Comparative Analysis of the Frequency of Neuron Spike Activity in the Sensorimotor Cortex of the Right and Left Hemispheres in Conditions of Immobilization Catatonia in Rabbits

Multineuron activity was recorded from the sensorimotor cortex of the right and left hemispheres during immobilization catatonia in rabbits. The first session of immobilization of the animals was followed by changes in spike frequency in 47% of neurons in the sensorimotor cortex of the right hemisphere. Of these, 30% showed decreases in spike frequency and 17% showed increases. Spike frequency in the sensorimotor cortex of the left hemisphere changed in only 18% of cells, of which 13% showed decreases in spike frequency and 5% showed increases. The spike frequency of neighboring (recorded with the same electrode) neurons could change reciprocally. Differences in neuron activity in the two hemispheres were virtually absent after the second session of immobilization (several days after the first) – spike activity changed in 21% of neurons in the right hemisphere and 24% in the left hemisphere. The ratios of the numbers of neurons with increases and decreases in spike activity in hypnosis also became identical in the cortex of the right and left hemispheres. A hypothesis is proposed for the involvement of cortical neurons in the organization of hypnosis-like states.     

大鼠孤束核内5-HT能纤维和终末与向臂旁核投射的NOS阳性神经元的联系

应用四甲基罗达明逆行标记和免疫荧光技术相结合 ,在激光扫描共聚焦显微镜下对大鼠孤束核内 5 -HT能纤维和终末与向臂旁核投射的 NOS阳性神经元之间的联系进行了观察。将四甲基罗达明注入一侧外侧臂旁核后可见孤束核尾段背内侧、胶质、小细胞、内侧、中间内侧等亚核和连合亚核内出现较多的逆标神经元 ,四甲基罗达明逆标和 NOS阳性神经元以及 5 -HT阳性终末重叠分布 ,其中四甲基罗达明和 NOS双重阳性神经元分别占四甲基罗达明逆标和 NOS阳性神经元总数的 8.3% ( 14 /16 8)和 18.4% ( 14 /76 )。在此 5 -HT样阳性纤维和终末包绕着 NOS阳性神经元、四甲基罗达明逆标神经元及四甲基罗达明和一氧化氮合酶双重阳性神经元的胞体和树突 ,形成点状紧密接触。本研究结果提示 ,孤束核内来自下行性抑制系统的 5 -HT能纤维和终末可能与向臂旁核投射的 NOS阳性神经元形成突触联系 ,从而可对 NOS阳性神经元所传递的包括伤害性信息在内的内脏感觉传入信息发挥抑制性调控作用     

Ventral specification and perturbed boundary formation in the mouse midbrain in the absence of Hedgehog signaling.

Although Hedgehog (HH) signaling plays a critical role in patterning the ventral midbrain, its role in early midbrain specification is not known. We examined the midbrains of sonic hedgehog (Shh) and smoothened (Smo) mutant mice where HH signaling is respectively attenuated and eliminated. We show that some ventral (Evx1+) cell fates are specified in the Shh-/- mouse in a Ptc1- and Gli1-independent manner. HH-independent ventral midbrain induction was further confirmed by the presence of a Pax7-negative ventral midbrain territory in both Shh-/- and Smo-/- mice at and before embryonic day (E) 8.5. Midbrain signaling centers are severely disrupted in the Shh-/- mutant. Interestingly, dorsal markers are up-regulated (Wnt1, Gdf7, Pax7), down-regulated (Lfng), or otherwise altered (Zic1) in the Shh-/- midbrain. Together with the increased cell death seen specifically in Shh-/- dorsal midbrains (E8.5-E9), our results suggest specific regulation of dorsal patterning by SHH, rather than a simple deregulation due to its absence.     

