Stress and emotion are associated with several illnesses from headaches to heart diseases and immune deficiencies to central nervous system. Terminalia arjuna has been referred as traditional Indian medicine for several ailments. The present study aimed to elucidate the effect of T. arjuna bark extract (TA) against picrotoxin-induced anxiety. Forty two male Balb/c mice were randomly divided into six experimental groups (n = 7): control, diazepam (1.5 mg·kg), picrotoxin (1 mg·kg) and three TA treatemt groups (25, 50, and 100 mg/kg). Behavioral paradigms and PCR studies were performed to determine the effect of TA against picrotoxin-induced anxiety. The results showed that TA supplementation increased locomotion towards open arm (EPM) and illuminated area (light-dark box test), and increased rearing frequency (open field test) in a dose dependent manner, compared to picrotoxin (P < 0.05). Furthermore, TA increased number of licks and shocks in Vogel's conflict. PCR studies showed an up-regulation of several genes, such as BDNF, IP, DL, CREB, GABA, SOD, GPx, and GR in TA administered groups. In conclusion, alcoholic extract of TA bark showed protective activity against picrotoxin in mice by modulation of genes related to synaptic plasticity, neurotransmitters, and antioxidant enzymes.
Animals ; Antioxidants ; metabolism ; Anxiety Disorders ; drug therapy ; genetics ; metabolism ; psychology ; Brain-Derived Neurotrophic Factor ; genetics ; metabolism ; Dopamine Agents ; administration & dosage ; GABA Agents ; administration & dosage ; Glutathione Peroxidase ; genetics ; metabolism ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Neuronal Plasticity ; drug effects ; Neurotransmitter Agents ; metabolism ; Phytotherapy ; Picrotoxin ; adverse effects ; Plant Bark ; chemistry ; Plant Extracts ; administration & dosage ; Serotonin Agents ; administration & dosage ; Superoxide Dismutase-1 ; genetics ; metabolism ; Terminalia ; chemistry

OBJECTIVETo investigate the influence of cefuroxime sodium (CS) on the electrophysiological function of cerebellar Purkinje cells (PCs) in Sprague-Dawley rats.

METHODSPostnatal day 7 (P7) Sprague-Dawley rats were divided into early administration I and II groups (administered from P7 to P14) and late administration group (administered from P14 to P21), and all the groups received intraperitoneally injected CS. The control groups for early and late administration groups were also established and treated with intraperitoneally injected normal saline of the same volume. There were 10 rats in each group. The rats in the early administration I group and early administration control group were sacrificed on P15, and those in the early administration II group, late administration group, and late administration control group were sacrificed on P22. The whole-cell patch-clamp technique was used to record inward current and action potential of PCs on cerebellar slices, as well as the long-term depression (LTD) of excitatory postsynaptic current (EPSC) in PCs induced by low-frequency stimulation of parallel fiber (PF).

RESULTSCompared with the control groups, the early and late administration groups had a slightly higher magnitude of inward current and a slightly higher amplitude of action potential of PCs (P>0.05). All administration groups had a significantly higher degree of EPSC inhibition than the control groups (P<0.01), and the early administration II group had a significantly greater degree of EPSC inhibition than the late administration group (P<0.01).

CONCLUSIONSEarly CS exposure after birth affects the synaptic plasticity of PF-PCs in the cerebellum of young rats, which persists after drug withdrawal.

Animals ; Anti-Bacterial Agents ; pharmacology ; Cefuroxime ; pharmacology ; Excitatory Postsynaptic Potentials ; drug effects ; Neuronal Plasticity ; drug effects ; Purkinje Cells ; drug effects ; physiology ; Rats ; Rats, Sprague-Dawley

OBJECTIVEThe present study investigated the effects of rapamycin on Aβ1-42-induced deficits in working memory and synaptic plasticity.

METHODSAfter bilateral hippocampal injection of Aβ1-42 and rapamycinin rats, spontaneous alternation in Y-maze and in vivo hippocampal long-term potentiation (LTP) of rats were recorded. All data were analized by two-way repeated measures analysis of variance (ANOVA).

