Effects of kainic acid on synaptic transmission in skate electroreceptors (ampullae of Lorenzini)

The effects of kainic acid on synaptic transmission in electroreceptors were investigated in the skate using techniques of uninterrupted superfusion of the synaptic area with a solution containing this substance and then recording the spike activity of single nerve fibers of the ampullae of Lorenzini. Kainic acid at threshold concentrations of the order of 10^–9 M effectively changed spontaneous and evoked activity of the receptors. Level of background activity served as an indication of the effects taking place. During blockage of synaptic transmission produced by magnesium ions the addition of kainic acid to the magnesium-saturated solution restored both spontaneous and evoked activity. It was deduced that the action of kainic acid on skate electroreceptors is of a primarily presynaptic nature.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 18, No. 2, pp. 147–153, March–April, 1986.     

Inhibition of jaw opening reflexes by stimulation of the central gray matter and raphe nuclei in cats

The effect of stimulation of the mesencephalic central gray matter and raphe nuclei on jaw opening reflexes evoked by excitation of high-threshold (dental pulp) and low-threshold (A-alpha) fibers of the infraorbital nerve afferents was studied in cats anesthetized with chloralose and pentobarbital. The jaw opening reflex evoked by stimulation of the dental pulp was shown to be effectively suppressed by conditioning stimulation of the central gray matter and raphe nuclei. The reflex evoked by stimulation of low-threshold infraorbital nerve afferents also was depressed (but less deeply and for a shorter period than the reflex evoked by stimulation of the dental pulp) during stimulation of the raphe nuclei and caudal zone of the central gray matter, but was unchanged after stimulation of the points located in the rostral zone of the central gray matter. Application of single stimuli or bursts of five stimuli with a frequency of 100 Hz had no effect on the reflexes studied. Short-term stimulation with a burst of 10–20 stimuli with a following frequency of 200–400 Hz led to inhibition of the reflexes, which lasted 450–1000 msec. Long-term stimulation of the central gray matter and raphe nuclei for 30 sec with a frequency of 50 Hz caused inhibition of jaw opening reflexes evoked by stimulation of both high- and low-threshold afferents for 60 min. Impulses from the central gray matter and raphe nuclei thus have a mainly inhibitory action on the jaw opening reflex evoked by stimulation of high-threshold afferents, but they act less effectively on the reflex evoked by stimulation of low-thres-hold afferents. The duration of inhibition depends essentially on the parameters of stimulation.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 16, No. 3, pp. 374–387, May–June, 1984.     

Comparison of synaptosomal and glial uptake of pipecolic acid and GABA in rat brain

The active uptake of [³H]pipecolic acid increased with incubation time and its uptake at 3 min was half of that at 20 min. [¹⁴C]GABA uptake rose earlier, and its uptake at 3 min was almost 80% of that at 20 min. On the other hand, a ratio (pellet/medium) of [³H]pipecolic acid uptake into glial cell-enriched fractions, was much less (0.4–0.6) than that of [¹⁴C]GABA (25.8–74.1). GABA, 10^–4 M, and pipecolic acid, 10^–4 M, produced a significant inhibition of [³H]pipecolic acid uptake into P₂ fractions. Pipecolic acid, 10^–4 M, significantly reduced the synaptosomal and glial uptake of [¹⁴C]GABA. GABA, 10^–4 M, affected neither spontaneous nor high K⁺-induced release of [³H]pipecolic acid from brain slices. It is suggested that pipecolic acid is involved in either synaptic transmission or in its modulation at GABA synapses in the central nervous system.     

