PICs in motoneurons do not scale with the size of the animal: a possible mechanism for faster speed of muscle contraction in smaller species.

The majority of studies on the electrical properties of neurons are carried out in rodents, and in particular in mice. However, the minute size of this animal compared with humans potentially limits the relevance of the resulting insights. To be able to extrapolate results obtained in a small animal such as a rodent, one needs to have proper knowledge of the rules governing how electrical properties of neurons scale with the size of the animal.

Development of mass spectrometry selected reaction monitoring method for quantitation and pharmacokinetic study of stepharine in rabbit plasma.

Highly sensitive liquid chromatography mass spectrometry method on triple quadrupole (QQQ) mass spectrometer was successfully applied for pharmacokinetic study of stepharine in rabbit plasma. Specific ion transitions of stepharine protonated precursor ion were selected and recorded in the certain retention time employing dynamic selected reaction monitoring mode. The developed method facilitated quantitative measurements of stepharine in plasma samples in linear range of five orders of magnitude with high accuracy and low standard deviation coefficient and pharmacokinetics parameters were calculated.

[Clinical efficacy of reamberin in drug-addicts with hepatic lesions].

Infusion of 1.5% reamberin solution was shown to be a safe tool for combined therapy of severe viral hepatitis in drug addicts with signs of polyorganic lesions. Reamberin had detoxicating, antioxidative, hepato- and nephroprotective effects associated with clinical improvement, reduced hospital stay and normalized biochemical characteristics.

Characteristics and organization of discharge properties in rat hindlimb motoneurons.

The discharge properties of hindlimb motoneurons in ketamine-xylazine anesthetized rats were measured to assess contributions of persistent intrinsic currents to these characteristics and to determine their distribution in motoneuron pools. Most motoneurons (30/37) responded to ramp current injections with adapting patterns of discharge and the frequency-current (f-I) relations of nearly all motoneurons included a steep subprimary range of discharge. Despite the prevalence of adapting f-I relations, responses included indications that persistent inward currents (PICs) were activated, including increased membrane noise and prepotentials before discharge, as well as counterclockwise hysteresis and secondary ranges in f-I relations.

Persistent currents and discharge patterns in rat hindlimb motoneurons.

We report here the first direct measurements of persistent inward currents (PICs) in rat hindlimb motoneurons, obtained from ketamine-xylazine anesthetized rats during slow voltage ramps performed by single-electrode somatic voltage clamp. Most motoneurons expressed PICs and current-voltage (I-V) relations often contained a negative-slope region (NSR; 13/19 cells). PICs activated at -52.

[Efficacy of cytoflavin in therapy of encephalophathy in patients with neuroinfection].

The use of cytoflavin solution in complex therapy of patients with neuroinfection was studied. It showed a favourable effect on the disease clinical process, evident from less pronounced intoxication and meningeal signs by the 11th day of the treatment and improvement of the liquorological picture. The cytoflavin efficacy was also confirmed by normalization of the brain bioelectric activity evident from the electroencephalograms and by reduction of the level of antioxidants, such as metalloproteids and superoxidodismutase, that was in favour of the drug antiinflammatory and antioxidant effects.

[Clinical efficacy of reamberine in therapy for influenza].

Aim: To evaluate the tolerance and therapeutic effectiveness of 1.5% reamberine (RB) solution infusions in complex therapy for pneumonia-complicated pneumonia and acute respiratory diseases (ARD).

Subjects And Methods: 133 patients aged 18 to 60 years with pneumonia-complicated influenza and ARD were examined.

Location and magnitude of conductance changes produced by Renshaw recurrent inhibition in spinal motoneurons.

The mean location of Renshaw synapses on spinal motoneurons and their synaptic conductance were estimated from changes in impedance magnitude produced by sustained recurrent inhibition. Motoneuron impedance was determined by injecting quasi-white noise current into lumbosacral motoneurons of pentobarbital-anesthetized cats. Synaptic location and conductance were estimated by comparing observed impedance changes to simulation results obtained using standard motoneuron models and compartmental models fit to each impedance function.

[Changes in productivity of plant cells as result of cultivation under the space flight conditions].

Effects of space flight on growth and biosynthetic features of plant cells were studied in two strains of ginseng (Panax ginseng) differing in growth and particularly biosynthetic activities, a strain of Lithospermum Erythrorhizon and a strain of Macrotomia Euchroma which produce biologically active naphroquin-derived pigments. --and also differ in growth and biosynthetic properties. Following exposure aboard MIR and a Space shuttle, cells of the callosal cultures were subjected to callosal or suspension passaging.