RESULTS(Hippocampal injection of Aβ1-42 alone impaired working memory of rats; (2) Rapamycin did not affect working memory of rats, but alleviated Aβ1-42-induced working memory deficits, compared with Aβ1-42 alone group; (Aβ1-42 remarkably suppressed in vivo hippocampal LTP of fEPSPs in the CA1 region; (4) Pretreatment with rapamycin prevented Aβ1-42-induced suppression of LTP.

CONCLUSIONThese data indicates that rapamycin could protect against Aβ1-42-induced impairments in working memory and synaptic plasticity in rats.

Amyloid beta-Peptides ; adverse effects ; Animals ; Hippocampus ; drug effects ; Long-Term Potentiation ; Maze Learning ; Memory, Short-Term ; drug effects ; Neuronal Plasticity ; drug effects ; Peptide Fragments ; adverse effects ; Rats ; Sirolimus ; pharmacology

OBJECTIVETo investigate the effect of aluminum exposure on neuronal apoptosis of rats hippocampus and the correlation of and synaptic plasticity.

METHODSThere were 40 SPF grade SD rats which were randomly divided into four groups: the control group, the low dose group, the medium dose group and the high dose group, 10 rats in each group. The rats were daily gavaged with aluminum lactate for 30 days. The hippocampal fEPSPs in rat was measured by electrophysiological grapher and the neuronal apoptosis in hippocampus was detected by Flow cytometer. In addition, the relative expression of gene which includes caspase-3, 8, 9 was measured by Real-time PCR.

RESULTSCompared to the control group, the average of fEPSPs which after HFS 10, 20, 30, 40, 50, 60 min was decreased at different time point in the low dose group, the medium dose group and the high dose group (P < 0.05). Compared with the control group, the rate of apoptosis was significantly increased in the medium dose group and the high dose group (P < 0.05). Compared to the control group, the relative expression of caspase-3 in the medium dose group and the high dose group was significantly increased in Real-time PCR (P < 0.05), and the relative expression of caspase-8 in the high dose group was significantly increased (P < 0.05).

CONCLUSIONAluminum exposure may induced neuronal apoptosis in rats, and then affect hippocampal synaptic plasticity.

Aluminum ; toxicity ; Aluminum Compounds ; toxicity ; Animals ; Apoptosis ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Hippocampus ; cytology ; drug effects ; Lactates ; toxicity ; Neuronal Plasticity ; drug effects ; Neurons ; cytology ; drug effects ; Rats ; Rats, Sprague-Dawley

The localization of estrogen (E2) has been clearly shown in hippocampus, called local hippocampal E2. It enhanced neuronal synaptic plasticity and protected neuron form cerebral ischemia, similar to those effects of exogenous E2. However, the interactive function of hippocampal and exogenous E2 on synaptic plasticity activation and neuroprotection is still elusive. By using hippocampal H19-7 cells, we demonstrated the local hippocampal E2 that totally suppressed by aromatase inhibitor anastrozole. Anastrozole also suppressed estrogen receptor (ER)beta, but not ERalpha, expression. Specific agonist of ERalpha (PPT) and ERbeta (DPN) restored ERbeta expression in anastrozole-treated cells. In combinatorial treatment with anastrozole and phosphoinositide kinase-3 (PI-3K) signaling inhibitor wortmannin, PPT could not improve hippocampal ERbeta expression. On the other hand, DPN induced basal ERbeta translocalization into nucleus of anastrozole-treated cells. Exogenous E2 increased synaptic plasticity markers expression in H19-7 cells. However, exogenous E2 could not enhance synaptic plasticity in anastrozole-treated group. Exogenous E2 also increased cell viability and B-cell lymphoma 2 (Bcl2) expression in H2O2-treated cells. In combined treatment of anastrozole and H2O2, exogenous E2 failed to enhance cell viability and Bcl2 expression in hippocampal H19-7 cells. Our results provided the evidence of the priming role of local hippocampal E2 on exogenous E2-enhanced synaptic plasticity and viability of hippocampal neurons.
Androstadienes/pharmacology ; Animals ; Aromatase Inhibitors/pharmacology ; Cell Line ; Cell Survival/drug effects ; Estrogen Receptor alpha/agonists/metabolism ; Estrogen Receptor beta/agonists/metabolism ; Estrogens/*metabolism/pharmacology ; Hippocampus/cytology/*metabolism ; Hydrogen Peroxide/pharmacology ; Nervous System/*drug effects ; Neuronal Plasticity/*drug effects ; *Neuroprotective Agents ; Nitriles/pharmacology ; Phosphatidylinositol 3-Kinase/antagonists & inhibitors ; Proto-Oncogene Proteins c-bcl-2/biosynthesis ; Rats ; Triazoles/pharmacology

