A circuit from dorsal hippocampal CA3 to parvafox nucleus mediates social novelty preference deficits induced by chronic social defeat stress / 中国药理学与毒理学杂志

OBJECTIVE The preference for social novelty is crucial to the social life of humans and rodents.However,the neural mechanisms underlying social novelty preference are poorly understood.Dorsal hippocampal CA3(dCA3)is an important brain area that responds to social defeat stress,and the neural circuitry of dCA3→lat-eral septum(LS)participates in the context-associated memory.Meanwhile,the parvafox nucleus(PFN)Foxb1+ neurons regulate the defensive reaction to life-threaten-ing situations.Therefore,we investigate a cell-specific cir-cuit of dCA3CaMKⅡα+→dorsal LSGABA+→PFNFoxb1+ in social novelty preference.METHODS Chronic social defeat stress(CSDS)and three-chamber social interaction test were performed in adult male C57BL/6J mice to detect social behaviors.Optogenetic and chemical-genetic experiments were conducted to regulate the circuit.RESULTS CSDS reduced the preference for social nov-elty in mice and the response of dCA3CaMKⅡα+ neurons dur-ing approach to an unfamiliar mouse was impaired by CSDS.Optogenetic inhibition of dCA3CaMKⅡα+→dLS pro-jection reduced the preference for the unfamiliar mouse versus a familiar mouse.Meanwhile,optogenetic activa-tion of dCA3CaMKⅡα+→dLS projection rescued the prefer-ence for social novelty of CSDS-treated mice.Manipula-tions dLSGABA+→PFN projection activation regulated the preference for social novelty in mice.Optogenetic activa-tion of PFNFoxb1+→lPAG projection reduced the prefer-ence for a familiar C57BL/6J mouse versus a novel object in control mice.CSDS decreased the excitability of dCA3CaMKⅡα+ neurons by up-regulation of Kir2.4(Kcnj14)expression.CONCLUSION Our present study suggest-ed that activation of a cell-specific circuit of dCA3CaMKⅡα+→dLSGABA+→PFNFoxb1+→lPAG reverses the deficits of social novelty preference in defeated mice,and inhibition of this circuit reduces the preference for social novelty.The cir-cuit that regulates the preference for social novelty deficits may provide a new information for the potential therapeu-tic targets for neuropsychiatric diseases.

1-triacontanol cerotate isolated from Marsilea quadrifolia Linn. safeguards hippocampal CA3 neurons and augments special memory deficit in chronic epileptic rats / Cerotato de 1-triacontanol aislado de Marsilea quadrifolia Linn. protege las neuronas CA3 del hipocampo y mejora el déficit de memoria especial en ratas epilépticas crónicas

SUMMARY: Currently many people with epilepsy do not have seizure control even with the best available medications. Moreover various antiepileptics have adverse cognitive impact with other side effect. Thus, need for new antiepileptic drugs still remains challenge. However, many of the natural components have antiepileptic action and this fact remains scientifically unexplored. This study was designed to check the behavioral and neuro-pathological outcome of 1-Triacontanol cerotate (1TAC), isolated from Marsilea quadrifolia Linn. (MQ) on chronic Pentylenetetrazol (PTZ) kindling model of epilepsy in rats. Two-month-old adult male Wistar rats (n=60) were randomly divided into six groups; Group I (Cage Control), II (Vehicle Control), III (Positive Control), IV (Standard drug treated), V (1TAC: 40 mg/kg) & VI (1TAC: 80 mg/kg). To induce kindling a 35 mg/kg dose of PTZ was injected i.p. in every 48 hrs for 30 days in Group III to VI. Spatial memory performance was tested using Morris water maze, following which brains were further processed for histopathological investigations. Interestingly, 1TAC was able to minimize the loss of pyramidal cells in hippocampal CA3 region. These cellular changes were behaviorally responded as improved special learning and memory, a better spatial navigation and object place configuration. The current study strongly implicates that 1TAC from MQ has potent neuroprotective role and augments special memory deficit in chronic epileptic rats. The isolated component which attenuates spatial memory performance could be beneficial outcome to retain cognitive blunting in chronic epilepsy.

