听源性惊厥点燃后听党内核团和前脑结构内一氧化氮合酶阳性神 …

为探讨一氧化氮在听源性惊厥点燃中的作用，用ＮＡＤＰＨ－ｄ组织化学方法和体视学分析，了Ｗｉｓｔａｒ种系的听源性惊厥易感大鼠惊厥和点燃听觉核团内ＮＯＳ阳性神经元的分布及差异。     

听源性惊厥点燃诱导一氧化氮合酶表达增加

为探讨一氧化氮在听源性惊厥点燃中的可能作用，用ＮＡＤＰＨ－黄递酶组织化学方法和Ｆｏｓ免疫细胞化学方法，研究了听源性惊厥易感大鼠惊厥和点燃后听觉核团和前脑结构内ＮＯＳ－Ｆｏｓ双重阳性神经元的分布及差异。结果显示：一次惊厥后，正丘内双重阳性神经元较较多，近７０％－８０％的ＮＯＳ阳性神经元呈Ｆｏｓ阳性，其他听觉核团和内仅见少星ＮＯＳ－Ｆｏｓ双重阳性神经元。点燃后，听觉核团和前脑结构内ＮＯＳ－Ｆｏｓ双得阳     

听源性惊厥易感大鼠惊厥和点燃后听觉核团内的c—fos表达

为探讨听源性惊厥点燃和听觉核团的关系，用免疫细胞化学方法结合体视学分析，研究了Ｗｉｓｔａｒ种系的听源性惊厥易感大鼠惊厥和点燃后听觉核团内ｃ－ｆｏｓ表达的差异。在内侧膝状体背侧核和蜗神经背核，Ｆｏｓ标记细胞无显著变化。本研究结果表明，听源性惊厥导的display status     

听源性惊厥点燃后听觉核团和前脑结构内一氧化氮合酶阳性神经元的形态学观察

为探讨一氧化氮在听源性惊厥点燃中的作用．用NADPH-d组织比学方法和体视学分析,研究厂Wistar种系的听源性惊厥易感大鼠（P77PMC）惊厥和点燃后听觉核团内NOS阳性神经元的分布及差异。结果显示：（1）P77PMC大鼠一次惊厥后,听觉核团和前脑结构内可见广泛的NOS阳性神经元,其分布类似于正常大鼠;（2）点燃后,听觉核团和前脑结构内NOS染色增深,NOS阳性神经元增加。特别是在下丘和嗅周皮质．除NOS阳性神经元明显增多外．其分布亦发生改变。本研究提示,听源性惊厥可诱导NOS表达增加,这种增加可能对于保持神经元增高的易感性有关。     

听源性惊厥点燃诱导海马结构神经细胞死亡

目的　检测听源性惊厥单次发作及惊厥点燃发作后 ,易感大鼠海马结构内是否出现神经细胞死亡现象 ,并对细胞死亡的相关机制进行初步分析。　方法　建立听源性惊厥点燃模型 ,以HE染色和免疫细胞化学染色方法 ,检测单次发作大鼠和点燃发作大鼠海马结构内死亡细胞的分布 ,以及凋亡相关蛋白Bcl 2和Bax的表达情况。　结果　听源性惊厥单次发作后 ,海马内未见明显细胞死亡现象 ;点燃后 ,海马CA1 、CA2 、CA4 区锥体细胞层及齿状回颗粒细胞层出现大量核固缩、胞浆嗜酸性变的死亡神经元 ;点燃组海马CA2 区及CA4 区内Bax免疫阳性产物校正光密度 (CA)值较对照组显著增高。　结论　听源性惊厥点燃可诱导海马结构大量神经元死亡 ,凋亡可能是细胞死亡的形式之一     

听源性惊厥易感大鼠点燃后海马结构内的突触素表达

为探讨听源性惊厥点燃对突触可塑性的影响，采用免疫细胞化学方法结合体视学分析，研究了Ｗｉｓｔａｒ种系的听源性惊厥易感大鼠（Ｐ７７ＰＭＣ）惊厥和点燃后海马结构内突触素ｐ３８表达的差异。结果显示：（１）Ｐ７７ＰＭＣ大鼠１次惊厥后，海马结构内ｐ３８免疫反应产物呈明显的板层样分布；（２）Ｐ７７ＰＭＣ大鼠点燃后，ｐ３８免疫反应产物的定位分布与１次惊厥后相比较，没有明显改变，但是，ｐ３８免疫反应产物的密度普遍增     

听源性惊厥点燃诱导新皮质内c-fos和BDNF变化的研究

为探讨前脑结构参与听源性惊厥点燃过程的神经化学机制 ,本研究以 c-fos基因表达作为神经元功能活动的标志 ,采用免疫细胞化学方法 ,对新皮质内参与听源性惊厥点燃过程的神经元的分布状况进行了观察 ,并对相关区域内脑源性神经营养因子表达水平的变化进行了分析。结果显示 ,单次听源性惊厥发作后 ,新皮质内仅有少量散在的 c-fos阳性神经元存在 ;听源性惊厥点燃后 ,额、顶、枕及颞叶皮质内出现大量 c-fos阳性神经元。点燃后额叶及顶叶皮质内脑源性神经营养因子免疫阳性产物的校正光密度值显著增高。结果表明 ,新皮质内大量神经元参与听源性惊厥点燃过程 ,脑源性神经营养因子表达增强很可能是其中的机制之一。     

