Responses of auditory medullary units to sinusoidally amplitude-modulated tones in frogs

Spike discharges of medullary units ofRana ridibunda in response to tones of optimal frequency for the neuron, with sinusoidal amplitude modulation, was studied. Reproduction of sound modulation in unit activity was assessed by the use of phase histograms of responses corresponding to the period of modulation. Amplitude modulation was reproduced in the firing pattern of neurons of the dorsal nucleus over a wide range of modulation frequencies and carrier levels. Accentuation of small changes of amplitude for modulation frequencies of 70–150 Hz was observed in many neurons of the superior olives. The phase of the response was a linear function of modulation frequency both in the dorsal nucleus and in the superior olives. The greatest enhancement of amplitude changes corresponded to low modulation indices.Academician N. N. Andreev Acoustics Institute, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 17, No. 3, pp. 390–396, May–June, 1985.     

Rhythmic activity evoked by adequate stimulation in the fish retina

The distribution of evoked rhythmic responses on the surface and in the depths of the retina of the carp (Cyprinus carpio) and tench (Tinca tinca) and the dependence of the amplitude — frequency characteristics of the response on stimulus intensity and duration were investigated by recording the local electroretinogram and unit activity of the ganglion cells. Rhythmic on- and off-responses to light differed in various characteristics, including their distribution between the cellular and synaptic layers of the retina. The frequency, amplitude, and number of waves in the response were found to depend on the parameters of the stimulus. On-, off-, and on — off-ganglion cells were represented in the records. Their spike discharge usually corresponded to a phase angle of the negative half-wave of the rhythmic response of close to /2. The results of experiments in which conduction along the optic nerve was blocked by cold showed that the system of generation of the rhythmic response in the retina is under the tonic influence of the centers.M. V. Lomonosov Moscow State University. Translated from Neirofiziologiya, Vol. 9, No. 1, pp. 61–68, January–February, 1977.     

Electrophysiological investigation of central neurons of the electroreceptor system of the skate

Bioelectrical responses of acoustico-lateral neurons to electrical stimulation of the ampullae of Lorenzini were investigated in acute experiments on the anesthetized Black Sea skateTrigon pastinaca. Three types of responses were found: a primary composite response, prolonged activity, and single unit activity. Excitation of the neurons corresponded to a more marked negative phase, and inhibition to a more marked positive phase of the primary response. The thresholds of the unit responses to adequate electrical stimulation were 10^–9–10^–10 A/mm² and the minimal latent period 20 msec. The spontaneous activity of some neurons clearly depended on the animal's respiration. The character of the response depended on stimulus polarity, as reflected in the appearance of on- and off-responses. A tonic type of response with features of adaptation was predominant. The dependence of some response parameters (latent period of on- and off-responses, firing rate, duration of the contrast interval, response thresholds) on those of the stimulus is analyzed. The mechanisms of these bioelectrical responses are discussed.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol.6, No.1, pp.59–67, January–February, 1974.     

Electric reactions of the auditory cortex areas in bats to ultrasonic stimuli with various fill frequencies

The overall electric reactions and action potentials of single neurons in the auditory cortex were investigated for Vespertilionidae (Myotis oxygnathus) and Rhinolophidae (Rhinolophus ferrum equinum) narcotized with Hexenal. In the Vespertilionidae the greatest sensitivity to ultrasound is manifest at frequencies from 10 to 50 kHz, and in the Rhinolophidae for the ranges from 10 to 40 and from 82 to 84 kHz. The shapes of the response areas of single neurons in both types of bats are similar except for neurons discovered in Rhinolophidae that have three response areas with characteristic frequencies in the ranges 27–28, 40–42, and 80–84kHz. Narrow response areas with characteristic frequencies in the range from 70 to 90kHz appear on a considerable proportion of the neurons in the Rhinolophidae, but not the Vespertilionidae. Low thresholds are recorded to the stimulus cutoff in the range from 76 to 86 kHz.A. A. Zhdanov Leningrad State University. Translated from Neirofiziologiya, Vol. 3, No. 5, pp. 526–532, September–October, 1971.     

