戊四氮点燃癫(癎)大鼠海马巢蛋白和骨形成蛋白-4的表达研究

目的观察巢蛋白(nestin)和骨形成蛋白4(BMP4)基因在戊四氮(PTZ)点燃癫大鼠海马中的表达,并探讨两者与癫发病机制的关系。方法将81只成年雄性SD大鼠随机分为实验组(n=54)和对照组(n=27)。实验组采用PTZ点燃癫大鼠,按点燃中的不同时相点,又随机分为9组。用免疫组化技术、地高辛标记特异性寡核苷酸探针原位杂交组织化学技术,观察海马nestin和BMP4表达的变化。结果nestin阳性细胞在PTZ注射后3d开始出现在齿状回、CA3区和CA1区,到7d达到高峰,以后逐渐减少。BMP4在PTZ注射后7d开始增多,在点燃后1d达到高峰,以后逐渐减少,主要分布在齿状回、CA3区和CA1区。结论PTZ点燃可引起海马内星形胶质细胞增生、活化和神经发生,这可能是癫海马组织胶质化、神经元可塑性的病理基础;BMP4可能在PTZ癫形成过程中起重要作用。     

Orexin受体拮抗剂对睡眠剥夺的戊四氮致(癎)大鼠癫(癎)发作及脑组织病理学变化的影响

目的 探讨orexin-1受体(OX1R)和orexin-2受体(OX2R)拮抗剂对睡眠剥夺(SD)的戊四氮(PTZ)致(癎)大鼠癫(癎)发作及脑组织病理学变化的影响.方法 雄性Wistar大鼠48只,随机分为正常对照(NC)组、PTZ组、SD+ PTZ( SD)组、SD+ PTZ+二甲基亚砜(DMSO)组、SD+ PTZ+ OX1R拮抗剂SB334867(SB)组和SD+ PTZ+ OX2R拮抗剂TCS OX229 (TCS)组.采用改良多平台SD法,SD前及SD 48 h分别给予相应组大鼠侧脑室注射DMSO、SB或TCS.SD 72 h给予各组腹腔注射PTZ 50 mg/kg诱导癫(癎)发作;观察各组大鼠癫(癎)发作的潜伏期、发作等级评分、发作持续时间及死亡率;应用常规染色法观察海马的病理学变化,免疫荧光法(BrdU标记)观察神经细胞增殖的变化.结果 (1)与PTZ组比较,SD组及DMSO组(癎)性发作的潜伏期明显缩短,发作等级评分、持续时间及死亡率明显增加(均P ＜0.001),海马CA3区神经元损害加重,海马齿状回门区和颗粒细胞下层BrdU阳性细胞数显著增多(P＜0.001);SD组与DMSO组间差异无统计学意义.(2)与SD组比较,SB组和TCS组大鼠(癎)性发作的潜伏期明显延长,发作等级评分、持续时间及死亡率明显下降(均P＜0.05),海马CA3区神经元损害明显减轻,齿状回门区和颗粒下层BrdU阳性细胞数减少(均P ＜0.05);TCS组的变化较SB组更显著(P＜0.05 ～0.01).结论 Orexin受体拮抗剂尤其是OX2R拮抗剂可通过减轻海马CA3区神经元的损害和抑制齿状回区细胞增殖减轻SD对PTZ诱导癫(癎)发作的不利影响.     

复智散对阿尔茨海默病大鼠海马内源性神经干细胞增殖的影响

目的观察复智散（FZS）对Alzheimer病（AD）模型大鼠海马齿状回内源性神经干细胞增殖的影响。方法采用β淀粉样蛋白25—35（Aβ25—35）侧脑室注射制作AD大鼠模型。采用Morris水迷宫检测大鼠的学习记忆能力,免疫荧光检测大鼠海马5-溴脱氧尿嘧啶（BrdU）阳性细胞表达,免疫组化检测海马增殖细胞核抗原（PCNA）阳性细胞表达,并对海马齿状回下颗粒层、海马门、分子层分别进行BrdU、PCNA阳性细胞计数。结果与模型组比较,健康对照组、假手术组和FZS治疗组大鼠水迷宫实验中的平均逃避潜伏期缩短（P〈0．05）,齿状回颗粒细胞下层BrdU、PCNA阳性细胞数量明显增加（P〈0．05）,但后三组之间比较差异无统计学意义。结论FZS可促进AD模型大鼠海马齿状回内源性神经干细胞增殖。     