OBJECTIVETo explore effects of acrylamide on synaptic plasticity of rat neuron and its mechanisms.

METHODS24 Wistar rats were divided into control and test groups randomly, 12 rats in each group. The ratio of male and female in each group was 1:1. Acrylamide (30 mg/kg) was administered to rats by intraperitoneal injection in test group and normal saline (5 g/kg) was given to rats in control group. The neurobehavioral and pathologic changes of heart, liver, spleen, lung and kidney were observed. Changes of parameters in synapse were recorded by electron microscope. As an important target of synapse, change of Synapsin I was measured by immunohistochemical method.

RESULTSCompared with the control group (male: 1.00 ± 0.00; female: 1.00 ± 0.00), the gait score was increased significantly in ACR treated group (male: 2.50 ± 0.55, t = -7.24, P < 0.01; female: 3.17 ± 0.41, t = -12.19, P < 0.01). No obvious pathological changes of heart, liver, spleen, lung and kidney were found in all rats. Compared with the control group (male: (0.41 ± 0.09) µm; female: (0.40 ± 0.06) µm), the length of active zone of synapse was decreased significantly in ACR treated group (male: (0.15 ± 0.05) µm, t = 6.59, P < 0.05; female: (0.14 ± 0.07) µm, t = 7.26, P < 0.05). The width and postsynaptic density of synapse in ACR treated group had no significant difference with control group. The location of Synapsin I of control group and ACR treated group was both in gray matter of spinal dorsal horn. Compared with the control group (male: 195.40 ± 12.30; female: 195.19 ± 6.71), the concentration of Synapsin I was decreased significantly in ACR treated group (male: 60.90 ± 29.19, t = 10.40, P < 0.05; female: 67.56 ± 20.23, t = 15.65, P < 0.05).

CONCLUSIONNeuronal synaptic plasticity was found in damage of nervous system induced by acrylamide in rats, which might be associated with the expression of Synapsin I.

Acrylamide ; toxicity ; Animals ; Female ; Male ; Neuronal Plasticity ; drug effects ; Neurons ; drug effects ; Rats ; Rats, Wistar ; Synapses ; drug effects

Synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD), is widely considered as one of the major mechanisms underlying learning and memory. This study explored hippocampal synaptic plasticity and spatial memory formation of an Alzheimer's disease (AD) rat model established by intrahippocampal injection of oligomeric Aβ(1-42). Twenty four Sprague-Dawley rats at 2.5 months of age were randomly divided into AD and control groups, and were bilaterally injected with 5 μg oligomeric Aβ(1-42) or normal saline into dentate gyrus (DG) of hippocampus. Morris water maze test was used to observe the capability of learning and memory of two groups, 30 d after injection. To investigate the variations of paired-pulse facilitation (PPF) and range of synaptic plasticity, field potentials were recorded in the DG of the dorsal hippocampus by stimulating the perforant path (PP). The results showed that oligomeric Aβ(1-42) obviously impaired spatial memory formation in rats (P < 0.05). Furthermore, oligomeric Aβ(1-42) reduced the PPF ratio (P < 0.05) and hippocampal LTP formation (P < 0.05), while facilitated the hippocampal LTD formation (P < 0.05). These data suggest that chronic Aβ aggregation impairs synaptic plasticity of hippocampal PP-DG pathway, which may be involved in the spatial memory deficit in AD rats.
Alzheimer Disease ; chemically induced ; physiopathology ; Amyloid beta-Peptides ; toxicity ; Animals ; Female ; Hippocampus ; physiopathology ; Long-Term Potentiation ; drug effects ; physiology ; Long-Term Synaptic Depression ; drug effects ; physiology ; Male ; Maze Learning ; Memory ; physiology ; Neuronal Plasticity ; drug effects ; physiology ; Oligopeptides ; toxicity ; Peptide Fragments ; toxicity ; Perforant Pathway ; physiology ; Rats ; Rats, Sprague-Dawley ; Synapses ; drug effects ; physiology