Relations between spontaneous and evoked unit activity in the cat auditory cortex during defensive conditioning to acoustic stimulation

Spontaneous and evoked unit activity in the auditory cortex of waking cats was studied during defensive conditioning. An increase in the frequency of spontaneous activity arising under these circumstances in many neurons was frequently observed after presentation of the first combinations (before the appearance of effector responses), and reached its highest probability after thirty combinations (parallel with the appearance of conditioned-reflex motor responses). Comparison of the mean frequencies of spontaneous activity and the corresponding evoked activity reveals, on the one hand, a nonlinear relationship between them and, on the other hand, dominance of responses of activation type and weaker representation of inhibitory responses. Several levels of spontaneous activity were discovered, corresponding to particular zones of mean frequencies of evoked activity. Analysis of spontaneous activity before and after presentation of the conditioned stimulus (the after-period) showed that the mean frequencies in both these periods were very similar in the case of a stable conditioned reflex. In that case preservation of the structure of the spike train of several neurons was observed for stable time intervals (ranging from tens of minutes to 1–3 h).A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 12, No. 3, pp. 227–238, May– June, 1980.     

Principle of neuronal organization of defensive reflexes in mollusks

Spontaneous and evoked synaptic activity of command neurons for the defensive response of spiracle closing were studied by simultaneous intracellular recording of activity of several identified CNS neurons in snails. Comparison of monosynaptic EPSPs in command neurons evoked by discharges of presynaptic neurons with spontaneous synaptic potentials indicated that the central organization of the defensive reflex is in the form of a two-layered neuron net in which each neuron of the afferent layer possesses a local receptive field, but which overlaps with other afferent neurons. Each neuron of the afferent layer is connected with each neuron of the efferent layer by monosynaptic excitatory connections that differ in efficiency (maximal only with one neuron of the efferent layer). Both receptive fields of neurons of the afferent layer and "fields of efficiency of synaptic connections" are distributed according to the normal law. As a result of this organization the neuron net acquires a new quality: The action of different stimuli leads to the appearance of differently located "spatial excitation profiles" of efferent layer neurons even when this action of the stimulus occurs not at the center of the receptive field.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 16, No. 1, pp. 26–34, January-February, 1984.     

Activity of sensorimotor cortex neurons during a dopaminergic transmission block in cats performing conditional reflex

Activity of sensorimotor cortex neurons was recorded in chronic experements on cats trained to perform instrumental conditional reflex; records were made before, during, and after isolated iontophoretic applications of haloperidol or glutamate, or their combined application. Haloperidol was shown either to facilitate or to inhibit the background and evoked (related to acoustic stimulation and motor response) spike activity of cortical neurons. Aftereffects of haloperidol were observed too; they were still expressed 10–15 min after the cessation of the iontophoresis. Combined haloperidol and glutamate application was followed by a sharp suppression of the evoked responses potentiated earlier by glutamate. An adenylatecyclase system is supposed to mediate the facilitation evoked by glutamate application. Some modulators, including dopamine, probably activate adenylatecyclase and in this way ensure facilitation of the glutamate-induced responses.Neirofiziologiya/Neurophysiology, Vol. 26, No. 5, pp. 347–355, September–October, 1994.     

Investigation of pallidofugal influences on hypothalamic activity

In chronic experiments on nine cats electrical stimulation of the posterior zones of the lateral hypothalamus led to reproduction of a conditioned food-getting reflex produced previously in response to clicks. During stimulation of the globus pallidus a food-getting reflex also appeared in 3 of 10 zones studied, but it did so only irregularly. In response to combined stimulation of the hypothalamus and these three zones of the globus pallidus facilitation of this reflex was observed: its intensity was increased and its latent period shortened. Stimulation of other areas of the globus pallidus inhibited the food getting reflex of hypothalamic origin on account of the intensification of purposeless motor responses. Stimulation of the globus pallidus evoked desynchronization of spontaneous hypothalamic electrical activity. After bilateral electrolytic destruction of the globus pallidus and its principal efferent pathway (the ansa lenticularis) no conditioned food-getting reflex was reproduced during hypothalamic stimulation. After pallidectomy the amplitude of the spontaneous waves and evoked potentials was reduced by a statistically significant degree in the hypothalamic zones tested. The results are evidence of the existence of regulatory functional influences of the globus pallidus on the lateral hypothalamus.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 6, No. 6, pp. 592–601, November–December, 1974.     

