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A Ia Ivanov

Publications and source records attributed to A Ia Ivanov.

At least 19 recordsLinked to original sources
PubMed1989

[The nature of the background activity in identified neurons of the rat superior cervical ganglion before and after partial denervation of the submandibular gland].

The ongoing activity of the ganglionic cells innervating the normal and partial denervated submandibular gland of rat was investigated with intracellular recording. With the aim to be identified these cells were preliminary labeled by the fluorescent dye Di-1. The most of neurons innervating the normal gland were entirely silent. Ongoing activity was found only in 11% of these neurons and the average frequency of discharge was 0.1 +/- 0.01/s. After partial denervation of the gland, the number of active ganglion cells among the neurons innervating the gland increased from 11 to 42%. The average frequency of discharge in these cells has increased about three times. The data suggest that changes found in neurons innervating the partially denervated gland were a result of the increase in convergence of preganglionic fibres on these neurons.

Animals↗
PubMed1987

[Characteristics of the tonic activity in different groups of neurons of the superior cervical ganglion in the rabbit].

The patterns of tonic activity were studied by intracellular recording from neurons of rabbit superior cervical ganglion at rest and with stimulation of chemoreceptors. According to reflex changes in the activity pattern all neurons studied were classified into three groups by the functional value. Action potentials of the first and second types may be observed in the tonic activity of all groups, that suggests the presence of dominant and accessory inputs for neurons innervating various target organs. The analysis of changes in action potentials and EPSP frequencies of tonic activity for neurons of different groups makes it possible to suggest that preganglionic fibres converging on the neurons of these groups possess a similar type of tonic activity.

Animals↗
PubMed1984

[Conduction pathways of the lumbar ganglia of the paravertebral sympathetic trunk in the rabbit].

The conducting pathways of the lumbar (L3-L5) sympathetic ganglia were studied in rabbits by recording action potentials evoked in the nerves of the ganglia by stimuli applied to their other nerves and intracellular recording. It is established that some presynaptic fibres enter the sympathetic chain via grey rami and then pass upward and downward making synaptic contacts with ganglionic neurons. Other fibres enter the sympathetic chain through white communicating rami and pass in descending direction giving collaterals to the neurons of the ganglia. Descending preganglionic fibres with different conduction velocity converge on ganglionic neurons.

Action Potentials↗
PubMed1983

[Transmission of excitation through the superior cervical ganglion at an early stage of postnatal development].

The action of hexonium, d-tubocurarine, phentolamine and atropine on synaptic transmission in the superior cervical ganglia of rabbit, cat and rat was studied at early postnatal stages (1-8 days after birth). It was shown that hexonium and d-tubocurarine (intravenous injection or addition to Kreb's solution) inhibit the transmission of excitation in the ganglia both in situ and in vitro. No difference was found in the action of phentolamine and atropine on synaptic transmission in the ganglia of newborn and adult animals. A conclusion is made that synaptic transmission in sympathetic ganglia at early postnatal stage is cholinergic.

Acetylcholine↗
PubMed1983

[Analysis of tonic activity in sympathetic ganglion neurons in the rabbit].

The patterns of tonic activity recorded with intracellular electrodes from neurons of the rabbit superior cervical ganglion whose preganglionic inputs remained intact were compared with the responses of the same neurons to single stimuli applied to preganglionic fibres. It is found that each neuron receives two preganglionic inputs, dominant and accessory. The dominant input is formed by one preganglionic fibre with a potent synaptic action on the neuron evoking a spike with high safety factor. The accessory input is formed by two or more converging preganglionic fibres that can evoke a spike only due to summation of evoked EPSPs.

Action Potentials↗
PubMed1981

[Properties of the slow excitatory postsynaptic potential in mammalian sympathetic ganglia neurons].

Slow EPSPs evoked in the neurons of the rabbit isolated superior cervical ganglion were studied using intracellular microelectrodes. Two types of EPSPs occurring in different neurons were found. The type I slow EPSPs showed an increase during hyperpolarization of the membrane and a decrease during its depolarization. Input resistance of the neurons during the response either decreased or remained unchanged. The type II slow EPSPs were increased by depolarization and decreased by hyperpolarization with the reversal potential -78.9 +/- 3.6 mV. Depolarization evoked by acetylcholine or carbocholine was followed by an increase in the input resistance in 53% of neurons with reversal potential -83.2 +/- 6.7 mV. It is concluded that in the first group of the neurons the nature of the slow EPSP is similar to that of ordinary EPSP. The main component underlying the ionic mechanism of slow EPSP in the other group of the neurons is a decrease in potassium conductance of the membrane.

Acetylcholine↗
PubMed1977

[Goodpasture's syndrome].

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Anti-Glomerular Basement Membrane Disease↗
PubMed1975

[Peridural anesthesia with neuroleptoanalgesia in operations for goiter].

The paper is concerned with the use of peridural anesthesia (PA) in operations for struma in a considerable size and retrosternal localization of the latter, thyrotoxicosis, grave concomitant lesions. The authors have employed PA in 12 patients, in 2 of them in association with endotracheal narcosis, in 9 in combination with neuroleptoanalgesia (NLA), and in 1 postoperatively to liquidate successfully the laryngeal mucosa edema, developed following surgery for struma performed under endotracheal narcosis.

Acid-Base Equilibrium↗
PubMed1975

[The spontaneous electrical activity of the isolated rabbit superior cervical ganglion].

Spontaneous electric activity (mean amplitude of impulses--200-300 muV and frequency--0.0m-2.9 Hz/s) was observed in isolated rabbit superior cervical symphathetic ganglia using the sucrose-gap method. This spontaneous activity was completely abolished by d-tubocurarine (5-10(-5) M) and hexamethonium (1-10(-4) M). The frequency of the spontaneous discharges was increased by doubling of osmotic pressure, increasing of [K]0 and adding theophilline or ethanol to perfusing solution. These findings suggest that the activity observed is due to spontaneous release of the transmitter by preganglionic nerve endings. However tetrodotoxin in relatively low concentrations (2.5-5-10(-7) g/ml) reversibly inhibited this activity. In high [Ca]0 solutions spontaneous discharges of an isolated ganglion were reduced or completely blocked. These facts suggest that the action potential generation mechanisms also participate in the spontaneous activity of the isolated cervical sympathetic ganglion.

Action Potentials↗
PubMed1975

[Surgical treatment of injuries of large blood vessels of the limbs].

In treatment of 50 patients with injuries of large vessels of limbs the authors have employed all kinds of vascular plasty, including lateral and circular sutures, putting of a patch on the vascular wall, replacement of an arterial defect with an autovenous graft. Autovenous plasty employed in various modifications in 21 cases is felt to be the method of choice in operations on injured arteries in cases of an extensive damage of soft tissues of limbs and open fractures. The results of the treatment are described.

Arm↗