RESUMEN: Actualmente, muchas personas con epilepsia no cuentan con un control adecuado de las convulsiones, incluso con los mejores medicamentos disponibles. Además, varios antiepilépticos tienen un impacto cognitivo adverso además de efectos secundarios. Por lo tanto, la necesidad de nuevos fármacos antiepilépticos sigue siendo un desafío. Sin embargo, muchos de los componentes naturales tienen acción antiepiléptica y este hecho permanece científicamente inexplorado. Este estudio se diseñó para verificar el resultado conductual y neuro-patológico del cerotato de 1-triacontanol (1TAC), aislado de Marsilea quadrifolia Linn. (MQ) en el modelo de epilepsia en ratas del pentilenetetrazol (PTZ) crónico (PTZ). Ratas Wistar adultas de dos meses de edad (n = 60) se dividieron aleatoriamente en seis grupos; Grupo I (Control de jaula), II (Control de vehículo), III (Control positivo), IV (Medicamento estándar de tratamiento), V (1TAC: 40 mg / kg) y VI (1TAC: 80 mg / kg). Para inducir la inflamación se inyectó una dosis de 35 mg / kg de PTZ i.p. en cada 48 horas durante 30 días en los grupos III a VI. El rendimiento de la memoria espacial se probó utilizando el laberinto de agua de Morris, después de lo cual se procesaron los cerebros para investigaciones histopatológicas. Curiosamente, 1TAC pudo minimizar la pérdida de células piramidales en la región CA3 del hipocampo. Estos cambios celulares respondieron de manera conductual como una mejora del aprendizaje especial y la memoria, una mejor navegación espacial y la configuración del lugar del objeto. El estudio actual implica fuertemente que 1TAC de MQ tiene un potente papel neuroprotector y mejora el déficit de memoria especial en ratas epilépticas crónicas. El componente aislado que atenúa el rendimiento de la memoria espacial podría ser un resultado beneficioso para retener la reducción cognitiva en la epilepsia crónica.

Effects of electroacupuncture on synaptic plasticity in hippocampal CA3 area of rats with chronic stress depression / 中国针灸

<p><b>OBJECTIVE</b>To explore the effects of electroacupuncture (EA) on behavioral function and synaptic plasticity in hippocampal CA3 area in rats with chronic stress depression.</p><p><b>METHODS</b>According to the random number table method, 144 SD male rats were assigned into a blank group, a model group, an EA group and a fluoxetine group, then each group was divided into a 7 d subgroup, a 14 d subgroup and a 21 d subgroup, 12 rats in each subgroup. The chronic mild unpredictable stress stimulus combined with lonely breeding were applied to establish the depression model of rats, which was performed simultaneously with intervention treatment. The rats in the EA group were treated with EA (dilatational wave) at "Shenting" (GV 24) and "Baihui" (GV 20), while the rats in fluoxetine group were treated with intragastric administration of fluoxetine, once daily. With open-field test, sugar consumption experiment and transmission electron microscope, the changes of behavior and neuronal synapse inhippocampal CA3 area were observed.</p><p><b>RESULTS</b>On 7 d, 14 d and 21 d, compared with the blank group, the open-field test score, sugar consumption and body mass were significantly lower in the model group (all<0.01); compared with the model group, the open-field test score, sugar consumption and body mass were significantly higher in the EA group and the fluoxetine group on 14 d and 21 d (<0.01,<0.05). On 14 d and 21 d, compared with the blank group, the synapse in hippocampal CA3 area was significantly lower in the model group (both<0.01); compared with the model group, the synapse in hippocampal CA3 area was significantly higher in the EA group and the fluoxetine group (<0.01,<0.05). The neurons cells in hippocampal CA3 area in the model group showed pyknosis and deformation from 7 d with fusion structure and unclear boundary of synapse, which were significantly improved on 21 d; the neurons cells in hippocampal CA3 area in the EA group and the fluoxetine group were significantly improved from 14 d and restored to normal level on 21 d, in addition, the structure of synapse restored to normal level.</p><p><b>CONCLUSIONS</b>EA is involved in the regulation of synaptic plasticity in hippocampal CA3 area, and promotes the recovery of depression symptoms.</p>

Effect of Mobile Phone Radiofrequency On Hippocampal Ca3 Neurons.