行为学训练对海马损伤梗死大鼠齿状回区BrdU和Nestin表达的影响

目的 探讨行为学训练对海马损伤梗死大鼠齿状回区神经干细胞增殖的影响。方法 采用光化学法制成单侧海马损伤梗死模型大鼠72只,随机分为训练组（n=36）和自由活动组（n=36）,每个组设1、7、14、21、28及35d 6个亚组。另设正常对照组36只,与模型组对应分为1、7、14、21、28及35d 6个亚组。训练组大鼠于造模1d后给予水迷宫训练,自由活动组大鼠自由活动,不予水迷宫训练。免疫荧光双标记法观察各不同时间点大鼠海马齿状回区溴脱氧尿嘧啶核苷（Bromodeoxyuridine,BrdU）与巢蛋白（Nestin）的双标记表达情况。结果 正常对照组大鼠海马齿状回区有少量BrdU/Nestin双标记阳性细胞,训练组及自由活动组大鼠在7、14、21及28d海马损伤梗死侧齿状回区BrdU/Nestin双标记阳性细胞数量均有显著增多（P <0.01）;训练组大鼠7、14、21、28d时海马损伤梗死侧齿状回区的BrdU/Nestin双标记阳性细胞数量显著高于自由活动组（P <0.01）;至35d时,训练组及自由活动组大鼠海马损伤梗死侧齿状回区BrdU/Nestin双标记阳性细胞数量与正常对照组无明显差异（P >0.05）。结论 行为学训练能显著增强海马损伤梗死大鼠齿状回区神经干细胞的增殖,促进神经功能恢复。     

银杏叶提取物对点燃幼鼠学习记忆、神经元凋亡和神经发生的作用研究

目的 探讨银杏叶提取物(EGb)对癫痫点燃幼鼠学习记忆及神经元凋亡、神经发生的影响. 方法 选择21d日龄SD大鼠若干只,按照随机数字表法分为生理盐水组(NS)、点燃对照7d组(P-A7组)、点燃对照14d组(P-A14组)、EGb治疗7d组(P-E7组)、EGb治疗14d组(P-E14组),每组48只.应用戊四氮(PTZ)诱导点燃模型,Morris水迷宫检测大鼠学习记忆水平的变化,免疫组化法观察大鼠海马细胞凋亡、增殖情况,BrdU/神经元核抗原(NeuN)、BrdU/胶质纤维酸性蛋白(GFAP)荧光双标观察神经元分化的结果. 结果 (1)Morris水迷宫测试显示第4天时P-E7和P-E14组大鼠逃避潜伏期较NS组、P-A7组、P-A14组明显缩短,差异有统计学意义(P＜0.05)；靶象限活动时间百分比较P-A7组、P-A14组大鼠明显上升,跨越平台次数明显增多,差异有统计学意义(P＜0.05).(2)4组点燃大鼠海马CA3区TUNEL阳性细胞明显多于NS组,而P-E7和P-E14 2组大鼠凋亡细胞数较相应的P-A7、P-A14组明显减少,差异均有统计学意义(P＜0.05).(3)4组点燃大鼠海马CA1、CA3和DG区内巢蛋白(nestin)阳性细胞数量较NS组明显增多,差异有统计学意义(P＜0.05),其中尤以P-E7和P-E14组为著.大部分nestin阳性细胞向NeuN+细胞转化,BrdU/GFAP共表达率仅为4％～5％. 结论 EGb可以明显改善点燃幼鼠的学习记忆功能,推测机制为EGb的抗凋亡作用及诱导神经干细胞增殖、分化的作用.     

