groups (P<0.05, P<0.01). (3) As compared with the model group, the activity of ChaT and the content of monoamine neurotransmitters in the hippocampus were significantly increased, and the activities of AchE and MAO were significantly decreased in the hippocampus in the high-dose KYF I group (P<0.01).

CONCLUSIONSHigh-dose KYF I can significantly improve the learning and memory dysfunction: induced by scopolamine in mice. Its mechanism may be related to improving the central cholinergic system and regulating the hippocampal monoamine neurotransmitters.

Acetylcholinesterase ; metabolism ; Animals ; Behavior, Animal ; drug effects ; Choline O-Acetyltransferase ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Hippocampus ; drug effects ; enzymology ; pathology ; Learning ; drug effects ; Male ; Memory Disorders ; blood ; drug therapy ; enzymology ; physiopathology ; Mice ; Monoamine Oxidase ; blood ; Neurotransmitter Agents ; metabolism ; Reaction Time ; Scopolamine Hydrobromide ; toxicity ; Time Factors

OBJECTIVETo study the effects and possible mechanisms of effective composite of Naodesheng (NDS) on permanent cerebral ischemia-induced injury in rats.

METHODSMale Sprague-Dawley rats: with middle cerebral artery occlusion (MCAO) were established with the modified suture method, and they were randomly divided into the following groups: the sham-operated group, the model group, the Nimodipine group (0.012 g/kg), the NDS group (1.075 g/kg), the total extracts group (0.23 g/kg), the high-dose NEC group (0.07 g/kg), the middle-dose NEC group (0.02 g/kg), and the low-dose NEC group (0.007 g/kg). The aforesaid medicines were administered at the 2nd, 4th, and 24th h after focal cerebral ischemia, and the infarction size and water content in the brain were evaluated at the 26th h after MCAO. Then, after oral administration once daily for 7 successive days, the changes in the degree of neurological deficit, oxidative stress, and apoptosis were measured on the 7th day.

RESULTSNEC could significantly reduce the infarction size after focal cerebral ischemia, and slightly relieve water content in the brain, significantly alleviate neurological function impairment, increase the levels of superoxide dismutase (SOD) and adenosine triphosphate enzyme (ATPase) activity, and decrease the content of malondialdehyde (MDA). NEC could also extenuate Bax and caspase-3 expression in the hippocampus tissue of the ischemic region. As compared with the three NEC treated groups, the high-dose NEC showed better efficacy.

CONCLUSIONSNEC could significantly reduce brain injury induced by ischemia;: its mechanism was closely associated with hindering oxidative stress and apoptosis. The effective composite-guided methodology is a feasible tool to improve the neuro-protective properties of the Chinese medicine guided prescription NDS against focal cerebral ischemia in rats.

Adenosine Triphosphatases ; metabolism ; Animals ; Blotting, Western ; Brain Ischemia ; prevention & control ; Caspase 3 ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Hippocampus ; enzymology ; metabolism ; pathology ; Male ; Malondialdehyde ; metabolism ; Neuroprotective Agents ; pharmacology ; Pyramidal Cells ; drug effects ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo examine modulations caused by cyclooxygenase-2 (COX-2) inhibitors on altered microenvironments and overbalanced neurotransmitters in pilocarpine-induced epileptic status rats and to investigate possible mechanisms.

METHODSCelecoxib (a COX-2 inhibitor) was administered 45 min prior to pilocarpine administration. The effects of COX-2 inhibitors on mIPSCs (miniature GABAergic inhibitory postsynaptic currents) of CA3 pyramidal cells in the hippocampus were recorded. Expressions of COX-2, c-Fos, newly generated neurons, and activated microgliosis were analyzed by immunohistochemistry, and expressions of alpha-subunit of gamma-amino butyric acid (GABA(A)) receptors and mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MAPK/ERK) activity were detected by Western blotting.

RESULTSPretreatment with celecoxib showed protection against pilocarpine-induced seizures. Celecoxib prevented microglia activation in the hilus and inhibited the abnormal neurogenesis and astrogliosis in the hippocampus by inhibiting MAPK/ERK activity and c-Fos transcription. Celecoxib also up-regulated the expression of GABA(A) receptors. NS-398 (N-2-cyclohexyloxy-4-nitrophenyl-methanesulfonamide), another COX-2 inhibitor, enhanced the frequency and decay time of mIPSCs.

CONCLUSIONThe COX-2 inhibitor celecoxib decreased neuronal excitability and prevented epileptogenesis in pilocarpine-induced status epilepticus rats. Celecoxib regulates synaptic reorganization by inhibiting astrogliosis and ectopic neurogenesis by attenuating MAPK/ERK signal activity, mediated by a GABAergic mechanism.

Animals ; Blotting, Western ; Celecoxib ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase 2 Inhibitors ; pharmacology ; Disease Models, Animal ; Fibrocystic Breast Disease ; metabolism ; Hippocampus ; drug effects ; enzymology ; pathology ; Immunohistochemistry ; MAP Kinase Signaling System ; drug effects ; Male ; Mitogen-Activated Protein Kinase Kinases ; metabolism ; Nitrobenzenes ; pharmacology ; Pilocarpine ; Proto-Oncogene Proteins c-fos ; metabolism ; Pyrazoles ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, GABA-A ; biosynthesis ; Status Epilepticus ; chemically induced ; enzymology ; pathology ; Sulfonamides ; pharmacology ; Synapses ; drug effects ; pathology

OBJECTIVETo investigate the relationship between the excitotoxicity and serum-inducible kinase (SNK) and spine-associated Rap GTPase-activating protein (SPAR) pathway in primary hippocampal neuron injury induced by glutamate and furthermore, to explore the molecular mechanism of neuroprotection of Zibu Piyin Recipe (ZBPYR) and the relationship between ZBPYR and the morphological regulation of dendritic spines.

