Effects of Astragalus injection on neuronal apoptosis and expression of JNK3 in rat hippocampus after cerebral ischemia reperfusion

AIM:To investigate the effects of Astragalus injection on neuronal apoptosis and expression of c-Jun N-terminal kinase 3(JNK3) in the rat hippocampus after cerebral ischemia reperfusion. METHODS:The rat model of cerebral ischemia reperfusion was set up by a four-vessel occlusion method. The SD rats were randomly divided into 4 groups:sham operation group, cerebral ischemia reperfusion group(model group), cerebral ischemia reperfusion+Astragalus injection group(Astragalus injection group) and cerebral ischemia reperfusion+vehicle group(vehicle group). The rats in model group, Astragalus injection group and vehicle group after transient global cerebral ischemia(30 min) were then divided into 7 subgroups according to the reperfusion time of 0 h, 0.5 h, 2 h, 6 h, 24 h, 72 h and 120 h. The apoptosis of the neuron in the hippocampus was measured by the method of TUNEL staining. The expression of JNK3 at mRNA and protein levels was determined by real-time PCR and Western blotting,respectively. RESULTS:Compared with sham operation group, the number of apoptotic neurons increased in model group(P<0.05). Compared with model group, the number of apoptotic neurons decreased obviously in Astragalus injection group(P<0.05). Compared with sham operation group, the expression of JNK3 at mRNA and protein levels in the hippocampus increased obviously in model group at all time points except 120 h(P<0.05). Compared with model group, the expression of JNK3 at mRNA and protein levels in the hippocampus decreased obviously in Astragalus injection group at all time points except 120 h(P<0.05). CONCLUSION:Astragalus injection decreases neuronal apoptosis in rat hippocampus after cerebral ischemia reperfusion by inhibiting the expression of JNK3 at mRNA and protein levels.     

Effects of hippocampus NE or Ach system disfunction on P3-like potential in rats

AIM: To study the change in cognitive function in derogative state of different neurotransmitter by mensurating P300 amplitude and latency. METHODS: Acetylcholine (ACh) system was disfunctioned by severing fimbrial-fornix(FF) transaction and Norepinephrine (NE) system impaired by injection of 6-hydroxysopamine into the bilateral dorsal noradrenergic bundle in DG. Then Y-type maze test and elicitation of P3-like latency were carried out separately before and after the all models were built. RESULTS: In both experimental groups, P3-like latency was prolonged significantly compared with the control and had positive correlation with indices of Y-maze test(EN,TRT). CONCLUSION: ACh and NE are important in the production and conformity of P300.     

Relationship between meso-hippocampal dopaminergic projections and hippocampal P300-like potentials in rats

AIM: To evaluate the role of the meso-hippocampal dopaminergic systems in the generation of hippocampal P300-like potentials. METHODS: Changes of ventral hippocampal P300-like potentials were examined after lesions of the meso-hippocampal dopaminergic systems.The extracellular DA and DOPAC were collected by the push-pull method in the ventral and dorsal hippocampus and their contents were measured by high-performance liquid chromatography with electrochemical detection(HPLC-EC). RESULTS: The contents of DA and DOPAC in the ventral hippocampus were higher than those in the dorsal hippocampus in the normal animals. The peak latencies of P300-like potentials were prolonged and the contents of DA and DOPAC decreased in the ventral hippocampi after lesions of the meso-hippocampal dopaminergic systems. CONCLUSIONS: There exist meso-hippocampal dopaminergic systems in rats;The meso-hippocampal dopaminergic terminals is mainly located in the ventral hippocampal area in rats; The meso-hippocampal dopaminergic projections take part in the generation of the hippocampal P300-like potentials in rats.     