Objective: The purpose of the study is to investigate the effects of mobile phone [MP] radiofrequency electromagnetic fields (RF-EMF) exposure for different durations on dendritic morphology and nerve cell damage in CA3 sub region of Hippocampus in Swiss albino mice. Materials &Methods: Total 70 Swiss albino mice of both sexes were used in the study. Animals were divided into 10 groups randomly. Five groups (n=6) were used for assessment of neuronal damage by cresyl violet staining. Another five groups (n=8) were used for assessment of dendritic morphology by Golgi- Cox staining. Groups were divided by exposure duration (15, 30, 45 and 60 minutes/ per day for 30 days); age matched unexposed groups served as controls. Results: Results of the study have shown that there was decrease in the number of viable neurons and dendritic arborization in CA3 sub region of hippocampus in 30, 45 and 60 min exposed groups. Conclusions: Increased neuronal damage and decreased dendritic arborization of hippocampal CA3 neurons was found with increase in exposure duration of MPRF-EMF.

Effects of Baishile Capsules on Neurogenesis Related Protein in Hippocampal DG and CA3 ;Area of Model Rats with Chronic Unpredicted Mile Stress Depression / 中国中医药信息杂志

Objective To investigate effects of Baishile Capsules on cAMP-CREB-BDNF signal pathway about hippocampal neurogenesis in model rats with chronic unpredicted stress depression. Methods SD rats were randomly divided into blank group, model group, fluoxetine hydrochloride group, and Baishile Capsules high, medium, and low dose groups. Chronic stress depression rat model was established by chronic and mild unpredictable stressors. All groups were given relevant medicine for 21 days. The open-field test, sugar consumption experiment, place navigation test, and space searching experiment were used to detect behavior changes of the rats. ELISA was used to detect content of corticosterone in plasma. The protein expressions of PKA, BDNF, and CREB were detected by immunohistochemical method. Results Compared with model group, Baishile Capsules high dose and medium dose groups could remarkably increase the number of vertical and horizontal activities and 1% sucrose partial eclipse. Platform latency and target quadrant searching time decreased significantly in Baishile Capsules high dose group (P<0.05), and content of corticosterone in plasma increased obviously (P<0.05) in Baishile Capsules all dose groups. Protein expressions of PKA, CREB, and BDNF in hippocampal DG and CA3 area increased significantly (P<0.05) in Baishile Capsules high dose group. Conclusion Baishile Capsules can promote hippocampal neurogenesis through the cAMP-CREB-BDNF signal pathway and realize anti-depression effect.

Effect of Xiaoyao Powder on Alzheimer's disease in hippocampal CA3 region of rats PP-2A, GSK-3βexpression / 中国免疫学杂志

Objective:To study the effect of Xiaoyao Powder on Alzheimer's disease in hippocampal CA 3βregion of rats PP-2A,GSK-3βexpression.Methods:Rats were randomly divided into four groups , including model group, western medicine group,Chi-nese medicine group were treated with intraperitoneal injection of D-gal and A-β1-42 peptide bilateral hippocampal injection mold-ing, physiological group only with equal volume of sterile saline intraperitoneal and hippocampal injection molding .The model was completed, normal group, model group were perfused with saline , western medicine group and Chinese medicine group were treated with oxiracetam solution and Xiaoyao decoction , four groups of intragastric volume was 0.5 ml/100 g, 1 time a day, continuous 28 d. After intragastric administration of isolated rat brain immediately , packet marking in 4℃4%glutaraldehyde solution of glass container , stored at 4℃.Repair piece, cut from the hippocampus, embedded in paraffin, sliced.Dilution of PP-2A for 1∶200, GSK-3βdilution of 1∶150.Images were analyzed by using Image-pro Plus 5 image analysis system, data were conducted by SPSS11.5 statistical analysis software, the comparison between 4 groups by single factor analysis of variance , between the two two groups was compared by LSD-t test, the test level of α=0.05.Results:The expression of PP-2A positive cell number and the positive area , average optical density, integral optical density index , in Xiaoyao Powder orally intervention compared with the model group increased significantly (P<0.01);GSK-3βabove indices were significantly decreased than that in model group after Xiaoyao Powder after intragastric ad -ministration (P<0.01).Conclusion:Xiaoyao Powder can up regulate the expression of PP-2A and down regulate expression of GSK-3β, may be condensed A-β1-42 peptide induced hyperphosphorylation of Tau has certain inhibition .