Although the impairing effects of beta-amyloid (Aβ) protein on synaptic plasticity and cognitive function have been widely reported, the mechanisms underlying the neurotoxicity of Aβ are still not well known. The present study observed the effects of intracerebroventricular (i.c.v.) injection of both Aβ(23-35) and genistein (a specific tyrosine kinase inhibitor at high concentration) on the hippocampal long-term potentiation (LTP) in the CA1 region, and investigated its possible protein tyrosine kinase (PTK) mechanism. Male Wistar rats were surgically prepared for acute LTP recordings in vivo. Two parallel bond electrodes for stimulating and recording were simultaneously inserted into the right hippocampus of rats. The field excitatory postsynaptic potentials (fEPSPs), paired-pulse facilitation (PPF) and high-frequency stimuli (HFS)-induced LTP were recorded by delivering test stimuli, paired pulses and HFS to the Schaffer-collateral/commissural pathway. The results showed that: (1) i.c.v. injection of Aβ(23-35) did not affect the baseline synaptic transmission, but significantly suppressed the HFS-induced LTP, with a decreased average amplitude of fEPSPs [(129.2+/-6.7)% in 10 nmol Aβ(23-35) group; (110.6+/-8.6)% in 20 nmol Aβ(23-35) group; P<0.01] at 1 h post-HFS when compared to that in the control group [(163.1+/-8.1)%]; (2) Similarly, i.c.v. injection of genistein (200 nmol) did not change the basic synaptic transmission, but significantly suppressed HFS-induced LTP, with the similar average amplitude of fEPSPs [(114.0+/-7.2)%] at 1 h post-HFS to that in 20 nmol Aβ(23-35) group; (3) Co-application of Aβ(23-35) (20 nmol) and genistein (200 nmol) caused no additive suppression of LTP, and the average amplitude of fEPSPs was (113.0+/-8.8)% at 1 h post-HFS, showing no significant difference when compared with that in Aβ(23-35) or genistein alone groups (P>0.05); (4) There was no significant change in the PPF following genistein and Aβ(23-35) alone or co-injection (P>0.05). These experimental results indicate that i.c.v. injection of Aβ(23-35) can significantly suppress the HFS-induced LTP in the CA1 area of rat hippocampus in vivo, implying that the Aβ deposited in the brain of patients with Alzheimer's disease may impair the function of learning and memory by suppressing the hippocampal LTP. The facts that the extent of inhibition of Aβ(23-35) and genistein on LTP was similar and no further potentiation of the suppression was observed when Aβ(23-35) and genistein were co-applied suggest that PTK is probably involved in the Aβ-induced suppression of hippocampal LTP.
Amyloid beta-Peptides ; pharmacology ; Animals ; CA1 Region, Hippocampal ; drug effects ; enzymology ; Excitatory Postsynaptic Potentials ; Genistein ; pharmacology ; Long-Term Potentiation ; Male ; Neuronal Plasticity ; Peptide Fragments ; pharmacology ; Protein Kinase Inhibitors ; pharmacology ; Protein-Tyrosine Kinases ; metabolism ; Rats ; Rats, Wistar ; Synaptic Transmission

OBJECTIVETo investigate the effects of ephedrine combined with various doses of naloxone on neural plasticity in rats after cerebral ischemia/reperfusion injury to explore the possibility of synergistic effect about ephedrine combined with naloxone, promoting the optimum ratio of neural remodeling and its molecular mechanism.

