戊四氮诱发大鼠全身强直-阵挛性癫痫发作诱导终纹床核c-fos癌基因表达

本文用Fos癌蛋白抗体免疫组化法详细研究了戊四氮诱发大鼠全身强直-阵挛性癫痫发作诱导终纹床核c-fos癌基因表达的动态分布,结果如下:腹腔内注入戊四氮50mg/kg后0.5h,前腹区梭形核出现低密度的Fos免疫阳性(Fos-ir)细胞核标记;注射戊四氮后3h,前腹区和后部腹外侧区域均有较高密度的Fos-ir标记,前外区和前背区的密度则较低,后部背内侧区域未见Fos-ir标记;注射戊四氮后6h,终纹床核各核团和区域均出现较高密度的Fos-ir标记,其中,前部的密度高于后部、腹侧区域的密度高于背侧区域。上述终纹床核的Fos-ir标记出现的先后顺序及波及范围很可能反映了戊四氮诱发大鼠全身强直-阵挛性癫痫发作累及终纹床核的顺序和范围。     

SOMAN诱发惊厥大鼠丘脑内c－fos的表达

用ＡＢＣ免疫组化技术研究了Ｓｏｍａｎ诱发大鼠产生强直阵挛性惊厥后的ｃ－ｆｏｓ原癌基因在丘脑中的表达。结果显示：在低剂量Ｓｏｍａｎ中毒但未出现惊厥的动物和戊巴比妥抗惊厥的动物丘脑内都未见ｃ－ｆｏｓ表达的增加。而致惊厥的动物则从惊厥１ｈ至３ｈ，丘脑内ｃ－ｆｏｓ表达均有显著增加，表达呈恒定的核特异定位分布。出现群集ＦＯＳ样免疫阳性神经元的核团是：丘脑中线核群的丘脑室旁核、菱形核、粘合核；板内核群的中央旁核、中央内侧核和中央外侧核；丘脑前核诸亚核以及丘脑网状核。上述结果表明，丘脑非特异性核团的协同活动以及丘脑前核可能参与惊厥活动的整合。     

SOMAN诱发惊厥大鼠丘脑内c－fos的表达

用ＡＢＣ免疫组化技术研究了Ｓｏｍａｎ诱发大鼠产生强直阵挛性惊厥后的ｃ－ｆｏｓ原癌基因在丘脑中的表达。结果显示：在低剂量Ｓｏｍａｎ中毒但未出现惊厥的动物和戊巴比妥抗惊厥的动物丘脑内都未见ｃ－ｆｏｓ表达的增加。而致惊厥的动物则从惊厥１ｈ至３ｈ，丘脑内ｃ－ｆｏｓ表达均有显著增加，表达呈恒定的核特异定位分布。出现群集ＦＯＳ样免疫阳性神经元的核团是：丘脑中线核群的丘脑室旁核、菱形核、粘合核；板内核群的中央旁核、中央内侧核和中央外侧核；丘脑前核诸亚核以及丘脑网状核。上述结果表明，丘脑非特异性核团的协同活动以及丘脑前核可能参与惊厥活动的整合。     

大鼠间脑到前额叶皮质的传入投射——FG逆行追踪法

目的:探讨间脑中神经核向前额叶中央外侧区的投射.方法:用荧光金(FG)逆行追踪法对15只Wistar大鼠进行研究.结果:大鼠前额叶中央外侧区接受同侧丘脑前内侧核,丘脑前腹核;丘脑腹内侧核,丘脑腹外侧核,丘脑腹后内侧核,丘脑腹后外侧核;丘脑内侧背核中间部、外侧部、内侧部,丘脑外侧背核;丘脑后核,丘脑外侧后核;丘脑板内核的中央内侧核,中央旁核,中央外侧核,丘脑束旁核;丘脑中线核的丘脑带旁核,丘脑菱形核,丘脑连结核,丘脑室旁核;丘脑网状核,膝上核;下丘脑的室旁核,室周核,下丘脑后区,下丘脑外侧区,乳头体上核,乳头体内侧核.下丘脑外侧大细胞核,外侧视前区,内侧视前区及丘脑底部中的未定带,Forel区,丘脑底核的投射纤维.结论:前额叶中央外侧区接受广泛的间脑核团的投射,并存在着局部定位的关系.     