海马神经细胞活化在戊四氮点燃大鼠癫痫形成过程中的作用

目的 以核因子κB/P65(nuclear factor κB,NF-κB/P65)的核转位作为神经细胞活化的标志,观察在戊四氮(pentylenetetrazol,PTZ)点燃大鼠出现惊厥之前,即点燃过程中海马神经细胞NF-κB活化在癫痫形成过程中的作用.方法 将大鼠随机分为对照组、非药物干预组、药物干预组(苯巴比妥30 mg/kg, 腹腔注射,每日一次).除对照组外均以低于急性致惊剂量的PTZ(40mg/kg,腹腔注射,每日一次)点燃大鼠,用行为学观察和脑电图确定癫痫存在,免疫组织化学方法 检测大鼠癫痫形成过程中不同时间点海马CA各区和齿状回神经细胞NF-κB活化,用图像分析系统分析对照组、非药物干预组和药物干预组三大组间海马神经细胞NF-κB活化的差异.结果 非药物干预组大鼠均于17d～22d点燃,而药物干预组PTZ点燃大鼠所需时间明显延长(于30d～35d点燃),且行为学惊厥程度和脑电痫样放电明显轻于非药物干预组.非药物干预组大鼠在行为学未出现惊厥,脑电图未出现痫样放电的点燃前潜伏期内,其海马CA各区、齿状回NF-κB活化的阳性神经细胞数明显增加,与对照组相比两者有显著性差异(P<0.05);药物干预组在与非药物干预组相应时间点的海马CA各区、齿状回NF-κB活化的阳性神经细胞明显减少,两者有显著性差异(P<0.05).结论 海马神经细胞活化是PTZ点燃大鼠癫痫形成的重要机制之一,苯巴比妥可通过抑制神经细胞活化,预防癫痫发生.     

次声对成年大鼠齿状回神经前体细胞增殖的影响

目的研究次声对成年大鼠海马齿状回神经前体细胞增殖的影响。方法大鼠随机等分为正常对照组、假次声组和次声组（每组16只）。次声组暴露于8Hz、130dB次声环境7d（2h／d），暴露结束后第1、3、7、14d处死，采用抗5-溴脱氧尿嘧啶尿苷（BrdU）免疫组化方法，观察齿状回BrdU阳性细胞数的变化。结果次声作用结束后第1d，齿状回BrdU阳性细胞数与假次声组和正常对照组相比均无统计学差异；第3d及第7d，BrdU阳性细胞数减少（P〈0．05），第14d恢复正常水平。结论8Hz、130dB次声可抑制正常成年大鼠海马神经前体细胞增殖，可能与次声引起大鼠脑内微环境改变有关。     

发育期癫大鼠移植骨髓源性神经干细胞对海马BDNF和bFGF表达的影响

目的将骨髓源性神经干细胞(BMSCs)移植到发育期癫大鼠海马区,观察大鼠海马脑源性神经营养因子(BDNF)和碱性成纤维生长因子(bFGF)表达的变化。方法选择21日龄发育期大鼠,分离大鼠骨髓基质细胞,在特定条件下培养使其诱导分化为神经干细胞(NSC)。建立戊四氮(PTZ)点燃癫大鼠模型,将BMSCs经侧脑室注射移植至癫大鼠海马区;侧脑室注射磷酸缓冲液(PBS)作为对照。分为4组(均n=8):对照组(无癫发作),PTZ致组(癫造模,无治疗),假手术组(癫+PBS侧脑室注射),治疗组(癫+NSC侧脑室注射)。于3、7和14 d处理后用免疫组化法检测大鼠海马区BDNF和bFGF表达。结果致组大鼠海马区(齿状回、CA1区)BDNF和bFGF表达较对照组增加(P0.05),治疗组海马区(齿状回、CA1区)BDNF和bFGF表达较假手术组也有所增加(P0.05)。结论 BMSCs移植可以增加PTZ致大鼠海马BDNF和bFGF表达,从而发挥对癫后脑损伤的保护作用。     

柴胡总皂甙对戊四氮慢性点燃大鼠海马谷氨酸细胞的影响

目的研究柴胡总皂甙对戊四氮(PTZ)慢性点燃癫痫模型大鼠海马区谷氨酸(Glu)阳性细胞表达的影响。方法48只健康SD大鼠被随机分为6组,即空白组(A组)、生理盐水组(B组)、丙戊酸钠(VPA)组(C组)和柴胡总皂甙高、中、低三种剂量组(D组、E组、F组),每组8只,除A组不做处理外,其他各组采用腹腔注射PTZ慢性点燃造模,造模同时给予VPA、柴胡总皂甙等不同处理因素,连续4周后取脑组织切片进行Glu免疫组化染色,从阳性细胞数、灰度值分析结果。结果在CAl区,B组海马阳性细胞数高于A、C、D、E、F组,有显著性差异(P＜0．05),B组海马各区阳性细胞灰度值低于其他各组,与A、C、D各组比较,有显著性差异(P＜0．05)；而在CA2区和DG区,B组阳性细胞数、灰度值与各组差异无统计学意义。结论柴胡总皂甙可以影响PTZ点燃大鼠海马CA1区的Glu表达水平,从而抑制PTZ慢性点燃大鼠的痫性发作。     

