Treatment of intestinal dysbacteriosis in children with diabetes mellitus]

The use of the probiotic Acylact in combination with Viferone containing human recombinant interferon-alpha 2 in the treatment of intestinal dysbacteriosis in children with insulin-dependent diabetes mellitus (IDDM) was shown to be highly efficient. Elimination of microecologic disorders in the intestine was accompanied in all the children by immune rearrangements. The quantity of secretory and serum immunoglobulins and complement increased and the white blood cell chemiluminescence proved to be higher. The correction of the immune status of the children with IDDM resulted in a certain decrease of glycemia. The data are indicative of the fact that such a treatment of intestinal dysbacteriosis in children with IDDM is promising.     

Microsporidiosis of Sakhalin Salmonidae: the incidence and dynamics of the infection

Four-year summer observations have shown that G. takedai distribution in Salmonidae of Sakhalin is limited by the rivers entering the Aniva Bay. Maximum infection of pink salmon (Oncorhynchus gorbuscha) amounts to 70-100%, that of masu salmon (Oncorhynchus masou) to 9.0-45.6% and was recorded in September. Dynamics and possible ways of infection are discussed.     

Convergence of signals of various sensory modalities on the neurons of the sensorimotor zone of the rabbit cerebral cortex

The responses of the neurons to electrocutaneous stimulation, light flashes, and clicks in the cortical region of the motor representation of the rabbit forelimb were investigated by means of intra- and quasiintracellular recordings. In unanesthetized animals, in only eight out of 65 neurons did postsynaptic potentials (PSP) with a short (10–30 msec) latent period arise in response to light and sound. In 15 neurons, long latency (50–150 msec) responses to one or both of these stimuli were recorded. In most of the cells, short latency stable responses to stimulation of the contralateral forelimb and unstable long latency responses to light and/or sound, frequently of the nature of an increase in the background "synaptic noise," were observed. Under deep chloralose narcosis, the type of convergence was sharply changed: in most of the neurons, short latency responses to all the stimuli used appeared. However, the picture of convergence differed from that described earlier [5,6] for the motor cortex of the cat under chloralose narcosis. The responses to various stimuli were less similar to one another; the somesthetic modality substantially "predominated" (judging by the stability and nature of the interaction of the response).Brain Institute, Academy of Medical Sciences of the USSR. Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 3, No. 5, pp. 474–483, September–October, 1971.     

Quantal analysis of long-term posttetanic changes in minimal postsynaptic potentials of hippocampal slices in vitro

Minimal excitatory postsynaptic potentials (EPSP) were investigated in 13 neurons under single or double-pulse near-threshold microstimulation of the radial layer (Schaffer's collaterals) and stratum oriens in surviving hippocampal slices (area CA1) in guinea pigs. The amplitude of 23 EPSP (9 units; 12 pathways) rose after tetanization of Schaffer's collaterals over a 5–55 min period, taken as long-term potentiation (LTP). Statistical analysis conducted using four methods of quantal hypothesis based on a binomial approximation revealed an increase in mean quantal content (m) during LTP. The rise in quantal size was only statistically significant when using data obtained from a section of these methods (mainly for stretches of over 15 min following tetanization) and shows no correlation with intensity of LTP. The pronounced rise in m demonstrated using different methods matches data from experiments on intact animals and indicates a presynaptic location of the mechanisms underlying protracted persistence of residual tetanization lasting some tens of minutes.Institute for Brain Research, All-Union Mental Health Research Center, Academy of Medical Sciences of the USSR, Moscow. Max-Planck Institute of Biophysical Chemistry, Göttingen, Germany. Zoological Institute, Jagiellonian University, Cracow, Poland. Translated from Neirofiziologiya, Vol. 22, No. 6, pp. 752–761, November–December, 1990.     