外周炎症性疼痛刺激诱导丘脑中胶质细胞激活及细胞因子的表达

目的:研究完全弗氏佐剂(CFA)外周刺激后,大鼠丘脑中线核群和板内核群中星形胶质细胞标记物(GFAP)、小胶质细胞标记物(Iba)以及细胞因子(IL-1β,TNF-α)的表达变化.方法:逆转录聚合酶链式反应(RT-PCR),免疫印迹法,免疫组织化学.结果:在炎症刺激后的4 h、3 d和14 d,丘脑中线核群和板内核群中小胶质细胞的标记物CD14、细胞因子IL-1β,TNF-α的mRNA和蛋白均有增加;星形胶质细胞标记物GFAP在炎症后的3 d和14 d,其mRNA和蛋白有显著增加.结论:外周炎症性刺激能够相继激活丘脑中线核群和板内核群的小胶质细胞和星形胶质细胞,并使炎症前细胞因子表达增多.提示该部位的胶质细胞可能通过细胞因子参与对炎症性疼痛的调节.     

大白鼠丘脑—纹状体投射——HRP法研究

大白鼠尾壳核注射HRP后,在丘脑板内核群中有较多的标记细胞,并有一定的定位关系。尾壳核头部背内侧注射HRP时,标记细胞主要在板内核的背侧部;尾壳核头部腹外侧注射HRP时,标记细胞主要在板内核的腹侧部。除板内核群外,丘脑腹前核、腹外侧核及腹内侧核均有较多纤维投射到尾壳核。丘脑背内侧核和前核群可能发出少量纤维投射到尾壳核。     

大鼠间脑到前额叶皮质的传入投射——FG逆行追踪法

目的：探讨间脑中神经核向前额叶中央外侧区的投射。方法：用荧光金（ＦＧ）逆行追踪法对１５只Ｗｉｓｔａｒ大鼠进行研究。结果：大鼠前额叶中央外侧区接受同侧丘脑前内侧核，丘脑前腹核；丘脑腹内侧核，丘脑腹外侧核，丘脑腹后内侧核，丘脑腹后外侧核；丘脑内侧背核中间部、外侧部、内侧部、丘脑外侧背核；丘脑后核，丘脑外侧一核；丘胲板内核的中央内核的中央内侧核，中央旁核，中央外侧核，丘脑束旁核；丘脑中线核的丘脑带旁核，     

NF1基因表达产物在大鼠脑的分布-免疫荧光组化法

用免疫荧光组织化学方法观察了 NF1基因表达产物神经纤维素在正常成年大鼠脑中的分布 ,结果如下 :(1)大脑皮质中神经纤维素阳性细胞最为密集 ;其次 ,在海马结构、丘脑前核群、丘脑内侧核群、丘脑板内核群、丘脑中线核群及下丘脑室周核、室旁核中神经纤维素阳性细胞也较密集 ;在杏仁核、下丘脑前区、下丘脑外侧区、下丘脑后区以及隔外侧核、隔内侧核、尾壳核、屏状核、苍白球、三叉神经脊束核等部位 ,也可见到数量不等的神经纤维素阳性细胞稀疏分布。 (2 )神经纤维素免疫阳性反应产物除了分布于神经细胞胞质外 ,在细胞核也有分布。 (3 )结合抗星形胶质细胞特异性酶 (胶质纤维酸性蛋白 )免疫组化反应 ,在星形胶质细胞中未观察到神经纤维素免疫反应阳性信号     

迷走神经刺激对戊四氮致痫大鼠丘脑网状核NMDAR1 mRNA和GABAARα1 mRNA的影响

为探讨迷走神经刺激（Vagus nerve stimulation,VNS)抗癫痫的作用机制。应用原位杂交组织化学及图像分析方法研究戊四氮（Pentylenetetrazol,PTZ)致痫大鼠丘脑网状核谷氨酸受体NMDAR1mRNA和γ-氨基丁酸A受体（GABAAR）α1亚单位mRNA的变化。结果显示，PTZ致痫组大鼠丘脑网状核NMDAR1mRNA表达明显高于正常对照组，而VNS抗癫痫组明显低于PTZ致癫痫组，与之相反，PTZ致癫痫组GABAARα1mRNA的表达明显低于正常对照组，VNS抗癫痫组明显高于PTZ致癫痫组，上述结果表明，VNS可能通过抑制丘脑网状核兴奋的神经递质受体NM-DAR的活动和增强抑制性神经递质受体γ-氨基丁酸受体GABAAR的活动，降低大脑皮层的兴奋性，抑制癫痫的发生和发展。     