Orexin受体拮抗剂对睡眠剥夺的戊四氮致疒间大鼠癫疒间发作及脑组织病理学变化的影响

目的探讨orexin-1受体(OX1R)和orexin-2受体(OX2R)拮抗剂对睡眠剥夺(SD)的戊四氮(PTZ)致疒间大鼠癫疒间发作及脑组织病理学变化的影响。方法雄性Wistar大鼠48只,随机分为正常对照(NC)组、PTZ组、SD+PTZ(SD)组、SD+PTZ+二甲基亚砜(DMSO)组、SD+PTZ+OX1R拮抗剂SB334867(SB)组和SD+PTZ+OX2R拮抗剂TCS OX229(TCS)组。采用改良多平台SD法,SD前及SD 48 h分别给予相应组大鼠侧脑室注射DMSO、SB或TCS。SD 72 h给予各组腹腔注射PTZ 50 mg/kg诱导癫疒间发作;观察各组大鼠癫疒间发作的潜伏期、发作等级评分、发作持续时间及死亡率;应用常规染色法观察海马的病理学变化,免疫荧光法(BrdU标记)观察神经细胞增殖的变化。结果 (1)与PTZ组比较,SD组及DMSO组疒间性发作的潜伏期明显缩短,发作等级评分、持续时间及死亡率明显增加(均P<0.001),海马CA3区神经元损害加重,海马齿状回门区和颗粒细胞下层BrdU阳性细胞数显著增多(P<0.001);SD组与DMSO组间差异无统计学意义。(2)与SD组比较...     

Dentate granule cell neurogenesis after seizures induced by pentylenetrazol in rats

Epileptic seizures originating from the limbic system have been shown to stimulate the proliferation rate of granule cell precursors in the adult brain, but it is not clear if other type(s) of seizures have the similar effects. This study examined the effects of pentylenetrazol (PTZ)-induced generalized clonic seizures on dentate granule cell neurogenesis in adult rats. Using systemic bromodeoxyuridine (BrdU) to label dividing cells, we studied the proliferation rate of neural precursor cells in the dentate gyrus at various time points after PTZ-induced seizures. The double-label immunofluorescence with confocal microscopy was used to determine the newborn cell phenotypes. Quantitative analysis of BrdU labeling revealed a significant increase in the proliferation rate of neural precursor cells in the dentate gyrus 3, 7, and 14 days after seizures. The number of BrdU-labeled cells in the dentate gyrus returned to baseline levels by 28 days after the initial seizures. Most of newborn cells migrated into the granule cell layer from the subgranular zone, displayed the neuronal phenotype, and developed morphological characteristics of differentiated dentate granule cells. These results indicated that neuron proliferation in the dentate gyrus was enhanced during a time window (3-14 days) after PTZ-induced seizures. Its underlying mechanism is discussed.     

慢性强迫游泳应激对大鼠海马神经元再生和p-CREB表达的影响

目的 研究慢性强迫游泳应激模型大鼠海马神经元再生和磷酸化环磷酸腺苷反应元件结合蛋白（p-CREB）的表达.方法 30只雄性SD大鼠随机分为3组：强迫游泳7 d组（S1组）、强迫游泳14 d组（S2组）和对照组.S1组和S2组分别连续强迫游泳7 d和14 d,每天5 min,水温（10±0.5）℃.采用免疫组化半定量测定大鼠海马5-溴脱氧尿苷（BrdU）和p-CREB阳性细胞表达情况.结果 免疫组化结果 显示,在整个海马结构中BrdU及p-CREB的阳性细胞主要集中于齿状回的颗粒细胞下层.与对照组比较,S1组、S2组大鼠海马齿状回BrdU和p-CREB阳性细胞数均明显减少（P＜0.01）;而与S1组比较,BrdU阳性细胞数无统计学差异（P＞0.05）,S2组p-CREB阳性细胞数进一步减少（P＜0.01）.结论 慢性强迫游泳应激可导致海马神经元再生功能障碍,其机制可能与p-CREB信号转导通路有关. 基金项目：     