Mechanism of the "enhancing" response in the rabbit visual cortex

Mechanisms of the "enhancing" evoked potential arising in the visual cortex in response to repeated stimulation at intervals of 100–150 msec were investigated on unanesthetized rabbits. Such intervals correspond to the phase of postinhibitory activation caused by the first (conditioning) stimulus. It is shown that the enhancing response lasts slightly longer than the primary response to a single stimulus and develops upon stimulation of the optic nerve and subcortical white substance under the point of derivation. The enhancing response is accompanied by a high-amplitude excitatory postsynaptic potential in cortical neurons and by a burst of impulse activity. Hence it can be concluded that it is generated by excitatory synapses of cortical neurons. Characteristic features of the enhancing response are the relation between the duration of the response and its amplitude (the response is shorter, the higher its amplitude) and the weak effect of the intensity of the stimulus on the amplitude of the response. An analysis of the possible mechanisms of enhancement of the response when the stimulus evoking it coincides with the phase of postinhibitory activation leads to the suggestion that this response is generated by a recurrent excitatory intracortical system. This suggestion makes it possible to explain the ability of the response to be enhanced in the presence of postinhibitory activity and some other properties of it.A. N. Severtsov Institute of Evolutionary Animal Morphology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 2, No. 1, pp. 64–72, January–February, 1970.     

Unit responses of the torus semicircularis of frogs to acoustic stimuli of different duration

The action of tonal stimuli of a characteristic frequency but of varied duration on 76 neurons of the mesencephalic auditory center (the torus semicircularis) of the frogRana temporaria was investigated. Responses to short stimuli (10 msec) of five groups of neurons differentiated by their responses to a long (300 msec) stimulus, were studied. Responses of some neurons were strengthened on shortening of the stimulus, while others responded only to tones of longer than the critical duration; this critical duration is independent of stimulus intensity over a wide range. The possible synaptic mechanisms lying at the basis of the observed effects are discussed.Acoustic Institute, Moscow. Translated from Neirofiziologiya, Vol. 5, No. 1, pp. 13–20, January–February, 1973.     

Characteristics of electrical responses by the medial geniculate bodies in Vespertilionidae and Rhinolophidae to ultrasonic stimuli with different frequencies

The total electrical responses and action potentials of the neurons in the medial geniculate bodies in Vespertilionidae and Rhinolophidae were investigated. Maximum sensitivity to ultrasonic stimuli was recorded inMyotis oxygnathus (Vespertilionidae) in the range 10–40 kc/sec and 65–80 kc/sec, and in Rhinolophidae in the ranges 10–70 kc/sec and 81–86 kc/sec. Low thresholds were observed inMyotis oxygnathus for the frequencies covered by their echo-location cries, whereas the thresholds recorded in Rhinolophidae in the 80 kc/sec band (the principal frequency of their echo location cries) were 15–30 dB higher than those for adjacent frequencies. Minimum thresholds of off-responses were observed inMyotis oxygnathus in the range 50–60 kc/sec, and in Rhinolophidae in the range 78–80 kc/sec. The regions of neuronal response in both species of bat were generally similar in form to those of responses recorded in the medial geniculate bodies of other mammals. Some of the neurons in Rhinolophidae with a characteristic frequency of about 80 kc/sec were also sensitive to stimuli with one-half and one-third of the principal frequency. In Rhinolophidae the greatest selectivity for frequencies was possessed by neurons that responded within the range from 80 to 90 kc/sec.A. A. Zhadanov Leningrad State University. Translated from Neirofiziologiya, Vol. 3, No. 2, pp. 138–144, March–April, 1971.     

Analysis of evoked potentials of the cerebellar cortex

Evoked potentials (EP) of the cerebellar cortex in response to stimulation of peripheral nerves are characterized by a two-phase positive-negative oscillation of the potential having a latent period of 10–25 msec. The electropositive phase can contain up to three components. The latent period of component I comprises 3–9 msec. The latent period and amplitude of this component are distinguished by considerable stability, which indicates the predominant significance of presynaptic processes in its formation. The sign of component II changes at a depth of 500 µ (and more), which corresponds to the position of the granular cell layer. At this level there arises in the neurons a response with a latent period of 4–10 msec in the form of a group (3–10) of impulses with a frequency of up to 200 per sec. It is concluded that the granular cells participate in the formation of component II and partially participate in the formation of components I and III of the EP. Responses to stimulation of the nerves appear synchronously with the EP in 24% of responding Purkinje cells; they fall on the maximum electropositive deviation or component III of the EP. Microinjections of 1% strychnine into the cerebellar cortex cause an increase of EP amplitude; impulse activity of the neurons is intensified. This indicates participation of postsynaptic processes in the formation of EP. No shifts in the EP of the cerebellar cortex were observed after intracortical injection of 0.1% atropine.N. I. Pirogov Vinnitsa Medical Institute. Translated from Neirofiziologiya, Vol. 2, No. 4, pp. 429–433, July–August, 1970.     

