[The action of adrenergic substances on the smooth muscle of the rat trachea]. / Deistvie adrenergicheskikh veshchestv na gladkuiu myshtsu trakhei krysy.

Adrenalin and noradrenaline first induced an increase in the trachea smooth muscle response with its subsequent decline in rats. Phentolamine decreases the muscle responses in its thoracic part and practically does not affect it in the cervical segments. The adrenergic neural fibres seem to terminate at the smooth muscle cells and the neurons of intramural ganglia.

[The neuronal impulse activity of the subepicardial plexus in the isolated heart of the cat]. / Impul'snaia aktivnost' neironov subépikardial'nogo spleteniia v izolirovannom serdtse koshki.

The unit activity recorded in the right atrium plexus of the Langendorff preparation was spontaneously irregular in 20 per cent of the neurons. Hexamethonium abolishes it. The spontaneous activity and vagus-induced discharges were inhibited by adrenaline or by stimulation of the stellate ganglion in nearly 30 per cent of the neurons. Activity of some spontaneously active units depended on the effect of the experimental procedure.

[The age-related characteristics of changes in osmotic and ionic homeostasis in spontaneously hypertensive rats]. / Vozrastnye osobennosti izmenenii osmoticheskogo i ionnogo gomeostaza u spontanno-gipertenzivnykh krys.

The 3-month old SHR differ from the WKY rats in that the former have an increased osmolality, concentration of albumins, activity (but not the concentration) of sodium and a reduced activity of potassium. The shifts in the albumins concentration occur, mainly, on account of the amino acid phenylalanine. The gradient increase of the sodium and potassium concentration between the plasma and muscular tissue in followed by a slight hyperpolarisation of the muscle fibers, a drop in the lability and a increase in pO2. The above shifts of homeostatic parameters were not revealed in the SHR and WKY rats of 1.5 and 6.0 months of age.

[The functional properties of the intramural bladder neural plexus]. / Funktsional'nye svoistva intramural'nogo puzyrnogo nervnogo spleteniia.

In the cat isolated bladder, decentralization of the bladder plexus first decreased spontaneous unit activity. Later, after degeneration of preganglionic nervous fibres, intensified functioning of own reflex arches of the plexus maintained the coordination of activity in different areas of the bladder. Due to an increased excitability and chemosensitivity, the neurons are to a larger extent recruited in the activity of the reflex arches. Some bladder reflexes can be circuited within the bladder plexus.

[Homosynaptic depression--a model of the habituation phenomenon]. / Gomosinapticheskaia depressiia--model' fenomena privykaniia.

A high functional stability of the cat spinal cord motoneurons was shown in conditions of long-term orto- and antidromic activation with frequency corresponding to their natural rhythmicity. The depression of reflex discharges was shown to be related not to any postsynaptic depression or presynaptic inhibition but to a drop of probability of the transmitter release from the primary afferents' terminals. Analysis of signs of the habituation phenomenon revealed their similarity to the homosynaptic depression phenomenon and, consequently, their submittance to the same principles of experimental analysis and consideration.

[Effect of neuropeptides on the motor output of the buccal ganglia of freshwater mollusks]. / Vliianie neiropeptidov na motornyi vykhod bukkal'nykh gangliev presnovodnykh molliuskov.

Hypertensin, gastrin-releasing peptide, neuromedin and substance P activated the buccal ganglia in Planorbis corneus and Lymnaea stagnalis, whereas secretin, somatostatin, pancreosimin and octapeptide of cholecystokinin suppressed them. No effect of neurotensin and alitesine were found. The peptides seem to rearrange functioning of buccal nervous network. Application of the peptides induced no pattern of food program.

[Processes facilitating conduction in the vesical plexus of the cat]. / Protsessy oblegcheniia provedeniia v puzyrnom spletenii koshki.

In the cat isolated bladder plexus, cholinergic transmission from parasympathetic "entry" was shown to be less obvious at low-frequency stimulation and much more effective (up to 300-1800%) at a high-frequency one (1-20/sec). During posttetanic potentiation (up to 5 min) it is possible to reach the 100% saturation of ganglion motor pool. The phenomena of facilitation were shown to be conducted through presynaptic mechanisms. The facilitation processes are more obvious in the bladder plexus than in sympathetic ganglia and allow to filtrate low and amplify high frequencies of activation which is particularly significant during urine storage and evacuation.

[Adrenergic mechanisms of the cystic plexus in the cat]. / Adrenergicheskie mekhanizmy puzyrnogo spleteniia koshki.

Hypogastric and pelvic nerves were stimulated in experiments carried out on isolated vesical plexuses of the cat as well as intra-or extracellular recording of the activity of vesical ganglion neurons was conducted. Characteristics of evoked responses, ganglionic lability, rhythmic and posttetanic potentiation were studied. Homosynaptic presynaptic origin of posttetanic potentiation was noted. Suppression of ganglionic recording in stimulation of sympathetic fibres and in intraarterial injections of catecholamines is suggested to be connected with presynaptic adrenergic inhibition. This suggestion was confirmed in experiments with administration of reserpine and phenoxybenzidine .