Housing under the pyramid reduces susceptibility of hippocampal CA3 pyramidal neurons to prenatal stress in the developing rat offspring.

Mother-offspring interaction begins before birth. The foetus is particularly vulnerable to environmental insults and stress. The body responds by releasing excess of the stress hormone cortisol, which acts on glucocorticoid receptors. Hippocampus in the brain is rich in glucocorticoid receptors and therefore susceptible to stress. The stress effects are reduced when the animals are placed under a model wooden pyramid. The present study was to first explore the effects of prenatal restraint-stress on the plasma corticosterone levels and the dendritic arborisation of CA3 pyramidal neurons in the hippocampus of the offspring. Further, to test whether the pyramid environment would alter these effects, as housing under a pyramid is known to reduce the stress effects, pregnant Sprague Dawley rats were restrained for 9 h per day from gestation day 7 until parturition in a wire-mesh restrainer. Plasma corticosterone levels were found to be significantly increased. In addition, there was a significant reduction in the apical and the basal total dendritic branching points and intersections of the CA3 hippocampal pyramidal neurons. The results thus suggest that, housing in the pyramid dramatically reduces prenatal stress effects in rats.

The preventive and treatment effect of urtica dioica on astrocyte density in the CA1 and CA3 subfields of hippocampus in STZ induced diabetic rats / Efecto preventivo y del tratamiento de urtica dioica sobre la densidad de astrocitos en los subcampos CA1 y CA3 del hipocampo en ratas con diabetes inducida por STZ

Several animal model studies have shown that Diabetes mellitus can affect on the activity of hippocampus astrocytes, but these studies reported controversial findings. This study was done to evaluate the preventive and treatment effect of Urtica dioica (U. dioica) on astrocytes density in the CA1 and CA3 subfields of hippocampus of streptozotocin (STZ) induced diabetic rats. Twenty-eight male albino Wistar rats were randomly allocated equally into control, diabetic, U. dioica treatment and U. dioica preventive groups. Hyperglycemia was induced by STZ (80 mg/kg/BW). One week after injection of the streptozotocin, animals in treatment group were received hydroalcoholic extract of U. dioica (100 mg/kg/BW /day) for 4 weeks by intraperitoneally. In preventive group, diabetic rats were received 100 mg/kg/BW/ daily hydroalcoholic extract of U. dioica for 5 days before STZ injection. Then, animals were sacrificed and coronal sections were taken from the right dorsal hippocampus, stained with PTAH. The area densities of the astrocytes were measured. The number of astrocytes in CA1 of controls, diabetic treatment and preventive groups was 19.00+/-5.5, 17.14+/-6.4, 21+/-8.1 and 16.48+/-3.2, respectively. The densities of astrocytes in CA3 of controls, diabetic, treatment and preventive groups were 25.45+/-7.60, 21.54+/-7.5, 23.75+/-5.6 and 19.89+/-3.8, respectively. The density of astrocytes in diabetic rats reduced in comparison with controls (P<0.05). In CA1 and CA3, in spite of preventive administration, treatment of diabetic rats with U. dioica significantly increased the astrocytes. This study showed that treatment with U. dioica extract can help compensate for the CA1 and CA3 subfields of hippocampus astrocytes in diabetic rats.