听源性惊厥易感大鼠中脑导水管周围灰质内突触素的表达

目的 分析正常及点燃后听源性惊厥易感大鼠中脑导水管周围灰质（ＰＡＧ）内突触密度的变化情况。方法 用免疫细胞化学方法和计算机图像分析技术。结果 正常和点燃后听源性惊厥易感大鼠ＰＡＧ内突触素Ｐ３８凤应产物的校正光密度值（ＣＯＤ）均显著高于正常Ｗｉｓｔａｒ大鼠;点燃后听源性惊厥易感大鼠ＰＡＧ背侧及背外侧两个亚区内突触素Ｐ３８免疫反应产物的ＣＯＤ去值显著高于正常听源性惊厥易感大鼠。     

听源性惊厥发作后中脑导水管周围灰质内c-fos基因的变化

目的 探讨中脑导水管周围灰质（ＰＡＧ）与听源性惊厥的关系。方法 用神经细胞Ｚ（Ｎｉｓｓｌ）染色和免疫细胞化学技术,观察听源性惊厥发作后易感大鼠（Ｐ７７ＰＭＣ）ＰＡＧ内即早基因ｃ－ｆｏｓ的表达情况。结果 听源性惊厥发作２ｈ后,Ｐ７７ＰＭＣ大鼠ＰＡＧ的背侧亚区及背外侧亚区,尾侧段腹外侧亚区内出现大量Ｆｏｓ阳性神经元,Ｆｏｓ阳性神经元百分率显著高于对照组。     

听源性惊厥易感性大鼠上丘一氧化氮合酶阳性神经成分的分布

用还原性烟酰胺腺嘌呤二核苷酸磷酸黄递酶，简称黄递酶（ＮＡＤＰＨ－ｄ）组织化学的方法，在光镜下对ＮＡＤＰＨ－ｄ反应阳性细胞进行计数和计算机图像分析测定反应产物的光密度（ＯＤ）值，观察一氧化氮合酶（ＮＯＳ）阳性神经元及纤维在惊厥鼠上丘分布的情况。实验动物为听源性惊厥易感性大鼠，简称惊厥鼠（Ｐ７７ＰＭＣ）和正常Ｗｉｓｔａｒ大鼠，简称正常鼠。实验结果如下：（１）在大鼠上丘第Ⅱ层ＮＯＳ阳性神经元呈密集均匀分     

听源性惊厥易感大鼠点燃后海马结构内生长相关蛋白的表达

用免疫细胞化学方法结合体视学分析，研究了Wistar大鼠的听源性惊厥易感大鼠（P77PMC）惊厥和点燃后海马结构内生长相关蛋白表达的差异、结果显示：（1）P77PMC大鼠一次惊厥后，海马结构内有广泛的生长相关蛋白免疫反应产物沉积，其分布呈板层样；（2）P77PMC大鼠点燃后，生长相关蛋白免疫反应产物的分布特征与一次惊厥后相比较，无明显变化，但是，海马CA3区苔藓纤维层生长相关蛋白免疫反应产物的光密度值显著增加（P＜0．01）。结果表明，听源性惊厥点燃能够诱导海马结构内生长相关蛋白表达增加。本文还对生长相关蛋白表达增加的生物学意义进行了讨论．     

Interruption of supramammillohippocampal afferents prevents the genesis and spread of limbic seizures in the hippocampus via a disinhibition mechanism

In this study we describe the preventive effect of interruption of the supramammillohippocampal afferents on the Fos expression in the forebrain and epileptic discharges in the hippocampal electroencephalogram in rat model of kainic acid-induced limbic seizure. Little was known about the contribution of different degrees of neural activity of hippocampal principal cells to the genesis and spread of limbic seizures in the forebrain structures. Following kainic acid injection to the amygdala with or without concurrent injection of muscimol to the supramammillary nucleus, behavioral changes and electroencephalograms were observed in freely moving rats. The animals were processed for Fos immunocytochemical analysis at several time points. The latest expression of Fos at 2h was seen in hippocampal CA1-CA3, ventrolateral thalamic nuclei and mediodorsal caudate putamen, while the early Fos expression at 0.5h was seen in the piriform, entorhinal and other cortices, the thalamic midline nuclei and hypothalamic nuclei. Muscimol injection to the supramammillary nucleus prevented Fos expression in the CA1-CA3 region and reduced that in the forebrain regions with the latest Fos expression, but did not affect Fos expression in other forebrain regions with early Fos expression. This treatment also eliminated epileptic discharges and attenuated all waves in hippocampus.These findings indicate that an acute interruption of the facilitatory hypothalamic afferents by intrasupramammillary injection of muscimol may cause the inactivation of the disinhibition mechanism for hippocampal throughput at the dentate gyrus, resulting in the blockade of the genesis and spread of limbic seizures in the hippocampus.     