Dynamics of single unit activity in the association cortex of waking cats during defensive conditioning

Responses of neurons in association area 5 during defensive conditioning to acoustic stimulation were studied in chronic experiments on cats. As a rule the neurons responded by excitation to presentation of conditioned and unconditioned stimuli. During the conditioned reflex unit responses usually appeared in the first 50 msec after the beginning of acoustic stimulation, i.e., they were connected with the action of the conditioned stimulus and not with manifestations of conditioned-reflex motion. The most significant changes in responses of cortical association units were observed in the initial period of conditioning. During stabilization of the conditioned reflex, responses of some neurons became stabilized, whereas in other neurons the spontaneous activity and intensity of responses increased, and in a third group the response to one of the stimuli disappeared. This last result indicates a switch during conditioning from polysensory unit responses to monosensory specialized responses. Extinctive inhibition was found to consist of a gradual decrease in the level of the spike discharge and its approximation to spontaneous activity, i.e., to be passive in character.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 10, No. 6, pp. 563–572, November–December, 1978.     

Selective involvement of non-histone chromatin proteins in the reproduction of averse reaction to food in snail

Participation of the brain-specific non-histone chromatin proteins Np-3.5 in the reproduction of an averse habit to certain kind of food was studied in experiments onHelix lucorum. Antibodies to these proteins were found to completely suppress the behavioral reactions and responses of the defensive behavior command neurons evoked by a presentation of a certain conditioning stimulus: a carrot. The action of the antibodies was specific, as they did not change the snail's reactions to presentation of another conditioning stimulus: an apple. The effect developed 1.5 h after the administration of antibodies to Np-3.5, and remained for 80–110 min, with subsequent complete restoration of the conditioned reflex. The antibodies to Np-3.5 did not affect the nutritive behavior of untrained snails. The antibodies to Np-3.5 were found to label cytoplasm in the command neurons, whereas in the snails trained to reject carrot the label appeared in the nuclei of the cells. It has been suggested that the Np-3.5 proteins selectively participate in the molecular-genetic processes responsible for neurophysiological mechanisms of an information draw from the long-term memory.     

电刺激大鼠巨细胞网状核对小脑浦肯野细胞自发和诱发电活动的影响

本研究在麻醉并制动的大鼠上观察了电刺激巨细胞网状核(Gi)对小脑浦肯野细胞(PC)自发及诱发简单锋电位的影响。结果如下:(1)刺激Gi可使PC的简单锋电位出现潜伏期小于20ms的抑制性或兴奋性反应,并以抑制性反应为主。抑制性反应持续40-100ms,而兴奋性反应的时程可达200ms以上;(2)注射5-HT_2型受体阻断剂methysergide可以减弱或阻断电刺激Gi对PC自发简单锋电位的抑制作用;(3)条件性Gi刺激可以显著压抑或加强由刺激对侧大脑皮层感觉运动区引起的PC诱发简单锋电位反应。以上结果说明:在大鼠存在Gi-小脑通路,这一通路中的部分纤维是5-HT能的。Gi-小脑纤维可能通过突触和/或非经典突触的化学传递方式对PC的电活动产生某种调制性的影响。推测Gi-小脑传入纤维投射可能在某些小脑功能活动,如肌紧张及姿势的调节等方面发挥重要作用。     

Depression of evoked potentials in rat thalamic ventro-basal complex and somatosensory cortex after reticular stimulation

Experiments on unanesthetized rats immobilized with D-tubocurarine showed that electrical stimulation (100/sec) of the central gray matter and the mesencephalic and medullary reticular formation considerably depressed potentials in the somatic thalamic relay nucleus and somatosensory cortex evoked by stimulation of the forelimb or medial lemniscus. The mean threshold values of the current used for electrical stimulation of these structures did not differ significantly and were 70 (20–100), 100 (20–120), and 120 (50–200) µA, respectively. On comparison of the amplitude-temporal characteristics of inhibition of evoked potentials during electrical stimulation of the above-mentioned structures by a current of twice the threshold strength, no significant differences were found. Immediately after the end of electrical stimulation the amplitude of the cortical evolved potential and the post-synaptic components of the thalamic evoked potential was 50–60% (P<0.01) below the control values. The duration of this depression varied from 0.5 to 1 sec. An increase in the intensity of electrical stimulation of brain-stem structures to between three and five times the threshold led to depression of the presynaptic component of the thalamic evoked potential also. Depression of the evoked potential as described above was found with various ratios between the intensities of conditioning and testing stimuli.M. V. Lomonosov Moscow State University. Translated from Neirofiziologiya, Vol. 8, No. 5, pp. 467–475, September–October, 1976.     