Varios estudios en modelos animales han mostrado que la diabetes mellitus puede afectar la actividad de los astrocitos del hipocampo, pero estos resultados son controvertidos. Este estudio se realizó para evaluar el efecto preventivo y de tratamiento de la Urtica dioica (U. dioica) en la densidad de los astrocitos en los subcampos CA1 y CA3 del hipocampo en ratas diabéticas inducidas por estreptozotocina (STZ). Veintiocho ratas Wistar albinas macho fueron asignadas al azar por igual en grupos control, diabético, con tratamiento U. dioica y preventivo con U.dioica. La hiperglucemia se indujo por STZ (80 mg/kg/peso corporal). Una semana después, los animales del grupo tratamiento recibieron el extracto hidroalcohólico de U. dioica (100 mg/kg/peso corporal/día) durante 4 semanas vía intraperitoneal. El grupo preventivo, recibió 100 mg/kg/peso corporal/día de extracto hidroalcohólico U. dioica durante 5 días antes de la inyección de STZ. Los animales fueron sacrificados, se tomaron secciones coronales del hipocampo dorsal derecho y se tiñeron con PTAH. Fueron medidas las densidades de área de los astrocitos. El número de astrocitos en CA1 de los grupos de ratas control, diabéticas, con tratamiento de U. dioica y preventivo con U. dioica fue 19,00+/-5,5, 17,14+/-6,4, 21+/-8,1 y 16,48+/-3,2, respectivamente. Las densidades de los astrocitos en CA3 de los grupos de ratas control, diabéticas, con tratamiento de U. dioica y preventivo con U. dioica fue 25,45+/-7,60, 21,54+/-7,5, 23,75+/-5,6 y 19,89+/-3,8, respectivamente. La densidad de los astrocitos en las ratas diabéticas se redujo en comparación con los controles (P <0,05). En CA1 y CA3, a pesar de la administración preventiva, sólo el tratamiento de ratas diabéticas con U. dioica aumentó significativamente los astrocitos. Este estudio mostró que el tratamiento con extracto de U. dioica puede ayudar a compensar los astrocitos de los subcampos CA1 y CA3 del hipocampo en ratas diabéticas.

Epilepsia del lóbulo temporal y las neuronas hipocampales de las áreas CA1 y CA3 / Temporal lobe epilepsy and hippocampal neurons from areas CA1 and CA3

La epilepsia del lóbulo temporal es la forma más común de epilepsia que padece el ser humano. El sustrato fisiopatológico que la caracteriza es la esclerosis del hipocampo, que se distingue por pérdida neuronal, gliosis y disminución del volumen del hipocampo y áreas vecinas como la amígdala, el giro parahipocámpico y la corteza entorrinal. Lo anterior ocasiona atrofia y esclerosis del hilus del giro dentado y de las áreas CA1 y CA3 del hipocampo. Además se establece cierta reorganización de las vías neuronales que favorecen la neoespinogénesis, la morfogénesis, la neosinaptogénesis y la neurogénesis, con desarrollo aberrante de células y fibras, que contribuyen a la formación de un foco cuyo componente neuronal muestra un significativo aumento en la excitabilidad. El interés por entender el proceso de la epileptogénesis ha motivado al diseño de modelos de este tipo de epilepsia en animales de experimentación. La epileptogénesis evoluciona en el tiempo y muestra que la reorganización dinámica de las vías neuronales establece una red neuronal con cambios funcionales y anatómicos muy significativos. En este trabajo se realiza una revisión de la información obtenida por estudios electrofisiológicos que combinan el marcaje celular mediante el registro intra o extracelular en el hipocampo y en particular de las áreas CA1 y CA3 involucradas estrechamente con la epileptogénesis.

Temporal Lobe Epilepsy is the most common form of human epilepsy. Hippocampal sclerosis, neuronal loss, gliosis and hippocampal volume reduction are the representative changes of this pathology. Also some other near areas like amygdala, gyrus parahipocampal and entorrinal cortex are affected. Furthermore the neural circuits undergo activity-dependent reorganization during epileptogenesis. This brain circuits remodeling include neuronal loss (acute and delayed), neurogenesis, gliosis, plasticity (axonal and dendritic), inflammation and molecular reorganization. Two significant changes are evident, aberrant sprouting of granule cell axons in the dentate gyrus and hilar ectopic granular cells. Because temporal lobe epilepsy commonly develops after brain injury, most experimental animal models involve use of this factor. The pilocarpine-induced status epilepticus rat model may be the most widely used model of temporal lobe epilepsy. In the present work, we review the experimental support for seizure-induced plasticity in neural circuits, and then turn to evidence that seizure-induced plasticity occurs in human temporal-lobe.