Effects of "non-quantal" acetylcholine on miniature endplate currents in mice

The possibility of postsynaptic potentiation (PSP) and desensitization developing due to nonquantal acetylcholine (ACh) secretion was investigated in mouse diaphragm with reference to time-amplitude relationships of miniature endplate currents (MEPC). The H effect (which characterizes nonquantal secretion (NS) of ACh) fell to zero over 3 h under the action of armine-induced inhibition of acetylcholinesterase (AChE) at a temperature of 20°C. A decline in the decay time constant () of MEPC unaccompanied by observable alteration in MEPC amplitude occurred at the same time. This accelerated decay of MEPC was not observed in the absence of NS (the early stages of denervation). Start of NS did not show any effect on maximum retardation of MEPC decay due to AChE inhibition, indicating that no PSP sets in under the effects of non-quantal secretion. The effect of decline in accelerated with a rise in temperature; it could be reproduced with neostigmine replacing armine, while remained unchanged in the time spells investigated with AChE in its active state. Non-quantal ACh is not thought to produce substantial retardation of MEPC decay, although it does bring about desensitization, signs of which may be partially masked owing to concurrent onset of PSP.S. V. Kurashov Medical Institute, Kazan'. Translated from Neirofiziologiya, Vol. 22, No. 4, pp. 507–513, July–August, 1990.     

Estimate of the quantum value variability in excitatory synapses of CA1 area in hippocampal slices and its effects on the quantum value estimate

Excitatory postsynaptic potentials (EPSPs) evoked by near-threshold stimulation of the radial layer were recorded from the CA1 area of guinea pig hippocampal slices. An optimization method based on the deconvolution technique was used to reconstruct a noise-free discrete distribution of the amplitudes with regular (quantal) intervals (v) between the discrete components. The standard deviation of v (Sv) was studied for its effect on the estimate of the v value. Twenty-two amplitude distributions with approximately regular, visually distinguishable peaks were analyzed. It was found that, in some cases, too small (<0.1–0.15 v) or too large (>0.3–0.4 v) Sv led to lower v estimates in comparison with those obtained for Sv in the range of 0.1–0.3 v. Computer experiments have shown that too small or too large Sv values may lead to underestimates of the stimulated v values. The average underestimate for physiological data is probably 10–15%, but, in some cases, it may be higher. Judging from a maximal verisimilitude criterion, optimal v estimates are obtained for Sv between 0 and 0.15 v. Comparison of simulated and physiological data suggests that the variation coefficient of v for hippocampal synapses formed by radial fibers on CA1 neurons is equal to 0.1–0.2 Sv values generally accepted for the deconvolution procedure (0 or 0.05 v) seem to be underestimated for central synapses, while Sv>0.3 v are overestimated. Underestimates of Sv known from literature may be due to a dependence of the deconvolution procedure results on the noise level, as well as due to a probable nonlinear interaction between the signal and noise. Overestimates may be a result of multiple spontaneous quantal release.Translated from Neirofiziologiya, Vol. 25, No. 1, pp. 10–17, January–February, 1993.     

Synaptic reactions of sensomotor cortex neurons to stimulation of emotionally significant brain structures

The study deals with synaptic and spike responses of neurones in the rat sensorimotor cortex to stimulation of the lateral and medial hypothalamus, locus coeruleus and raphe nuclei. The activity of 57 neurones was recorded, 41 of them intracellularly and quasi-intracellularly, in response to the stimulation of sites in these structures, which were previously identified as "emotionally/ significant. No considerable differences in the effects of the stimulation of different "emotiogenic" zones were found. The stimulation parameters, differing from the "behavioural" ones by a greater strength, elicited in the majority of neurones clear post-synaptic responses, often in the form of EPSP-IPSP. Latencies of the responses varied from 3 to 80 msec. The most stable and pronounced responses were obtained to the stimulation of the lateral hypothalamus. No significant correlations of the latencies of the responses to the stimulation of different "emotiogenic" structures were found.     

Calculation of theoretical postsynaptic potential amplitude distribution in quantum analysis

It is suggested that in equations usually used to calculate curves of theoretical distributions of PSP amplitudes in the course of quantum analysis the effect of variations in the quantum values themselves is overestimated and variations in noise level are not taken into account. An equation allowing for both these parameters is suggested. Statistical analysis of "elementary" PSPs of the parietal ganglion ofHelix pomatia and of "minimal" PSPs of hippocampal neurons showed the necessity of allowing for noise variations. By means of the suggested equation theoretical distributions agreeing better with the experimental according to thex ² criterion can be found and variation in the quantum itself can also be determined indirectly.Brain Institute, Academy of Medical Sciences of the USSR, Moscow. Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 11, No. 2, pp. 146–50, March–April, 1979.