马桑内酯致痫大鼠海马内c－fos原癌基因表达及谷氨酸免疫反应的变化

用免疫细胞化学双重染色法对马桑内酯致痫大鼠齿状回及海马回ＣＡ３区内原癌基因表达、谷氨酸免疫反应的变化及其相互关系进行了研究。一侧侧脑室内注射马桑内酯诱发癫痫后，在双重免疫细胞化学染色的切片上，齿状回及海马回ＣＡ３区内均有３种不同类型的细胞：谷氨酸（Ｇｌｕ）单标细胞、Ｆｏｓ单标细胞和Ｆｏｓ／Ｇｌｕ双标细胞。癫痫发作后１ｈ，注射侧齿状回有大量Ｆｏｓ／Ｇｌｕ双标细胞，而海马回ＣＡ３区仅有散在的双标细胞；癫痫发作后１．５ｈ，海马回ＣＡ３区双标细胞数明显增多。Ｆｏｓ单标细胞数及谷氨酸免疫反应性与双标细胞数是平行的。根据以上结果，本文对马桑内酯致痫的机制进行了讨论。     

Hippocampal cell proliferation and epileptogenesis after audiogenic kindling are not accompanied by mossy fiber sprouting or Fluoro-Jade staining

Repetitive sound-induced seizures, known as audiogenic kindling (AK), gradually induce the transference of epileptic activity from brainstem to forebrain structures along with behavioral changes. The aim of our work was to correlate the behavioral changes observed during the AK with possible alterations in neuronal proliferation, cell death, hippocampal mossy fiber sprouting and in the EEG pattern of Wistar audiogenic rats, a genetically susceptible strain from our laboratory.Susceptible and non-susceptible animals were submitted to repeated sound stimulations for 14-16 days and hippocampal mitotic activity was studied through the incorporation of bromodeoxyuridine (BrdU). Cell death and mossy fiber sprouting were assessed, respectively, by using Fluoro-Jade and Timm staining, 2 and 32 days after the last kindling stimulation. In addition, we used immunofluorescent double labeling for a glial and a mitotic marker to evaluate newly born cell identity. Some animals had hippocampus and amygdala electrodes for EEG recordings.Our results show that kindled animals with 6-11 generalized limbic seizures (class IV-V) had increased cell proliferation in the dentate gyrus when compared with animals with zero or one to three seizures. BrdU-positive cells labeled on day 2 and on day 32 were both GFAP negative. In the later group, rounded and well-defined BrdU-positive/GFAP-negative nuclei were seen in different portions of the granule cell layer. We did not observe any Fluoro-Jade or differential Timm staining in kindled animals at both killing times. However, EEG recordings showed intense epileptic activity in the hippocampus and amygdala of all animals with limbic seizures.Therefore, our data indicate that AK-induced limbic epileptogenicity is able to increase the hippocampal mitotic rate, even though it does not seem to promote neuronal death or mossy fiber sprouting in the supragranular layer of the dentate gyrus.     

Limbic epileptogenicity, cell loss and axonal reorganization induced by audiogenic and amygdala kindling in wistar audiogenic rats (WAR strain)

Audiogenic seizures are a model of generalized tonic-clonic brainstem-generated seizures. Repeated induction of audiogenic seizures, in audiogenic kindling (AuK) protocols, generates limbic epileptogenic activity. The present work evaluated associations between permanence of AuK-induced limbic epileptogenicity and changes in cell number/gluzinergic terminal reorganization in limbic structures in Wistar audiogenic rats (WARs). Additionally, we evaluated histological changes after only amygdala kindling (AmK) and only AuK, and longevity of permanence of AuK-induced limbic epileptogenicity, up to 160 days. WARs and Wistar non-susceptible rats were submitted to AuK (80 stimuli) followed by both 50 days without acoustic stimulation and AmK (16 stimuli), only AmK and only AuK. Cell counting and gluzinergic terminal reorganization were assessed, respectively, by using Nissl and neo-Timm histochemistries, 24 h after the last AmK stimulus. Evaluation of behavioral response to a single acoustic stimulus after AuK and up to 160 days without acoustic stimulation was done in another group. AuK-induced limbic epileptogenicity developed in parallel with a decrease in brainstem-type seizure severity during AuK. AmK was facilitated after AuK. Permanence of AuK-induced limbic epileptogenicity was associated with cell loss only in the rostral lateral nucleus of amygdala. Roughly 20 generalized limbic seizures induced by AuK were neither associated with hippocampal cell loss nor mossy fiber sprouting (MFS). AmK developed with cell loss in hippocampal and amygdala nuclei but not MFS. Main changes of gluzinergic terminals after kindling protocols were observed in amygdala, perirhinal and piriform cortices. AuK and AuK-AmK induced a similar number and type of seizures, higher than in AmK. AmK and AuK-AmK were associated with broader cell loss than AuK. Data indicate that permanent AuK-induced limbic epileptogenicity is mainly associated to gluzinergic terminal reorganization in amygdala but not in the hippocampus and with no hippocampal cell loss. Few AmK-induced seizures are associated to broader and higher cell loss than a higher number of AuK-induced seizures.