Effect of Electroacupuncture on the Expression of Hippocampal Calbindin-D28K in Hyperlipemia Rats with Concurrent Cerebral Ischemia / 针刺研究

Objective To observe the effect of electroacupuncture(EA) on Calbindin D28K(CB) expression and apoptosis in hippocampus in hyperlipemia rats with concomitant cerebral ischemia(CI).Methods Forty male SD rats were rando-mized into control,hyperlipemia+CI(model),acupuncture Ⅰ,and acupuncture Ⅱ groups,with 10 cases in each.Hyperlipemia model was established by feeding the animals with high fat forage for 6 weeks and CI model established by occlusion of the unila-teral middle cerebral artery.For rats of acupuncture Ⅰ group,EA(1-3 mA,15 Hz) was applied to bilateral "Sanyinjiao"(SP 6) and "Fenglong"(ST 40) for 20 min every time,once daily for 10 days before CI.For rats of both acupuncture Ⅰ and Ⅱ groups,after CI,EA was applied to SP 6,ST 40,"Baihui"(GV 20) and "Shuigou"(GV 26) were punctured with filiform needles and stimulated by twirled the needle with hand continuously for 1 min,once daily for 7 days.The apoptotic cells of hippocampal CA 3 area were displayed by TUNEL(terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling) method.CB antibody staining with immunohistochemistry was used to show CB-positive cells which were observed by optic microscope.Results In comparison with control group,the percentage of apoptotic cells of the hippocampal CA 3 area in model group increased considerably(P

Modeling and simulating study on disorder of associative memory function of hippocampal CA3 region caused by synaptic deletion based on Hopfield-like spiking neural network model / 国际生物医学工程杂志

Objective A spiking Hopfield-like neural network was proposed and used to simulate the disorder of hippocampal associative memory disorder caused by synaptic deletion.Methods A three-layered Hopfield-like spiking neural network model with auto-associative memory function and hetero-associative memory function was proposed according to anatomical structure of hippocampal CA3,and both associative memories of the models were simulated under Matlab platform.Disorder of hippocampal associative memory was also simulated according to Ruppin's 'synaptic deletion' theory.Results With the increasing of synaptic deletion level,both associative memory functions impaired gradually.Conclusion Synaptic deletion of hippocampal CA3 region can lead to the disorder of autoassociative memory as well as heteroassociative memory.

Sex-dependent behavioral effects and morphological changes in the hippocampus after prenatal invasive interventions in rats: implications for animal models of schizophrenia

OBJECTIVES: Although schizophrenia affects both human genders, there are gender-dependent differences with respect to age of onset, clinical characteristics, course and prognosis of the disease. METHODS: To investigate sex-dependent differences in motor coordination and activity as well as in cognitive and social behavior, we repeatedly tested female (n = 14) and male (n = 12) Fisher rats (postnatal days, PD 56-174) that had received intracerebroventricular injections of kainic acid as well as female (n = 15) and male (n = 16) control animals. The hippocampus was examined histologically. RESULTS: Compared to male controls, in the alcove test both female controls and female animals with prenatal intervention spent less time in a dark box before entering an unknown illuminated area. Again, animals that received prenatal injection (particularly females) made more perseveration errors in the T-maze alternation task compared to controls. Female rats exhibited a higher degree of activity than males, suggesting these effects to be sex-dependent. Finally, animals that received prenatal intervention maintained longer lasting social contacts. Histological analyses showed pyramidal cells in the hippocampal area CA3 (in both hemispheres) of control animals to be longer than those found in treated animals. Sex-dependent differences were found in the left hippocampi of control animals and animals after prenatal intervention. CONCLUSION: These results demonstrate important differences between males and females in terms of weight gain, response to fear, working memory and social behavior. We also found sex-dependent differences in the lengths of hippocampal neurons. Further studies on larger sample sets with more detailed analyses of morphological changes are required to confirm our data.