戊四氮点燃癫癎大鼠海马5-羟色胺能神经递质的动态研究

目的：观察戊四氮（PTZ）点燃癫癎形成过程中大鼠海马5-羟色胺（5-HT）能神经递质的变化。方法：用PTZ制作癫癎大鼠模型,将造模成功大鼠分为戊四氮急性发作组（PTZ 1组）和戊四氮慢性点燃组（PTZ 2组）,同时设立对照组（腹腔注射生理盐水）。在体微透析取样,观察大鼠行为、脑电图（EEG）和海马5-HT能神经递质的变化。结果：PTZ 1组癫癎发作时EEG自发放电逐级加重;癫癎发作时海马5-HT水平与对照组、发作前和发作后比较显著升高（P〈0.05）;海马5-羟吲哚乙酸（5-HIAA）水平差异无统计学意义;5-HT转化率（5-HIAA/5-HT）降低,差异有统计学意义（P〈0.05）。PTZ 2组点燃后大鼠出现自发癫癎发作,EEG在发作间期出现自发放电;5-HT和5-HIAA水平在点燃期、维持点燃期、对照组间比较差异有统计学意义（P〈0.05）。结论：大鼠癫癎发作时海马5-HT水平显著升高,发作后恢复正常;在癫癎形成过程中,早期5-HT水平一过性升高、PTZ点燃后和发作间期海马5-HT水平逐渐降低。     

Response of seizure-induced newborn neurons in the dentate gyrus of adult rats to second episode of seizures

In this study we examined the unknown issue of whether seizure-induced newborn hippocampal neurons in freely moving adult rats are able to respond to pathophysiological stimuli in the same way as their neighboring neurons do. Three days after pentylenetrazol (PTZ)-induced generalized seizures, rats received 5-bromodeoxyuridine (BrdU) injections to label dividing cells, followed 4 weeks later by the second PTZ injection to induce second episode of generalized seizures. We observed that the first episode of PTZ-induced seizures resulted in a significant increase in the number of newborn neurons in the adult hippocampal dentate gyrus. In comparison with vehicle-injected control rats that exhibited no Fos immunoreactivity and mild glutamic acid decarboxylase 67 (GAD67) expression in the dentate granule cells, rats killed 2-6 h following the second PTZ injection showed intensive Fos and GAD67 expression in virtually all granule cells with or without BrdU double-labeling. These findings provide important evidence indicating that seizure-induced newborn neurons in freely moving adult rats are able to respond to pathophysiological stimuli in the same way as neighboring neurons do.     

Ionizing radiation-induced apoptosis of proliferating stem cells in the dentate gyrus of the adult rat hippocampus.

The occurrence of radiation-induced apoptosis in normal brain was investigated using an animal model of radiosurgery. Adult male Fischer rats aged 3 to 4 months were subjected to single dose convergent beam irradiation (10 Gy). Apoptotic cell death was determined by in situ labeling of DNA nick ends (TUNEL) and light microscopic evaluation of cell morphology. Five hours after irradiation, a highly significant increase of apoptotic cells in the subgranular zone of the dentate gyrus was paralleled by a corresponding significant decrease of cells immunoreactive for the proliferation marker Ki-67. Morphology, location and distribution of cells affected by radiation-induced apoptosis in the dentate gyrus subgranular zone, together with NeuN-immunohistochemistry, support the contention that these cells belong to the immature progenitor population responsible for neurogenesis in the adult rat hippocampus.     

Granule cell dispersion and aberrant neurogenesis in the adult hippocampus of an LIS1 mutant mouse

Human type 1 lissencephaly is a severe brain malformation associated with cognitive dysfunction and intractable epilepsy. Mutant mice with a heterozygous deletion of LIS1 show varying degrees of hippocampal abnormality and enhanced excitability. Whether a reduction of LIS1 function affects adult hippocampal neurogenesis, and if so, whether aberrant neurogenesis contributes to the generation of a disorganized hippocampus remain unknown. Previous reports indicate the presence of multiple pyramidal cell layers and granule cell dispersion in LIS1 mutant mice. Here we observed disruption of the subgranular zone and glial fibrillary acidic protein-immunoreactive radial astrocytes in the dentate gyrus of adult LIS1 mice. Using pulse-chase bromodeoxyuridine (BrdU) labeling combined with neuronal and glial antibody staining we provide evidence for ectopic adult neurogenesis in LIS1 mice. A gradually decreased survival rate for these newborn granule cells was also demonstrated in LIS1 mice 7 days after BrdU injection. This reduced survival rate was associated with impaired neuronal differentiation 28 days after BrdU administration. Thus, LIS1 haploinsufficiency can lead to abnormal cell proliferation, migration and differentiation in the adult dentate gyrus.     