Effects of light intensity,stocking density and temperature on the air-bubble disease,survivorship and growth of early juvenile seahorse Hippocampus erectus Perry, 1810

This investigation examined the effects of light intensity, stocking density and temperature on the air-bubble disease, survivorship and growth of early juveniles (2–30 days old) of seahorse Hippocampus erectus Perry. The juveniles in the 100 lx treatment had the highest air-bubble disease rate of 20.8 ± 6.2% and the juveniles in the 500 lx treatment had the highest survival rate of 84.4 ± 5.5%. The juvenile seahorses cultured in the 1500 lx treatment had the highest final wet weight of 0.13 ± 0.02 g and the highest final standard length of 4.54 ± 0.37 cm (F_{7, 144}=57.406, F_{7, 144}=12.315, P<0.05). There was no significant effect of stocking density on the air-bubble disease rate (F_{6, 21}=1.893, P=0.126). The juveniles cultured in the 1 ind L⁻¹ had the highest wet weight increment of 0.134 ± 0.031 g, but juveniles in the 2 ind L⁻¹ had the highest standard length increment of 3.17 ± 0.30 cm (F_{6, 126}=34.902, F_{6, 126}=11.726, P<0.05), and juveniles cultured in the 1.5 ind L⁻¹ had the highest survival rate of 86.1 ± 4.6%. The result of interaction of light intensity and temperature showed that the juveniles cultured in the 1500 lx and 26 °C had the highest weight gain and specific growth rate of 3791.17 ± 323.97% and 13.07 ± 0.18, respectively, and the lowest air-bubble disease rate of 9.3 ± 4.5% occurred in the 1000 lx and 26 °C (F_{8, 36}=12.355, P<0.05).     

Altered expression of G protein-coupled inwardly rectifier potassium channels (GIRK) subunit 1 and 2 in hippocampus of chronic temporal epileptic rats induced by kainic acid

AIM: G protein-coupled inwardly rectifier potassium (GIRK) channel are distributed widely in mammalian brain. In CNS, GIRK 1/2 seems to be the predominant heterotetramers which play a pivot role in the regulation of the excitability of neurons and may contribute to the resting potential by leading to a hyperpolarization of membrane potential and reduction of the action potential frequency. In the context, the Weaver mouse is the first neurological abnormality directly linked to a genetic point mutation in the GIRK2 protein which includes spontaneous seizure. GIRK2 knock out mice showed normal development but more susceptible than normal mice to seizure induced by GABA antagonist. Here, we report that the mRNA and protein expression of GIRK subunit 2 is altered in kainic acid(KA)-induced epileptic rat hippocampus. METHODS: Rats were injected with kainate 14 mg/kg intraperitoneally to establish an acute and chronic temporal lobe epilepsy model. At chronic spontaneous seizure stage, by using of in situ hybridization, immunocytochemistry and Western blotting, the GIRK 1,2 mRNA and protein were analyzed quantitatively in the dentate gyreus, CA1, CA3 regions of hippocampus. RESULTS: GIRK1,2 mRNA and proteins were expressed abundantly in all regions of hippocampus. KA induced seizures and caused a significant increase in GIRK2 mRNA abundance and immunoreacitivity; only GIRK1 mRNA was increased significantly, but no difference was found by Western blotting protocol. CONCLUSION: GIRK1,2 mRNA and protein expression in the hippocampus of epileptic rat brain is up-regulated, which may be an adaptive response to over-excitability of neuron networks and prevent the over-excitability spread in hippocampus (DG-CA3-CA1).     

α-硫辛酸对铅暴露海马神经元突触生成的影响和保护机制

[目的]探讨α-硫辛酸对铅暴露大鼠海马神经元树突棘突触形成的神经保护作用和机制.[方法]取新生大鼠(出生后24h内,P0)海马组织进行细胞培养,体外培养第6天(DIV6)转染绿色荧光蛋白(GFP),DIV7开始加入醋酸铅(1nol/L)处理至试验结束(DIV13),并在DIV12给予α-硫辛酸(100 nmol/L,1μmol/L和10 μmol/L)处理24h,然后观察树突棘的变化并进行量化分析.整体动物试验以SD母鼠喂饲300 mg/L醋酸铅水溶液,幼鼠自出生后至断奶(出生后第21天)经母乳铅暴露.幼鼠自从出生后第14天(PND14)到PND21经腹腔注射给药25 mg/kg α-硫辛酸,研究LA对铅暴露的海马神经元海马树突棘的修复作用,检测海马AMPA和NMDA受体的表达水平.[结果]α-硫辛酸对铅处理的体外培养海马神经元树突棘密度损伤有保护作用,且呈剂量依赖性.整体动物试验发现,铅暴露能显著降低海马CA1区锥体神经元和DG区颗粒细胞的树突棘密度.α-硫辛酸可以显著上调突触后NMDA受体亚单位NR2B的表达(P＜0.05),但不影响AMPA受体亚单位的合成和表达.[结论]α-硫辛酸可以修复铅暴露引起的突触损伤,富含α-硫辛酸的食品可防治儿童铅中毒.     