METHODA total of 192 healthy adult Sprague-Dawley rats, 220-250 g, were used to establish models of left middle cerebral artery occlusion using the suture occlusion method. Were randomly divided into 8 groups: the rats were intraperitoneally injected with 1.5 mg x kg(-1) x d(-1) ephedrine (ephedrine group), with 0.1, 0.2, 0.3 mg x kg(-1) x d(-1) naloxone (low, moderate and high doses of naloxone groups) , with 1.5 mg x kg(-1) x d(-1) ephedrine + 0.1, 0.2, 0.3 mg x kg(-1) x d(-1) naloxone (ephedrine + low, moderate and high doses of naloxone groups), and with 0.5 mL saline (model group), respectively. At 1-4 weeks following cerebral ischemia, sensorimotor integration in rats was assessed using the beam walking test, brain-derived neurotrophic factor (BDNF) expression was detected in the hippocampal CA3 area using immunohistochemistry 1-4 weeks after surgery, immunofluorescence method of detecting ischemic hemisphere hippocampal expression, The number of nerve cells apoptosis was detected using TUNEL assay.

RESULTBWT, BDNF, TUNEL assay results showed three doses of naloxone group had no significant effect, the effects increased together with the quantitative ephedrine, and had the amount-effect relationship, in which ephedrine + high dose of naloxone group the recovery of movement was fastest, BDNF expression in the best and ischemic apoptosis in the hippocampus at least, ischemic injury to the minimum, speed up the process of neural remodeling.

CONCLUSIONThe ephedrine and ephedrine + naloxone groups were accelerated motor function recovery rate in rat after cerebral ischemia, and the promotion of neural remodeling is closely related to the expression of BDNF, inhibit apoptosis in ischemic area, and with the increase of naloxone amount of additives, its role more clearly, the mechanism may be related to the dose of naloxone can significantly inhibit the ischemic area of apoptosis in early cerebral ischemia, so had the positive synergy effect with ephedrine to speed up the formation of neural remodeling.

Animals ; Apoptosis ; drug effects ; Brain Ischemia ; drug therapy ; genetics ; metabolism ; physiopathology ; Brain-Derived Neurotrophic Factor ; genetics ; metabolism ; Disease Models, Animal ; Ephedrine ; administration & dosage ; Female ; Hippocampus ; drug effects ; metabolism ; physiopathology ; Humans ; Male ; Naloxone ; administration & dosage ; Neuronal Plasticity ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley

In recent decades, scientists in Asian and Western countries have been paying great attention to ginseng research. Today, more than 200 ginsenosides and non-saponin constituents have been isolated and identified. Ginsenosides show biological activities only after being deglycosylated by intestinal bacteria. Aglycone protopanaxadiol and protopanaxatriol show the highest bioactivities. According to literature, the noticeable action of ginseng is that of delaying aging and especially increasing the nootropic effect, and it was found for the first time that Rg1 could increase hippocampal neurogenesis in vitro and in vivo under physiological and pathological circumstances. This is one of primary mechanisms underlying many of its pharmacological actions on the central nervous system. Rg1 was further shown to improve learning and memory in normal rats and mice. The nootropic signaling pathway has also been carried out in normal rats, and the Rg1-induced signaling pathway is similar to the memory formation that occurs in mammals, suggesting that Rg1 may have a potential effect in increasing intellectual capacity in normal people. Comparisons of chemical structures and pharmacologic functions between Panax ginseng and Panax quiquefolium were carried out by many scientists. The conclusion is that each has its own characteristics. There is no superiority or inferiority to the other.
Animals ; Cognition ; drug effects ; Ginsenosides ; pharmacology ; Humans ; Learning ; drug effects ; Memory ; drug effects ; Mice ; Neovascularization, Physiologic ; Neurogenesis ; Neuronal Plasticity ; drug effects ; Panax ; chemistry ; Rats ; Signal Transduction ; drug effects