[Reactive changes in autonomic synapses during frequency electric stimulation]. / Reaktvinye izmeneniia vegetativnykh sinapsov pri ikh chastotnoi élektrostimuliatsii.

Reactive modifications of synapses of isolated intratrunkal vegetative neurones induced by high frequency orthodromal electric stimulation have been examined by vital phase-contrast microscopy, electron microscopy, vital staining with methylene blue in conjunction with concurrent electrophysiological control Flocculent aggregation of the synaptoplasma and vesicles has been discovered, which is associated with higher adhesiveness of modified proteins. There have been also discovered matrix translucence and rounding of the living synaptic buds, which is accounted for by segregation of the hydration fraction of the neuroplasma. The decrease in the number of light synaptic vesicles is accompanied by the appearance of osmiophilic, myelin-like bodies, dense-core vesicles and glycogen-like granules. An attempt has been made to validate the process in terms of the colloid-chemical conception.

[Electrophysiologic analysis of mediator stores and release in smooth muscle synapses of the nictitating membrane in cats]. / Elektrofiziologicheskii analiz zapasov i vysvobozhdeniia mediatora v sinapsakh gladkoi myshtsy migatel'noi pereponki koshki.

At the adrenergic junction of the sympathetic nerve with the medial smooth muscle of the cat nictitating membrane, blocking of the reuptake of noradrenaline with phenoxibenzamine suppressed the amplitude of rhythmic excitatory synaptic potentials. Stimulation of postganglionic sympathetic nerve (10/sec) made the time constant of the first component of the potential 60 sec whereas that of the second component--600 sec. The depression of amplitude seems to be connected with possible decrease in the noradrenaline release and partial exhaustion of its storage. The analysis of the transmitter function showed the release of noradrenaline to a single impulse to be in the reverse relation to the stimulation frequency and at 10/sec to constitute about 3 x 10(-4) (at 20/sec -1.9 X 10(-4)) of the transmitter storage. The replenishment of the transmitter (4 x 10(-6) of the initial operating pool of noradrenaline to a single impulse at 10/sec) was intensified parallel to the increased frequency of adrenergic neurons firing and was able to provide for afferent synaptic transmission within the working frequencies of the afferent part of the sympathetic reflex arch.

[Monosynaptic reflexes of the cat spinal cord during the development of insulin hypoglycemia]. / Monosinapticheskie refleksy spinnogo mozga koshek pri razvivaiushcheisia insulinovoi gipoglikemii.

Insulin-induced hypoglycemia caused depression of rhythmic monosynaptic EPSP motoneurons of the lumbar cord in acute experiments on narcotized and spinal cats. It was demonstrated that growing depression of monosynaptic transmission was associated with the exhaustion of mediator operative fraction and not with any pre- or postsynaptic delay or inhibition over a period of initial hypoglycemia when the sugar content in the blood fell to the level of 50--60 mg%. The function disturbance of postsynaptic formations of monosynaptic reflex arc of spinal cord occured in more advanced hypoglycemia.

[Microiontophoretic study of the effect of acetylcholine and noradrenaline on the monosynaptic reflex activity of the spinal cord]. / Mikroionoforeticheskoe izuchenie vliianiia atsetilkholina i noradrenalina na monosinapticheskuiu reflektornuiu deiatel'nost' spinnogo mozga.

In anesthetized and spinal cats the influence of microionophoretic local injections of acetylcholine and noradrenaline into different layers of grey substance of lumbar segments of the spinal cord were studied with aid of monosynaptic EPSPs of motoneurons. Injections of ACH and NA in the surface layers of the grey substance of dorsal horn induced depression of monosynaptic reactions. In the area of 6--7 layers ACH induced a weak depression, while NA significantly increased the reflex responses. In the given arrangement of motoneurons NA depressed and ACH facilitated extensor and flexor monosynaptic reactions of motoneurons.

[Mechanisms of inhibition of synaptic transmission in the sympathetic ganglia of rats with alloxan diabetes]. / O mekhanizmakh ugneteniia sinapticheskoi peredachi v simpaticheskikh gangliiakh krys pri alloksanovom diabete.

In experiments on the isolated superior cervical sympathetic ganglia of rats with alloxan diabetes rhythmic stimulation of preganglionic nerves was effected; summation presynaptic spikes and EPSPs of ganglionic neurons were registered. In rats with moderately severe alloxan diabetes progressive depression of rhythmic ganglion potentials was connected with suppression of the mediator emission to the impulse due to rapid exhaustion of its operational fraction. Rats with severe diabetes displayed also postsynaptic suppression of the ganglionic neurons. Dynamic characteristics of the transmitter turnover assessed on the basis of consideration of the successive patterns of posttetanic potentiation showed insignificant changes in the mediator output and a significant (by 38%) suppression of the mediator reserve per sec in comparison with control.