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Biomedical subjects

V V Shul'govskiĭ

Publications and source records attributed to V V Shul'govskiĭ.

At least 19 recordsLinked to original sources
PubMed1994

[Enkephalinase mechanisms of tolerance of analgetic action of opioids. Effects of D-phenylalanine and naloxone].

The paper reviews the data available in the literature and the authors own data demonstrating the differences in the levels of endogenous opioids and in the effects of enkephalinase inhibitor and naloxone in morphine-responsive and morphine-resistant and -tolerant animals. In the morphine-tolerant animals, a single administration of enkephalinase inhibitor or some doses of naloxone was found to produce an analgesic effect leading to a short-term analgesic effect of morphine. Chronic administration of naloxone causing a gradual decrease in and subsequent cessation of its analgesic effect leads to recovery of morphine's analgesic effect in the drug-resistant and -tolerant animals. It is suggested that the morphine-resistant animals have a congenital high activity of enkephalinase, while the drug-tolerant ones have its acquired high activity. Naloxone in certain doses with the high activity of enkephalinase act as its inhibitor, but in high doses acts as its opioid antagonist.

Animals↗
PubMed1992

[The effect of amiridin on the MPTP-induced Parkinson-like syndrome in monkeys].

Development of behavioral disturbances was investigated during N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration (0,2 mg/kg, i/m, at 48 h. intervals, total dose 11.2-13.2 mg/kg) in experiments on two monkeys Macaca rhesus. MPTP induced the complex of symptoms, which are typical for idiopathic Parkinson's disease. Administration of amiridine (0,25-0,4 mg/kg) to MPTP-treated monkeys caused gradual decline of Parkinson syndrome. Mechanisms of action of amiridine are discussed.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1989

[The biphasic selective effect of an antiserum to beta-endorphin on pain sensitivity in rats].

In rats beta-endorphin antiserum systemic injection decreased during 1-2 days the threshold of tail-shock and latency of tail-flick tests, and during subsequent 85 days increased the threshold of tail shock, but not changed the latency of tail-flick tests. Naloxone injection blocked the increasing of thresholds, but not changed the latency of tail tests. It is suggested that antiserum evokes the first inhibition and the second selective activation of endogenous antinociceptive opioid system with affinity to electric nociception.

Animals↗
PubMed1988

[The hypothesis of the "efferent copy" in saccade programming in cats].

Horizontal eye movements in cats were recorded using the magnetic search coil method. Saccadic eye movements were linearly approximated. For combined eye and head movements the slope of lines was independent of maximal head velocity within the studied range (up to 250 degree/s). Saccades slowed down with a restrained head. The duration of the gaze shift grew with an increase of its amplitude. The amplitude of gaze was found to depend on the head velocity. Experimental data on the interaction of eye and head movements during the coordinated goal displacements are interpreted from standpoint of the saccadic signal suppression by the "efferent copy" signal for head movements.

Animals↗
PubMed1983

[Neuronal correlates of the motor function of the cerebral motor cortex].

Modern ideas about the motor cortex neuronal mechanisms ensuring the initiation and correction of the instrumental manipulational movements in mammals have been analysed. A close correlation has been established to exist between the neuronal activity and various characteristics of movement including those that are not induced by muscle force. The role of somatic afferentation in the formation and realization of the movement programme is analysed as well as in motor output modulation by means of fast feedback.

Afferent Pathways↗
PubMed1979

[Statistical analysis of the functional features of cat motor cortex neurons].

Recordings were made from 366 neurons situated in the motor area of m.biceps in the cortex of 6 cats trained to make instrumental placing reaction and to accept manipulation of the joints and natural cutaneous stimulation of the forelimb. From 160 neurons whose discharges changed during placing reaction performance 52 (32.5%) were demonstrated to receive an input from peripheral receptors in the forelimb. In contrast only 7 (3.4%) neurons in the group not related to the movement received such an input. From 160 neurons 31 changed discharge before movement onset, 59 after movement onset, and 70 before and during movement. Correlation between functional types of the neurons and their peripheral inputs was found.

Animals↗
PubMed1977

[Sensory input to neurons of the motor area of the biceps in cat cortex].

Correlation between activity of cortical neurons in the biceps motor area and a conditioning movement of the contralateral forelimb was studied in chronic experiments of two male cats. In the group of neurons related to the movement sensory inputs were not found in 68.1% of neurons, in the group not related to the movement in 97.9% of neurons. 24.2% of neurons from the first group had cutaneous receptive fields on the dorsal surface of the distal part of the moving forelimb, in this group 5 neurons had inputs from the forelimb joints.

Animals↗
PubMed1976

[Properties of rhythmic discharge by cat motor cortex neurons evoked by a continuous current through their membranes].

The properties of rhythmic discharge of motor cortex neurons evoked by dc depolarizing current through the membrane were studied in acute experiments on immobilized cats. Linear relation between the rate of rhythmic discharge and the strength of current was revealed, the slope of this relation being 18-10.7 imp/s nA. Correlation between input resistance and the slope of the discharge frequency current curve was demonstrated. Two types of adaptation to current were observed: exponential and undamped oscillations. The relation of the latency of the first spike and first interspike interval to current was hyperbolic. The role of dendrites in the observed phenomena is discussed.

Action Potentials↗
PubMed1975

[Electrical characteristics of neurons in the motor region of the cat cerebral cortex].

Electrical parameters of motor cortex neurons were studied in acute experiments on cats. Input resistance of cortical neurons varied from few to some tens of Momega (mean value 11.11 +/- 3.93 Momega). A hyperbolic relation between threshold current and input resistance for cortical neurons was found. Velocity of axon conduction and input resistance are negatively correlated. Time constant of the membrane (to) was 7.1 +/- 3.46 ms. In some neutrons a second time constant t1= 1.65 +/- 0.36 ms was also found. Using result of Rall's model, the electronic length of the dendrite was computed, it was found to be 3.66-0.94 in units of length constant. These data are compared with those obtained on motoneurons. Functional significance of electrical parameters of cortical neurons is discussed.

Action Potentials↗
PubMedDate not supplied

[The effect of the visual stimulation of the leading and nonleading eye on the value of the saccadic latency period and on the peak latency of rapid presaccadic potentials].

Visual targets were presented monocularly to the leading and nonleading eyes. The complex of rapid positive and negative potentials was studied using the reverse summation from the onset of saccades. The latencies of saccades and peak latencies of the averaged presaccadic potentials were measured. The dependence of the saccade latencies and peak latencies of the complex of potentials on stimulation of the leading or nonleading eye and saccade direction was not simple and was largely determined by the individual profile of asymmetry. It is suggested that during stimulation of the leading eye the processes of attention fixation and switching as well as of the space visual processing are faster than during stimulation of the nonleading eye. Thus, the leading role of the right eye is reflected not only in fixation processes but also in movement anticipation.

Adult↗