大白鼠伏核的神经联系—HRP、WGA-HRP、荧光法研究

用HRP和荧光素—伊凡氏兰(EB)、核黄(NY)对大白鼠伏核的传入性联系,用WGAHRP对其传出性联系进行了实验研究。单纯HRP(19例)和荧光素EB(6例)、NY(4例)注入或泳入伏核后所产生的逆行标记结果基本一致。在丘脑,标记细胞大量出现于丘脑的带旁核、室周核、丘脑内侧核、板内核群;其它如连合核、菱形核和丘脑后内侧核也见到一些标记细胞。在中脑、黑质密带内侧份、被盖腹侧区有大量标记细胞。在边缘系统的海马、杏仁体有大量标记细胞,而内嗅区皮质和下脚仅在一些例中有明显的标记细胞。外例隔核、苍白球、尾壳核和丘脑下部等均未见标记。将WGA-HRP注入伏核内(7例),顺行性标记纤维主要经前脑内侧束下行。标记终支最明显的部位是腹侧苍白球、终纹床核和黑质网状带;其他如外侧隔核、下丘脑外侧核、丘脑底核和Forel H_2区、未定带、黑质密带等处也可见到少量的标记终支。     

The thalamus of the Amazon spiny rat Proechimys guyannensis,an animal model of resistance to epilepsy,and pilocarpine-induced long-term changes of protein expression

The thalamus of the spiny rat Proechimys guyannensis (casiragua), a common rodent of the Amazon basin, was investigated with immunohistochemistry, using as markers GABA and glutamic acid decarboxylase, and calcium binding proteins. As in all mammals, GABAergic neurons containing also parvalbumin filled the reticular nucleus, and GABAergic cells were seen in the dorsal lateral geniculate nucleus. At variance with the laboratory rat, GABAergic and parvalbumin-containing neurons were also seen in the laterodorsal and anterodorsal nuclei, in which the two markers were co-distributed. Calbindin-immunopositive cells were widely distributed in dorsal thalamic domains, except for the intralaminar nuclei, and prevailed in the laterodorsal nucleus. The distribution of calretinin-immunopositive neurons was more restricted, and they were especially concentrated in the laterodorsal and midline nuclei.At variance with the laboratory rat, in which systemic pilocarpine administration induces status epilepticus and results in chronic limbic epilepsy, pilocarpine elicited in casiragua an acute seizure that was not followed by spontaneous seizures up to 1 month, when changes were evaluated in the thalamus using also image analysis. Parvalbumin immunostaining in reticular nucleus neurons and in the dorsal thalamus neuropil, and the number of parvalbumin-positive and GABAergic cells in the laterodorsal and anterodorsal nuclei, exhibited an increase with respect to controls. Calbindin immunostaining was also enhanced, whereas calretinin immunostaining was mostly reduced, but was preserved in midline neurons. The findings show, after an acute seizure induced in an animal model of anti-convulsant mechanisms, regional long-term neurochemical alterations that could reflect functional changes in inhibitory and excitatory thalamic neurons.     

Calretinin distribution in the thalamus of the rat: immunohistochemical and in situ hybridization histochemical analyses.

The distribution of calretinin-containing cells was examined by in situ hybridization histochemistry and compared with the immunohistochemical mapping of calretinin in the thalamus of the rat. Results revealed a close correspondence between the immunohistochemical localization of cell bodies and the messenger RNA label produced by the calretinin oligonucleotide probe. Calretinin cells were most prominent in the midline (paraventricular, reuniens, rhomboid) and intralaminar (central medial, paracentral) nuclei and in a group of cells along the rostral central gray which appeared continuous with the caudal extent of the midline nuclei. A subpopulation of calretinin cell bodies was also identified in the reticular nucleus. The mediorostral lateral posterior nucleus, subparafascicular, lateral geniculate and habenular nuclei also contained calretinin messenger RNA probe label. In contrast, no positive cells were found in the anterior, ventral or posterior thalamic nuclei. The distribution of calretinin cells did not correspond directly with that of other histochemical markers. Thus, the in situ hybridization histochemical and immunohistochemical results revealed calretinin as a unique identifying marker for distinct sets of thalamic neurons.     