Effect of Type I Collagen on Hydroxyapatite and Tricalcium Phosphate Mixtures in Rat Calvarial Bony Defects

To repair bone defects in the oral and maxillofacial field, bone grafts including autografts, allografts, and artificial bone are used in clinical dentistry despite several disadvantages. The purpose of this study was to evaluate new bone formation and healing in rat calvarial bone defects using hydroxyapatite (HA, Ca10[PO4]6[OH]2, Bongros(R), Bio@ Co., KOREA) and tricalcium phosphate (beta-TCP, Ca3[PO4]2, Sigma-Aldrich Co., USA) mixed at various ratios. Additionally, this study evaluated the effects of type I collagen (Rat tail, BD Biosciences Co., Sweden) as a basement membrane organic matrix. A total of twenty, 8-week-old, male Sprague-Dawley rats, weighing 250-300g, were divided equally into a control group (n=2) and nine experimental groups (n=2, each). Bilateral, standardized transosseous circular calvarial defects, 5.0 mm in diameter, were created. In each experimental group, the defect was filled with HA and TCP at a ratio of 100:0, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, and 0:100 with or without type I collagen. Rats were sacrificed 4 and 8 weeks post-operation for radiographic (standardized plain film, Kodak Co., USA), histomorphologic (H&E [Hematoxylin and Eosin], MT [Masson Trichrome]), immunohistochemical staining (for BMP-2, -4, VEGF, and vWF), and elementary analysis (Atomic absorption spectrophotometer, Perkin Elmer AAnalyst 100(R)). As the HA proportion increased, denser radiopacity was seen in most groups at 4 and 8 weeks. In general radiopacity in type I collagen groups was greater than the non-collagen groups, especially in the 100% HA group at 8 weeks. No new bone formation was seen in calvarial defects in any group at 4 weeks. Bridging bone formation from the defect margin was marked at 8 weeks in most type I collagen groups. Although immunohistochemical findings with BMP-2, -4, and VEGF were not significantly different, marked vWF immunoreactivity was present. vWF staining was especially strong in endothelial cells in newly formed bone margins in the 100:0, 80:20, and 70:30 ratio type I collagen groups at 8 weeks. The calcium compositions from the elementary analysis were not statistically significant. Many types of artificial bone have been used as bone graft materials, but most of them can only be applied as an inorganic material. This study confirmed improved bony regeneration by adding organic type I collagen to inorganic HA and TCP mixtures. Therefore, these new artificial bone graft materials, which are under strict storage and distribution systems, will be suggested to be available to clinical dentistry demands.

Effects of Chronic Cadmium Exposure on Learning,Memory and Hippocampus CA3 in Mice / 环境与健康杂志

Objective To study the learning and memory abilities together with the morphological changes in astrocyte and neuron in the hippocampal CA3 area in mice induced by chronic cadmium exposure. Methods Twenty Kunming mice aged 4-5 months were selected by Y-maze and randomly divided into two groups. The cadmium exposed group treated with cadmium (CdCl2,2 mg/kg) by subcutaneous injection,twice a week for 3 consecutive months,and the normal control group were injected with the equal dose of saline. The learning and memory abilities were detected by Y-maze after 3 months of treatment. The structure of astrocytes and neurons in CA3 area of hippocampus were observed under light microscope,and the quantitatively analysis was performed by cell morphometric technique. Results Compared with the control group,learning and memory capacity determined by Y-maze test in the cadmium exposed group were lower (P

The Effects of Unaggregated Amyloid ? Protein(25-35) on Transient Outward Potassium Current in Rat Hippocampal CA3 Pyramidal Neurons / 医学研究杂志

Objective To investigate the effects of unaggregated amyloid ? protein(A?25～35) on transient outward potassium channel(IA) in Rat Hippocampal CA3 Pyramidal Neurons.Methods Patch-clamp technique with whole cell recording was used.Results Unaggregated A?25～35 inhibited IA in neonatal rat hippocampal CA3 pyramidal neurons and displayed a time-,concentration- and voltage-dependent manner;the dynamic characteristics of IA were influenced:shifted the steady-state activation and inactivation curves to left significantly.Conclusion These results suggest that the inhibition of unaggregated A?25-35 on transient outward potassium channel in acutely isolated hippocampal CA3 pyramidal neurons may be an important mechanism of its toxicity,which participates in pathological changes of AD.