Ultrasound-induced changes in synaptic processes with different transmitters in smooth muscles

The effect of therapeutic-intensity ultrasound on neuromuscular transmission and spontaneous electrical and contractile activity in smooth muscles of the gastrointestinal tract of guinea pig was studied by a modified sucrose-gap technique. The action of ultrasound was found to facilitate the acetylcholinergic neuromuscular transmission (mainly by increasing the amplitude of excitatory postsynaptic potentials). The higher efficiency of the nonadrenergic neuromuscular transmission was manifested as an increase (nearly twofold) in the total duration, but not in the amplitude, of inhibitory postsynaptic potentials. Modulations of the first and second components of the potentials caused respectively by the action of ATP and of nitric oxide as possible transmitters, were different. Concurrently with enhancing the synaptic transmission efficiency, ultrasound exerted an opposite, inhibitory, effect on generation of spontaneous action potentials and contraction of smooth muscles. All the ultrasound effects were fully reversible. The findings permit assuming a special mechanism of modification of the synaptic transmission in smooth muscles under the action of ultrasound.Neirofiziologiya/Neurophysiology, Vol. 25, No. 4, pp. 297–302, July–August, 1993.     

Inhibitory effect of dopamine on the transmission of excitation in isolated rat spinal cord

The effects of dopamine on ventral root potential produced by a single supramaximal dorsal root stimulation of the dorsal root was investigated during experiments on isolated superfused spinal cord segments from 10–16-day old rats. A reciprocal dose-dependent inhibition of the mono- and polysynaptic components of reflex response was also observed. Minimum effective concentration was 1×10^–8 M dopamine. Extent of reflex response increased in step with dopamine concentration, so that the amplitude of the monosynaptic component of ventral root potential was decreased by 20% and 87% of baseline level by the action of 10^–4 and 10^–3 M dopamine respectively on the cord. The amplitude of the polysynaptic component was thereby decreased by an average of 18% and 87%. Findings indicate that dopaminergic brainstem-spinal pathways contribute to the governing of impulse transmission in the segmental reflex arcs. Inhibition of dopaminergic synaptic transmission probably underlies the increase in latency already described in the literature, as well as the increase observed in the threshold of reflex motor response to nociceptive action following either stimulation of the dopaminergic brainstem structures or intravenous administration of dopamine agonists.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 18, No. 5, pp. 616–621, September–October, 1986.     

Responses of somatic cortical neurons during the conditioned placing reflex in cats

Unit activity was studied in areas 3 and 4 during the conditioned placing reflex in cats. Responses of somatic cortical neurons in this case were shown to develop comparatively late — 80–100 or, more often, 200–450 msec after the conditioned stimulus. In the motor cortex responses preceded movement by 50–550 msec, whereas in the somatosensory cortex they usually began simultaneously with or after the beginning of the movement. Judging from responses of somatic cortical neurons, the placing reflex is realized by the same neuronal mechanism as the corresponding voluntary movement. The differential stimulus and positive conditioned stimulus, after extinction of the conditioned placing reflex, evoked short-latency spike responses lasting 250–350 msec in the same neurons as took part in the reflex itself. In these types of internal inhibition, responses of the neurons were thus initially excitatory in character. Participation of the neurons in the conditioned placing reflex and its extinction, disinhibition, and differentiation, is the result of a change in the time course of excitatory processes and is evidently connected with differential changes in the efficiency of the various synaptic inputs of the neuron.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 14, No. 4, pp. 392–401, July–August, 1982.     