Hippocampal plasticity after a vagus nerve injury in the rat

Stimulation of the vagus nerve has been previously reported to promote neural plasticity and neurogenesis in the brain. Several studies also revealed plastic changes in the spinal cord after injuries to somatosensory nerves originating from both the brachial and lumbo-sacral plexuses. However, the neurogenic responses of the brain to the injury of the viscerosensory innervation are not as yet well understood. In the present study, we investigated whether cells in the dentate gyrus of the hippocampus respond to a chemical and physical damage to the vagus nerve in the adult rat. Intraperitoneal capsaicin administration was used to damage non-myelinated vagal afferents while subdiaphragmatic vagotomy was used to damage both the myelinated and non-myelinated vagal afferents. The 5-bromo-2-deoxyuridine (BrdU) incorporation together with cell-specific markers was used to study neural proliferation in subgranular zone, granule cell layer, molecular layer and hilus of the dentate gyrus. Microglia activation was determined by quantifying changes in the intensity of fluorescent staining with a primary antibody against ionizing calcium adapter-binding molecule 1. Results revealed that vagotomy decreased BrdU incorporation in the hilus 15 days after injury compared to the capsaicin group. Capsaicin administration decreased BrdU incorporation in the granular cell layer 60 days after the treatment. Capsaicin decreased the number of doublecortin-expressing cells in the dentate gyrus, whereas vagotomy did not alter the expression of doublecortin in the hippocampus. Both the capsaicinand the vagotomy-induced damage to the vagus nerve decreased microglia activation in the hippocampus at 15 days after the injury. At 30 days post injury, capsaicin-treated and vagotomized rats revealed significantly more activated microglia. Our findings show that damage to the subdiaphragmatic vagus in adult rats is followed by microglia activation and long-lasting changes in the dentate gyrus, leading to alteration of neurogenesis.     

Noggin参与海人酸损伤后成年大鼠海马颗粒下区颗粒细胞增殖

目的 探讨侧脑室注射海人酸(KA)致大鼠海马损伤后Noggin的表达变化及其与颗粒细胞增殖的关系.方法 健康雄性SD大鼠32只采用随机数字表法分为实验组(16只)及对照组(16只).对照组又分为生理盐水对照组和空白对照组,各8只.实验组大鼠侧脑室注射KA,生理盐水对照组注射等剂量生理盐水.空白对照组不作处理.侧脑室注射KA 1周内,尼氏染色检测海马神经元的丢失.免疫荧光染色与原位杂交的方法检测海马齿状回BrdU标记细胞与Noggin mRNA阳性细胞的变化.结果 在侧脑室注射KA致海马损伤后1周,海马CA3、CA4区神经元丢失明显.与生理盐水对照组比较,实验组海马齿状回BrdU阳性细胞升高,差异有统计学意义(P=0.006),其中注射侧较对侧更为明显.海马Noggin mRNA阳性细胞在第3天时升高,第7天时下降.结论 侧脑室注射KA致海马损伤后.成年大鼠海马齿状回颗粒细胞异常增殖可能与Noggin表达波动有关.     

The fate of neural progenitor cells expressing astrocytic and radial glial markers in the postnatal rat dentate gyrus

In the dentate gyrus neurons continue to be generated from late embryonic to adult stage. Recent extensive studies have unveiled several key aspects of the adult neurogenesis, but only few attempts have so far been made on the analysis of the early postnatal neurogenenesis, a transition state between the embryonic and adult neurogenesis. Here, we focus on the early postnatal neurogenesis and examine the nature and development of neural progenitor cells in Wistar rats. Immunohistochemistry for Ki67, a cell cycle marker, and 5-bromo-2-deoxyuridine (BrdU) labelling show that cell proliferation occurs mainly in the hilus and partly in the subgranular zone. A majority of the proliferating cells express S100beta and astrocyte-specific glutamate transporter (GLAST) and the subpopulation are also positive for glial fibrillary acidic protein (GFAP) and nestin. Tracing with BrdU and our modified retrovirus vector carrying enhanced green fluorescent protein (GFP) indicate that a substantial population of the proliferating cells differentiate into proliferative neuroblasts and immature neurons in the hilus, which then migrate to the granule cell layer (66.8%), leaving a long axon-like process behind in the hilus, and the others mainly become star-shaped astrocytes (12.0%) and radial glia-like cells (4.7%) in the subgranular zone. These results suggest that the progenitors of the granule cells expressing astrocytic and radial glial markers, proliferate and differentiate into neurons mainly in the hilus during the early postnatal period.