Correlations between neurograms and locomotor drive potentials in motoneurons during fictive locomotion: implications for the organization of locomotor commands.

The patterns of correlation found between motoneuron pools during fictive locomotion are the same whether the coherence functions used to detect the correlations are determined using pairs of rectified ENGs or motoneuron LDPs and rectified ENGs. This finding suggests that the higher frequencies in rectified ENGs (and, perhaps, EMGs) contain information about the synaptic input to motoneurons. Nevertheless, differences between the coherence functions of rectified ENG pairs and those of LDPs and rectified ENGs suggests that this information is distorted by harmonics introduced by rectification.

Organization of recurrent inhibition and facilitation in motoneuron pools innervating dorsiflexors of the cat hindlimb.

The incidence of recurrent inhibition and facilitation in motor nuclei innervating the dorsiflexors of the ankle and digits was examined in spinalized, decerebrate cats. Motoneurons innervating the anterior and posterior portions of the tibialis anterior (TAa and TAp, respectively) received strong recurrent inhibition following stimulation of either of the homonymous muscle nerves. Both motoneuron species received substantial recurrent inhibition from the semitendinosus (St), but stimulation of the nerve to the extensor digitorum longus (EDL), an ankle flexor synergist, evoked smaller recurrent IPSPs.

Organization of recurrent inhibition and facilitation in motor nuclei innervating ankle muscles of the cat.

The distribution of recurrent inhibition and facilitation to motor nuclei of muscles that act at the cat ankle joint was compared with the locomotor activity and mechanical action of those muscles described in published studies. Emphasis was placed on motor nuclei whose muscles have a principal action about the abduction-adduction axis and the pretibial flexors: tibialis posterior (TP), peroneus longus (PerL), peroneus brevis (PerB), the anterior part of tibialis anterior (TA) and extensor digitorum longus (EDL). Most intracellular recordings in spinalized, unanesthetized decerebrate cats showed only inhibitory or excitatory responses to antidromic stimulation of peripheral nerves, but mixed effects were also seen.

[Isolation and properties of superoxide dismutase from human blood plasma].

A procedure for purification of superoxide dismutase (SOD) from human blood plasma has been developed, which includes gel filtration on Ultrogels AcA-34 and AcA-44 (LKB, Sweden). The protein purified from blood plasma is a glycoprotein which is thermostable at 70-80 degrees C. The molecular mass of the protein determined immediately after gel filtration is approximately 147,000 daltons.

[The immunoenzyme analysis of ceruloplasmin].

A highly specific and sensitive enzyme immunoassay (EIA) system, suitable for the qualitative analysis of ceruloplasmin, has been developed. The possibility of its use for the examination of children with mononucleosis and pseudotuberculosis has been studied. An increase in the concentration of ceruloplasmin has been more pronounced in infectious mononucleosis (0.

[Electrostimulation of the uterus in uterine inertia].

The paper provides the results of electrostimulation application to the therapy for uterine inertia. Monopolarization current action on the cervix was shown to be beneficial in 83.34% females with abnormal labor.

[Reversibility of the effect of the change in time of the magnetic field on molluscan neurons].

Influence of a single impulse of magnetic field (MF) of trapezoidal shape with 10 Oe amplitude on neuron electrical activity (EA) of Lymnaea stagnalis was studied. It has been found that both leading and trailing edges of MF impulse separately were able to change EA of the cells. Nevertheless the impulses with a short time between the edges were found to be of small efficiency.

[Responses of neurons of the parietal association cortex of the cat to acoustic stimulation before and after suppression of the auditory cortex in the cat].

The aim of this work was to study the influence of auditory cortex suppression in cat on response patterns of the parietal associative cortex neurons responding to different frequency tones. Suppression was performed by two methods: bilateral isolation and application of 6% nembutal solution on the cortex surface. Frequency-thresholds curves were plotted for all neurons studied.

[Effect of a series of small amplitude magnetic field pulses on the electrical activity of mollusk neurons].

Possibility of summing up in time the effects of small values of impulses of 1 Oe magnitude magnetic field (MF) on the electrical activity (EA) of Lymnaea stagnalis neurons was studied. The single impulse of MF did not cause changes in neurons EA. EA changes took place under the action of 5-8 impulses of MF.

[Effect of a single magnetic field pulse on the electric activity of mollusk neurons].

The influence of a single impulse of magnetic field (MF) of triangular shape of neuron electrical activity (EA) of Limnaea stagnalis registered intracellulary was studied. The dependence of the neuron reaction on the MP speed changing has been found. The effective values of speeds of impulse fronts were within 0,1 to 10,0 mT/c range.