Neurochemical mechanisms in inhibitory effects of stimulation of the periaqueductal gray matter on high-threshold reflex activity of the reticular formation

A study was made of microinjections of antagonists of various neuromodulators on the dynamics of inhibition of the spino-bulbo-spinal reflexes which were evoked by stimulation of the central gray matter (PAG) in rats anesthetized with chloralose. Injections were made into the reticular gigantocellular nucleus (GN), which is the basic supraspinal center of this reflex. Administering methysergide (a blocker of serotonin receptors) was accompanied by significant (two to four times) diminution of inhibition evoked by PAG stimulation with a short, high-frequency series of stimuli. Long inhibition caused by long, rhythmic stimulation of the PAG was diminished less significantly: from 6–10 to 2.5–4 min. When the opiate receptors of the GN neurons were blocked with naloxone, duration of inhibition was reduced by two to five times. The most clearly expressed diminution of both types of inhibitions was noted with injections of haloperidol, an antagonist of catecholamines. Our data indicate that evidently all of these neuromediator (neuromodulator) systems participate in inhibition of high-threshold, reflex activity of the reticular formation evoked by stimulation of the PAG, but their participation in this process is unequal.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 23, No. 4, pp. 455–463, July–August, 1991.     

Temperature Differentially Facilitates Spontaneous but Not Evoked Glutamate Release from Cranial Visceral Primary Afferents

Temperature is fundamentally important to all biological functions including synaptic glutamate release. Vagal afferents from the solitary tract (ST) synapse on second order neurons in the nucleus of the solitary tract, and glutamate release at this first central synapse controls autonomic reflex function. Expression of the temperature-sensitive Transient Receptor Potential Vanilloid Type 1 receptor separates ST afferents into C-fibers (TRPV1+) and A-fibers (TRPV1-). Action potential-evoked glutamate release is similar between C- and A-fiber afferents, but TRPV1 expression facilitates a second form of synaptic glutamate release in C-fibers by promoting substantially more spontaneous glutamate release. The influence of temperature on different forms of glutamate release is not well understood. Here we tested how temperature impacts the generation of evoked and spontaneous release of glutamate and its relation to TRPV1 expression. In horizontal brainstem slices of rats, activation of ST primary afferents generated synchronous evoked glutamate release (ST-eEPSCs) at constant latency whose amplitude reflects the probability of evoked glutamate release. The frequency of spontaneous EPSCs in these same neurons measured the probability of spontaneous glutamate release. We measured both forms of glutamate from each neuron during ramp changes in bath temperature of 4–5°C. Spontaneous glutamate release from TRPV1+ closely tracked with these thermal changes indicating changes in the probability of spontaneous glutamate release. In the same neurons, temperature changed axon conduction registered as latency shifts but ST-eEPSC amplitudes were constant and independent of TRPV1 expression. These data indicate that TRPV1-operated glutamate release is independent of action potential-evoked glutamate release in the same neurons. Together, these support the hypothesis that evoked and spontaneous glutamate release originate from two pools of vesicles that are independently modulated and are distinct processes.     

Involvement of mesencephalic reticular formation neurons in cat conditioned reflexes

Traditional defensive and operant food reflexes were used to investigate neuronal responses of the mesencephalic reticular formation. It was found that these neurons may be divided into different groups according to function, depending on how they respond to positive conditioning stimuli. Of the two main groups of neurons with sustained tonic reactions one is activated in response to positive acoustic conditioning stimulation; it no longer reacts to the same stimulus after extinction of the reflex, while the other only becomes involved in response to positive stimulation accompanying the initiation of movement. Neurons belonging to the second group begin to respond directly to acoustic stimulation after extinction of the conditioned reflex. Neurons of the mesencephalic reticular formation can thus exercise additional tonic ascending effects both in the production and inner inhibition of the conditioned reflex. The group of neurons with a phasic reaction, i.e., a double response (a direct response to sound and another produced by movement) displayed a drop in spontaneous activity during the shaping of inhibition of differentiation and of extinction in particular. It was found that the initial changes in the spike response of reticular formation neurons during conditioning and pseudo-conditioning are similar. There are thus grounds for stating that neurons of the mesencephalic reticular formation participate in the shaping, production, and inner inhibition of traditional and operant conditioned reflexes in a differentiated capacity rather than as a population reacting identically.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 18, No. 2, pp. 161–171, March–April, 1986.     