Growth and survival of juvenile seahorse Hippocampus abdominalis reared on live, frozen and artificial foods

The culture of seahorses has usually relied on cultured live foods or collected wild live foods as feed. This can be expensive in the case of culturing live foods and unreliable in the case of harvesting wild live foods. This investigation examined whether juvenile Hippocampus abdominalis from 0 to 2 months of age could be experimentally weaned onto frozen (Cyclop-eeze copepods) and artificial (Golden Pearls) food over 30-day periods with Artemia as a live food control, with 0-, 5-, 10-, and 20-day mixed feeding periods. Newborn juveniles could not be weaned onto Golden Pearls, with almost complete mortality. One-month-old juveniles could be weaned onto Cyclop-eeze with no effect on survival but with lower growth. One-month-old juveniles could be weaned onto Golden Pearls but with lower survival and lower growth. Two-month-old juveniles could be weaned onto Cyclop-eeze but with lower survival and lower growth. Two-month-old juveniles could be weaned onto Golden Pearls with no effect on survival but with lower growth. In all experiments, the rate of feeding strikes on Cyclop-eeze and Golden Pearls was lower than that on Artemia (e.g. range of mean 0.16–0.97 vs. 2.2–2.76 feeding strikes/min), both when Artemia were the sole food presented and when Artemia were cofed with the nonlive foods. However, mixed feeding Artemia with nonlive foods did appear to increase the rate of feeding strikes on nonlive foods. These results indicate the potential for incorporating more cost effective and reliable nonlive foods into seahorse culture.     

人工养殖条件下大海马幼鱼的生长

在人工养殖条件下 ,研究大海马 (HippocampuskudaBleeker)幼鱼的生长特性及其成活率。结果表明 ,大海马幼鱼的最大增长率为 1 5 88% ,最大增重率为 52 94% ,最小增长率为 2 80 % ,最小增重率为 8 0 5 % ,群体增重倍数为 7 2 0 ,幼鱼的平均日增长率和日增重率分别为 0 44mm/d和0 0 0 5 2g/d。大海马幼鱼体长与日龄的关系式为L =1 5 2 8+0 40 6 5T ,体重与日龄的关系式为W=1 865× 1 0 -4 T1 6872 ,体重与体长的关系式为W =6 884× 1 0 -6L2 762 2 。大海马幼鱼的成活率为90 4%。     

ATPase activities and Ca2+/calmodulin alterations in hippocampi of rats with PTSD-like behaviors

AIM: To explore the pathophysiological bases in the pathogenesis of the lasting emotional behavioral disorders following posttraumatic stress disorder(PTSD). METHODS: 240 male Wistar rats were divided randomly into 3 groups. Group SE(n =96) for rats with PTSD-like behavior by constant pulsating current of 100 μA with intratrain frequencies of 16 Hz, pulsating duration of 1 ms, train duration of 10 s and interstimulus interval of 7 min for 5 days with 8 times per day. Group CE(n =96) for control with electrode implanted in hippocampus without stimulation, and Group NC(n =48) for normal control. The activities of Na⁺-K⁺-ATPase and Ca²⁺ -ATPase, levels of intracellular calcium and free calmodulin(CaM), and the total CaM expression were detected in hippocampi of experimental rats. RESULTS: The activities of Na⁺-K⁺-ATPase and Ca²⁺ -ATPase in mitochondria of hippocampal cells in Group SE rats were significantly decreased at 48 h and 72 h after the last stimulation, respectively. The intracellular free calcium levels were increased, and the mean channel fluorescence of intracellular free CaM decreased remarkably at 72 h poststimulation, while the expression of total CaM was significantly elevated at 48 h after the last stimulation in hippocampi of Group SE rats. CONCLUSION: The lasting increased levels of intracellular free calcium and expression of Ca²⁺ -CaM in hippocampus, as well as the dysfunction of Na⁺-K⁺ pump and Ca²⁺ -ATPase in mitochondria may play important roles in the long-term neuropsychological sequelae in PTSD.