Self-sustained rhythmic spike and wave activity and response of glial and nerve cells in the cat sensorimotor cortex

During acute experiments on unanesthetized cats, immobilized with myorelaxants, it was found that during rhythmic stimulation (8–14 Hz, duration: 10 sec) of the ventroposterolateral thalamic nucleus brief hyperpolarization is succeeded by depolarization in the pyramidal neurons of the sensorimotor cortex. Following this depolarization, rhythmic (approximately 3 Hz) paroxysmal depolarizing shifts in membrane potential are produced by ending stimulation, succeeded by protracted hyperpolarization and termination of rhythmic wave activity. Depolarization only is observed in glial cells, however, while hyperpolarization sets in after hyperpolarization is completed in the neurons. It is suggested that long-term changes in the membrane potential of cortical cells could make some contribution to the setting up and termination of rhythmic spike and wave activity.I. S. Beritashvili Institute of Physiology, Academy of Sciences of the Georgian SSR, Tbilisi. Translated from Neirofiziologiya, Vol. 18, No. 3, pp. 319–325, May–June, 1986.     

真盐生植物盐地碱蓬根系边缘细胞在耐盐中的作用初探

以黄河三角洲潮间带盐地碱蓬种子生成的幼苗为材料,研究了NaCl胁迫对盐地碱蓬生长与根系边缘细胞的影响。盐地碱蓬的第一个边缘细胞几乎与根尖同步产生,当根长达到13mm时,边缘细胞数目达到最大值。NaCl胁迫抑制边缘细胞的活性,但低浓度的NaCl处理增加边缘细胞的数目。低浓度NaCl处理时果胶甲基酯酶（PME）的活性比对照有明显增加,超氧化物歧化酶（SOD）活性随着NaCl浓度的增加呈现先上升后下降的趋势,低浓度NaCl可以增加盐地碱蓬根内过氧化氢酶（CAT）的活性,NaCl处理时间和处理浓度都对过氧化物酶（POD）活性的影响不明显。这些结果表明,盐地碱蓬至少部分通过增加调控活性氧（ROS）水平增加PME活性及根系边缘细胞数目来抵抗NaCl胁迫。     

A Study of the Structure of Trypsin-Like Serine Proteinases. 2. A Study of Tryptophan Fluorescence in Variants of Miniplasminogen with an Altered Primary Structure

Biophysics - Abstract—Variants of miniplasminogen with an altered primary structure have been designed to study previously described changes in tryptophan fluorescence during plasminogen...     

Background impulse activity of neurons of the fastigial nucleus in the rat cerebellum

Background impulse activity (BIA) of neuronal elements of the fastigial nucleus (FN) of rat cerebellum were investigated for the first time with the aid of various methods of statistical analysis. A clear predominance of stationary impulse flows (IFs) was discovered, along with irregularities in such flows, variously expressed and including a significant number of realizations of a regular component of impulse activity. Nonstationary IFs constituted a special variety of BIA; they were found in 15% of the total number of neurons investigated. Serial correlation analysis of the durations of interspike intervals (ISIs), both of stationary and nonstationary IFs, allowed us to identify six main varieties of ISI dynamics in the BIA of neurons of the fastigial nucleus. The patterns of recorded IFs and variations in IFs can serve as an adequate indices of the state of cellular activity during intracellular recording from cells of the central nervous system.L. A. Orbeli Institute of Physiology, Armenian Academy of Sciences, Yerevan. Translated from Neirofiziologiya, Vol. 23, No. 4, pp. 441–450, July–August, 1991.     

Antimicrobial Activity of Lactic Acid Bacteria from Sour Milk Products Narine, Karine, and Matsun

We studied antimicrobial properties of lactic acid bacteria from sour milk products Narine, Karine, and Matsun. The whey of the sour milk products included two major fractions, of sugars and L-lactic acid and its sodium and calcium salts. Antimicrobial activity of Narine, Karine, and Matsun was related to the presence of L-lactic acid and its sodium and calcium salts.     

胶质瘢痕对神经系统损伤的保护作用

胶质瘢痕是神经系统损伤后由反应性星形胶质细胞,小胶质细胞及其分泌的细胞外基质组成。早期的研究多集中于胶质瘢痕在抑制轴突生长,神经细胞再生等方面的作用。而最新的研究表明胶质瘢痕的形成对损伤急性期神经细胞具有重要的保护作用。本文从瘢痕组织在损伤缝合和组织重构、局部免疫调节、神经再生等方面对神经损伤的保护作用进行综述。     

Hexameric purine nucleoside phosphorylase II from Escherichia coli K-12. Physico-chemical and catalytic properties and stabilization with substrates

Some properties of hexameric purine nucleoside phosphorylase II (EC 2.4.2.1) from Escherichia coli K-12 were studied. The enzyme obeys the Michaelis-Menten kinetics with respect to purine substrates (Km for inosine, deoxyinosine and hypoxanthine are equal to 492, 106 and 26.6 microM, respectively) and exhibits negative kinetic cooperativity towards phosphate and ribose-1-phosphate. The Hill coefficient is equal to approximately 0.5 for both substrates. Hexameric purine nucleoside phosphorylase II is not a metal-dependent enzyme; its activity is inhibited by Cu2+, Zn2+, Ni2+ and SO4(2-). The enzyme is the most stable at pH 6.0; it contains essential thiol groups. All substrates partly protect the enzyme against inactivation by 5.5'-dithiobis(2-nitrobenzoic acid) and heat-inactivation and, with the exception of phosphate-against inactivation by p-chloromercuribenzoate. Hypoxanthine, especially in combination with phosphate, afford the best protection against inactivation.     

Electrical activity of mauthner neurons of goldfish Fries <Emphasis Type="Italic">in vitro</Emphasis>

We studied the electrophysiological characteristics of Mauthner neurons (MN) in in vitro preparations of the medulla fragments of goldfish fries. The characteristics of extracellularly recorded responses of MN were found to be close to those usually recorded in vivo. It was demonstrated that in vitro intracellular microelectrode recording of MN activity in goldfish fries is, in principle, possible. The main experimental approaches for successful intracellular recording from such objects have been developed, and the possible artifacts met in the course of the experiments, as well as the parameters of stimulation, have been identified.Neirofiziologiya/Neurophysiology, Vol. 36, No. 4, pp. 288–296, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.