Posttetanic changes in hippocampal minimal evoked potentials

Changes in the EEG induced by a single spike were recorded in the hippocampus of an unanesthetized rabbit. Summation of focal electrical activity synchronous with spontaneous single unit discharges at the symmetrical point of contralateral hemisphere revealed no stable potentials which could reflect these changes. In two cases discharges identified as activity of Shaffer's collaterals were recorded in area CA₁. Summation of post-spike changes in evoked activity recorded by the same microelectrode showed stable negative waves with an amplitute of 40–60 µV, which could have been evoked by single spikes. The curve of amplitude of the averaged evoked potentials versus near-threshold current strength stimulating the intrahippocampal pathways was not smooth in most experiments but stepwise in character. It is suggested that the minimal evoked potential corresponding to the first step (amplitude 40–80 µV) reflects a response to stimulation of one fiber. After above-threshold tetanization prolonged posttetanic potentiation of the minimal evoked potentials did not arise in CA₁ in response to stimulation of Shaffer's collaterals. Minimal evoked potentials recorded in area CA₃ in response to stimulation of the dentate fascia showed clear potentiation. The results are in agreement with the hypothesis of the synaptic localization of the mechanisms responsible for prolonged posttetanic potentiation.Brain Institute, Academy of Medical Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 9, No. 2, pp. 124–134, March–April, 1977.     

Contribution of a humoral factor to postsynaptic sensitization in heterosynaptic facilitation

It was shown that heterosynaptic facilitation develops in the cerebral ganglia giant neurons of the freshwater gastropod molluskPlanorbis corn eus due to diffuse neurohumoral influences on pre- and postsynaptic structures and not local synaptic action on presynaptic mechanisms. It was also found that n-cholinergic synaptic mechanisms come under this facilitatory influence. Serotonin is the source of facilitation in neurons of bothPlanorbis corneus cerebral ganglion and those of the aplysia abdominal ganglion. Seeing that: a) conditioning stimuli facilitate the effects produced by iontophoretic acetylcholine application, as well as n-cholinergic synaptic transmission and b) the amplitude of EPSP and acetylcholine potential increase 4–6 times during facilitation when the input impedance of the post-synaptic membrane is increased by just 20%, it was deduced that the postsynaptic membrane of the giant neuron makes a significant contribution to heterosynaptic facilitation of the sensitization of n-cholinergic receptors. The part played by n-cholinergic receptors of the postsynaptic membrane in heterosynaptic facilitation and conditioned reflex habituation is discussed.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 18, No. 2, pp. 250–259, March–April, 1986.     

Monosynaptic excitory postsynaptic potentials in thoracic motoneurons under reticulospinal influences

We studied synaptic processes in motoneurons of thoracic segments (T_IX-T_XI) evoked by stimulation of the medial area of the giant-cell reticular nucleus in decerebrated cats. Monosynaptic EPSP were recorded in the majority of investigated motoneurons upon activation of the most rapidly conducting reticulospinal fibers. In some cells, such monosynaptic EPSP were accompanied by late EPSP or IPSP. Amplitude of monosynaptic EPSP attained 5 mV, but this value usually was insufficient for development of an action potential. Upon summation of single monosynaptic EPSP, the membrane potential reached the critical level and an action potential arose in the motoneuron. The efficiency of summary processes evoked by stimulation of the reticular formation exceeded the intensity of synaptic processes that arise in thoracic motoneurons on stimulating the nucleus of Deiters. Functional characteristics of reticular and vestibular monosynaptic EPSP are discussed in the work.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 1, No. 3, pp. 243–252, November–December, 1969.