The pathways connecting the hippocampal formation, the thalamic reuniens nucleus and the thalamic reticular nucleus in the rat

Most dorsal thalamic nuclei send axons to specific areas of the neocortex and to specific sectors of the thalamic reticular nucleus; the neocortex then sends reciprocal connections back to the same thalamic nucleus, directly as well indirectly through a relay in the thalamic reticular nucleus. This can be regarded as a 'canonical' circuit of the sensory thalamus. For the pathways that link the thalamus and the hippocampal formation, only a few comparable connections have been described. The reuniens nucleus of the thalamus sends some of its major cortical efferents to the hippocampal formation. The present study shows that cells of the hippocampal formation as well as cells in the reuniens nucleus are retrogradely labelled following injections of horseradish peroxidase or fluoro-gold into the rostral part of the thalamic reticular nucleus in the rat. Within the hippocampal formation, labelled neurons were localized in the subiculum, predominantly on the ipsilateral side, with fewer neurons labelled contralaterally. Labelled neurons were seen in the hippocampal formation and nucleus reuniens only after injections made in the rostral thalamic reticular nucleus (1.6-1.8 mm caudal to bregma). In addition, the present study confirmed the presence of afferent connections to the rostral thalamic reticular nucleus from cortical (cingulate, orbital and infralimbic, retrosplenial and frontal), midline thalamic (paraventricular, anteromedial, centromedial and mediodorsal thalamic nuclei) and brainstem structures (substantia nigra pars reticularis, ventral tegmental area, periaqueductal grey, superior vestibular and pontine reticular nuclei). These results demonstrate a potential for the thalamo-hippocampal circuitry to influence the functional roles of the thalamic reticular nucleus, and show that thalamo-hippocampal connections resemble the circuitry that links the sensory thalamus and neocortex.     

Suprachiasmatic nucleus projections to the paraventricular thalamic nucleus of the rat

The suprachiasmatic nucleus (SCN) projections to the midline and intralaminar thalamic nuclei were examined in the rat. Stereotaxic injections of the retrograde tracer cholera toxin-β subunit (CTb) were made in 12 different thalamic sites. These included individual midline thalamic nuclei (anterior, middle, and posterior portions of the paraventricular thalamic nucleus (PVT), intermediodorsal, paratenial, rhomboid, or reuniens nuclei) and intralaminar thalamic nuclei (lateral parafascicular, central lateral, or central medial nuclei) as well as the mediodorsal and anteroventral thalamic nuclei. After 10–14 days survival, the brains from these animals were processed histochemically and the distribution of retrogradely-labeled neurons was mapped throughout the rostralcaudal extent of the SCN. Within this collective group of midline and intralaminar thalamic nuclei, the only region innervated by the SCN was the PVT. Approximately 80% of this projection arose from the dorsomedial SCN, and the remaining projection originated from the ventrolateral SCN which targeted mainly the anterior division of the PVT. Virtually no SCN neurons were labeled after CTb injections centered in any of the other midline thalamic nuclei, which includes the intermediodorsal, mediodorsal, paratenial, rhomboid, or reuniens thalamic nuclei. Similarly, no evidence for a SCN projection to the intralaminar thalamic nuclei was found. The discussion focuses on the role of SCN→PVT pathway in modulating cerebral cortical functions.     

Pattern of distribution of serotonergic fibers to the thalamus of the rat

It is well established that serotonergic (5-hydroxytryptamine, 5-HT) fibers, mainly originating from the dorsal and median raphe nuclei of the brainstem, distribute throughout the forebrain, most heavily to ‘limbic’ forebrain structures. Few reports have examined the distribution of 5-HT fibers to the thalamus and none to our knowledge using immunoprocedures for the detection of the serotonin transporter (SERT)—a very sensitive marker for 5-HT fibers. Using immunohistochemical methods for SERT, we examined the pattern of distribution of 5-HT fibers to the thalamus in the rat. We show that serotonergic fibers are heavily concentrated in midline, intralaminar and association nuclei of the thalamus, and with the exception of the lateral geniculate complex, weakly distributed to principal nuclei of thalamus. Specifically, we demonstrate that 5-HT fibers are densely concentrated in the anteroventral, anteromedial and interanteromedial nuclei of the anterior thalamus, the paraventricular, rhomboid and reuniens nuclei of the midline thalamus, the central medial and central lateral nuclei of the intralaminar thalamus, the intermediodorsal nucleus, the lateral dorsal nucleus, and the dorsal and ventral lateral geniculate nuclei and intergeniculate leaflet of the LGN complex. Less densely innervated sites include the mediodorsal, paracentral, parafascicular, lateral posterior and submedial nuclei of thalamus. Remaining regions of the thalamus, largely consisting of principal nuclei, contained few 5-HT fibers. This pattern of 5-HT innervation indicates that serotonin/serotonergic fibers mainly affect thalamic nuclei with connections to ‘non-principal’ or limbic regions of the cortex (or forebrain). This suggests that serotonergic fibers to the thalamus may exert a significant influence on affective and cognitive functions, possibly complementing the actions of 5-HT fibers to other parts of the brain involved in emotional and cognitive behaviors.