Effect of polyene phosphatidyl on synaptic plasticity in region of hippocampus CA3 of young rats / 吉林大学学报(医学版)

Objective To observe the structure changes of the synapse of the neurons in hippocampus CA3 of young rats and study the basis for the mechanism of polyene phosphatidyl in providing learning and memory and the effect on synaptic plasticity.Methods A total of 20 Wistar rats with 5 months were randomly divided into polyene phosphatidyl group and normal control group.Each group had 10 rats.After 4 weeks feeding,Water maze training was peformed in all the rats for 1 weeks.The immue expressions of synapsin(SYN) of the rats in polyene phosphatidyl group and control groups were observed with immunohistochemical method and analyzed by MOTAC imagine analyzing system.The change of synapse of hippocamal CA3 was observed with electron microscope.And the other 24 to 26 months rats were selected as aged group,and fed in the same condition.Moreover,the ultrastructures of hippocamal CA3 of aged rats were observed by transmission electron microscopy(TEM).Results The SYN in polyene phosphatidyl group(0.430 0?0.022 4) was higher than that in control group(0.3567?0.0209) (P

Loss of Parvalbumin Reactive Interneuron in Area CA3 of the Kainate-Treated Mouse Hippocampal Slice Culture / 대한소아신경학회지

PURPOSE: Loss of hippocampal interneurons in area CA3 has been reported in patients with severe temporal lobe epilepsy and in animals treated with kainic acid(KA). The effects of kainic acid on the survival of parvalbumin-immunoreactive(PARV-IR) interneurons in area CA3 were investigated in organotypic hippocampal slice cultures. METHODS: Cultured hippocampal slices from postnatal day 8-10 FVB mouse were exposed to 5 microM KA, and were analyzed at 0, 8, 24, 48, 72 hours after 1 hour KA exposure. Neuronal injury was determined by morphologic changes of PARV-IR interneuron in area CA3. RESULTS: Untreated cultures displayed an organotypic organization and morphology of PARV-IR interneurons in the hippocampus which paralelled those reported to occur in vivo. The reduction in numbers of PARV-IR interneurons in CA3 after transient(1 hour) exposure to 5 microM KA were similar to those reported to occur in CA1 after transient exposure to 10 microM. Parvalbumin-immunoreactivity transiently was reduced from the soma and dendrites of PARV-IR interneuron within 24 hours. Transient exposure of hippocampal slice cultures to KA produced marked focal swellings of the dendrites of PARV-IR interneurons. At 5 microM KA, more than 30% of the PARV-IR interneuron dendrites in area CA3 had a beaded appearance. The presence of focal swellings was reversible with KA washout and was not accompanied by interneuronal cell death. CONCLUSION: The results suggest that KA-induced cell death is delayed, therefore acute edema is insufficient to kill PARV-IR interneurons in area CA3.

A QUANTITATIVE INVESTIGATION ON SYNAPTIC STRUCTURAL PLASTICITY IN THE BRAIN OF MICE TREATED WITH DGAVP / 解剖学报

The changes of some parameters of Gray type Ⅰ synaptic interface in the brain of mice treated with desglycinamide-arginine-8-vasopressin (DGAVP) have been analysed quantitatively two hours after DGAVP injection. The animals were killed and the hippocampus and sensori-motor area of cerebral cortex were prepared for electron microscopy. The electron microphotographs were analysed by IBM-PC computer image processing system. The main results of the experiment are as follows:1. The thickness of postsynaptic density apparently increased in both the sensori-motor area of cerebral cortex and CA_3 area of hippocampus after injection of DGAVP (P