Contrasting effects of hydroxyurea on cell growth and reduction in Epstein-Barr virus genomes in EBV-infected epithelioid cell lines vs Burkitt's lymphoma cell lines

Eliminating Epstein-Barr virus (EBV) genomes from infected cells is an intriguing theoretical strategy in therapy for EBV-associated malignant diseases. Respective patterns were characterized for hydroxyurea (HU)-promoted loss of EBV genomes from EBV-infected epithelioid cell lines derived from the noncancerous portion of gastric carcinoma tissues and Burkitt's lymphoma (BL) cell lines. Epithelioid cell lines GT38 and PN were less sensitivity to HU than BL cell lines Akata, Raji, and Daudi in terms of cell growth inhibition and cell cycle arrest. On passage in medium with 50 microM HU, the fraction of EBV nuclear antigen (EBNA)-positive cells was reduced substantially in the BL cell lines, but only slightly in the epithelioid cell lines. EBV DNA was reduced in Akata, Raji, and Daudi cells upon passage in 50 microM HU by 95%, 70%, and 50%, respectively, but by only 10% in GT38 cells, in which EBV DNA reduction was enhanced at increased concentrations of HU. This indicates that EBV genome is more easily lost from BL cell lines than from epithelioid cell lines upon culturing in HU. These findings support the view that the elimination of EBV could be therapeutically effective in EBV-associated BL by HU.     

施万细胞对大鼠脊髓半横切后背核神经元存活及其表达NOS的影响

目的：探讨移植的施万细胞对大鼠脊髓半横切后背核神经元存活及其表达NOS的影响。方法：50只成年SD大鼠被分为实验组和对照组。在胸11脊髓段半横切后立即在损伤处移植入施万细胞。结果：脊髓半横切后，15d和25d对照组L1脊髓段损伤侧背核神经元的存活数均比未损伤侧的明显减少。存活的神经元胞体出现明显皱缩，有些神经元呈现NADPH－d阳性。15d和25d施万细胞组L1脊髓段损伤侧背核神经元的存活数则比同期对照组的明显增加，表达NOS的存活神经元数也随之增多。但存活的神经元胞体仍然是皱缩的。结论：移植的SCs可促进受损伤的背核神经元存活及其表达NOS，但不能阻止其胞体出现皱缩。     

Comparison of the efficacy of cell preparations from embryonic ventral mesencephalon of various prenatal age transplanted intrastriatally to rats with 6-OHDA-induced Parkinsonism

Cell preparations of ventral mesencephalon obtained from 8-, 14-, and 16-17-day rat embryos were stereotactically transplanted to homologous rats with 6-hydroxydopamine-induced hemiparkinsonism. Automated analysis of apomorphine-induced motor asymmetry for 3 months after neurotransplantation revealed higher efficacy of cell preparations from 8- and lower from 16-17-day-old embryos. These data correlated with histomorphological findigs, in particular, with the size of grafts, glial reaction, and the number of dopaminergic neurons in the grafts.     

Short term status epilepticus in rats causes specific behavioral impairments related to substantia nigra necrosis

Summary Status epilepticus (SE) was induced for 40 min by flurothyl in well oxygenated rats. This insult resulted in selective destruction of up to 65% of the substantia nigra pars reticulata. We investigated the short and long term behavioral effects of this damage. No deficits were observed in sensorimotor reactivity, locomotor coordination, spontaneous or apomorphine-stimulated locomotor activity in the rats with induced epilepsy. However, these rats exhibited a long-lasting enhancement of amphetamine-stimulated locomotor activity. We propose that this selective impairment is caused by the necrosis of the pars reticulata. This damage might lead to deficient regulation either of mesostriatal dopamine neurons innervating nc. accumbens, or of neurons in the mesencephalic reticular formation mediating the locomotor response initiated in the nc. accumbens.     

Outcome of renal transplantation following a positive cross-match with historical sera: the ASHI survey

Analysis of retrospective data, obtained on 216 patients from 27 centers transplanted across some form of positive lymphocyte cross-match in a noncurrent serum, revealed that actuarial 1-yr graft survival was 69% in first transplants and 53% in recipients of second or subsequent transplants. Graft outcome did not correlate with peak antibody levels, change in antibody from peak to current, remoteness in time of the most recent positive serum, the number or timing of sera cross-matched, the technique or target cell cross-matched, or the degree of positivity of the most recent positive serum. Although a concurrent control population was not available, these results support the concept that acceptable graft survival can be achieved despite a positive cross-match with noncurrent sera.