METHODSThe serum containing ZBPYR was prepared by seropharmacology. Reverse transcription and polymerase chain reaction (RT-PCR) was used to detect the expression of mRNA for SNK, SPAR, postsynaptic density protein 95 (PSD-95) and N-methyl-D-aspartate (NMDA) receptor subunits (NR1, NR2A and NR2B) in primary rat hippocampal neuron cultures after pretreatment with 10 micromol/L glutamate and ZBPYR serum.

RESULTSZBPYR serum pretreatment resulted in a significant down-regulation of glutamate-induced SNK mRNA expression (P<0.05). Significant up-regulation was seen on the mRNA expression of SPAR and PSD-95 (P<0.05). All these changes were dose-dependent. The mRNA expression of NR1, NR2A and NR2B was down-regulated to different degrees (P<0.05).

CONCLUSIONThe mechanism of effect of ZBPYR on glutamate-induced excitotoxicity may be related to the regulation of SNK-SPAR signal pathway. ZBPYR may play a role in protecting and maintaining the normal morphology and structure of dendritic spines, which may be achieved by inhibiting the excessive activation of NMDA receptors.

Animals ; Cells, Cultured ; Disks Large Homolog 4 Protein ; Drugs, Chinese Herbal ; pharmacology ; GTPase-Activating Proteins ; genetics ; metabolism ; Gene Expression Regulation ; drug effects ; Glutamic Acid ; toxicity ; Hippocampus ; drug effects ; enzymology ; pathology ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Membrane Proteins ; genetics ; metabolism ; Neurons ; drug effects ; enzymology ; pathology ; Protein Kinases ; genetics ; metabolism ; Protein-Serine-Threonine Kinases ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Serum

OBJECTIVEExtracellular signal-regulated kinases (ERKs) can be activated by calcium signals. In this study, we investigated whether calcium-dependent kinases were involved in ERKs cascade activation after global cerebral ischemia.

METHODSCerebral ischemia was induced by four-vessel occlusion, and the calcium-dependent proteins were detected by immunoblot.

RESULTSLethal-simulated ischemia significantly resulted in ERKs activation in N-methyl-D-aspartate (NMDA) receptor-dependent manner, accompanying with differential upregulation of Src kinase and Ca2+/calmodulin-dependent protein kinase II (CaMKII) activities. With the inhibition of Src family tyrosine kinases or CaMKII by administration of PP2 or KN62, the phosphorylation of ERKs was impaired dramatically during post-ischemia recovery. However, ischemic challenge also repressed ERKs activity when Src kinase was excessively activated.

CONCLUSIONSrc family tyrosine kinases and CaMKII might be involved in the activation of ERKs mediated by NMDA receptor in response to acute ischemic stimuli in vivo, but the intense activation of Src kinase resulted from ischemia may play a reverse role in the ERKs cascade.

Analysis of Variance ; Animals ; Brain Ischemia ; enzymology ; pathology ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; Calcium-Calmodulin-Dependent Protein Kinases ; metabolism ; Disease Models, Animal ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Gene Expression Regulation ; physiology ; Hippocampus ; cytology ; enzymology ; Male ; Neurons ; enzymology ; pathology ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; metabolism ; Signal Transduction ; physiology ; Statistics, Nonparametric ; src-Family Kinases ; metabolism

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

OBJECTIVETo observe the improvement effects of puerarin on glycated brain damages in rat model induced by D-galactose.

METHODThe model rats of protein glycation were induced by intraperitoneal administration of D-galactose (150 mg x kg(-1) x d(-1)) for 8 weeks, and all rats were treated with puerarin (high dose 300 mg x kg(-1), middle dose 150 mg x kg(-1), low dose 75 mg x kg(-1)) for 6 weeks. The activity of aldose reductase in red blood cells, the amount of glycated products (fructosamine in serum, glycohaemoglobin, advanced glycation end-products) and AGEs in brain tissue, calcium ion in brain cells were measured. Moreover, mitochondria in brain hippocampus cells were observed under electronic microscope.

RESULTHigh dose and middle dose of puerarin can decrease the activity of aldose reductase in red blood cells (P < 0.01), and inhibit the formation of glycation products significantly in model rats induced by D-galactose (P < 0.01). Also, puerarin can decrease the content of AGEs in brain and the level of calcium ions in brain cells (P < 0.05, P < 0.01), and decrease lesions degree in mitochondria in brain hippocampus cells.

CONCLUSIONPuerarin can produce the protective effects on glycated brain damages through inhibiting the glycation reaction in rats induced by D-galactose.

Aldehyde Reductase ; metabolism ; Animals ; Brain ; metabolism ; pathology ; Calcium ; metabolism ; Erythrocytes ; enzymology ; Female ; Fructosamine ; blood ; Galactose ; antagonists & inhibitors ; Glycated Hemoglobin A ; metabolism ; Glycation End Products, Advanced ; metabolism ; Hippocampus ; ultrastructure ; Isoflavones ; isolation & purification ; pharmacology ; Male ; Mitochondria ; ultrastructure ; Neuroprotective Agents ; pharmacology ; Plants, Medicinal ; chemistry ; Pueraria ; chemistry ; Random Allocation ; Rats ; Rats, Sprague-Dawley