Frequency tuning and response latencies at three levels in the brainstem of the echolocating bat,Eptesicus fuscus

To determine the level at which certain response characteristics originate, we compared monaural auditory responses of neurons in ventral cochlear nucleus, nuclei of lateral lemniscus and inferior colliculus. Characteristics examined were sharpness of frequency tuning, latency variability for individual neurons and range of latencies across neurons.Exceptionally broad tuning curves were found in the nuclei of the lateral lemniscus, while exceptionally narrow tuning curves were found in the inferior colliculus. Neither specialized tuning characteristic was found in the ventral cochlear nuclei.All neurons in the columnar division of the ventral nucleus of the lateral lemniscus maintained low variability of latency over a broad range of stimulus conditions. Some neurons in the cochlear nucleus (12%) and some in the inferior colliculus (15%) had low variability in latency but only at best frequency.Range of latencies across neurons was small in the ventral cochlear nucleus (1.3–5.7 ms), intermediate in the nuclei of the lateral lemniscus (1.7–19.8 ms) and greatest in the inferior colliculus (2.9–42.0 ms).We conclude that, in the nuclei of the lateral lemniscus and in the inferior colliculus, unique tuning and timing properties are built up from ascending inputs.Abbreviations AVCN anteroventral cochlear nucleus - BF best frequency - CV coefficient of variation - DCN dorsal cochlear nucleus - FM frequency modulation - IC inferior colliculus - NLL nuclei of lateral lemniscus - PSTH post stimulus time histogram - PVCN posteroventral cochlear nucleus - SD standard deviation - SPL sound pressure level - VCN ventral cochlear nuclei - VNLLc ventral nucleus of the lateral lemniscus, columnar division     

Interval-integration underlies amplitude modulation band-suppression selectivity in the anuran midbrain

We examined the mechanisms that underlie band-suppression amplitude modulation selectivity in the auditory midbrain of anurans. Band-suppression neurons respond well to low (5–10 Hz) and high (>70 Hz) rates of sinusoidal amplitude modulation, but poorly, if at all, to intermediate rates. The effectiveness of slow rates of sinusoidal amplitude modulation is due to the long duration of individual pulses; short-duration pulses (<10 ms) failed to elicit spikes when presented at 5–10 pulses s^–1. Each unit responded only after a threshold number of pulses (median=3, range=2–5) were delivered at an optimal rate. The salient stimulus feature was the number of consecutive interpulse intervals that were within a cell-specific tolerance. This interval-integrating process could be reset by a single long interval, even if preceded by a suprathreshold number of intervals. These findings indicate that band-suppression units are a subset of interval-integrating neurons. Band-suppression neurons differed from band-pass interval-integrating cells in having lower interval-number thresholds and broader interval tolerance. We suggest that these properties increase the probability of a postsynaptic spike, given a particular temporal pattern of afferent action potentials in response to long-duration pulses, i.e., predispose them to respond to slow rates of amplitude modulation. Modeling evidence is provided that supports this conclusion.Abbreviations AM amplitude modulation - PRR pulse repetition rate - SAM sinusoidal amplitude modulation     

Response of frog midbrain neurons to tones amplitude-modulated by pseudorandom noise

Spike response in torus semicircularis units to the effects of uninterrupted characteristic frequency tones amplitude-modulated by pseudorandom noise were investigated during experiments on immobilizedRana ridibunda. Period histograms of modulating waveform of 512 msec duration (both modulating polarities) were produced for 32 units. Almost all neurons investigated responded exclusively to the positive half of the modulating signal. Difference histograms obtained by calculating period histograms for different polarities of the envelope faithfully reproduced the dynamics of signal amplitude in four units. The remainder responded only to envelope maxima, without reproducing amplitude dynamics among these; over half the units represented only some of the envelope maxima, moreover. Certain cells were found which retained their specific pattern of response to pseudorandom noise over a wide range of carrier intensities.N. N. Andreev Acoustical Institute, Moscow. Translated from Neirofiziologiya, Vol. 22, No. 2, pp. 227–235, March–April, 1990.     

Serotonin-induced changes in the action of functionally distinct neurons in Helix pomatia

The effects of serotonin on the amplitude of summated EPSP in interneurons and on the duration of action potentials in sensory neurons, interneurons, and motoneurons involved in avoidance behavior were investigated in functionally distinct neurons isolated from theHelix pomatia nervous system. The duration of action potentials in sensory neurons was found to increase under the effects of serotonin (and this could underly the rise in EPSP amplitude), although that of interneuron and motoneuron spikes did not change. The functional significance of selective neuronal response to a rise in serotonin concentration is discussed, together with the mechanics underlying such effects.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 19, No. 3, pp. 316–322, May–June, 1987.     

Spatio-temporal convergence (STC) in otolith neurons

It has been recently demonstrated that some primary otolith afferents and most otolith-related vestibular nuclei neurons encode two spatial dimensions that can be described by two vectors in temporal and spatial quadrature. These cells are called broadly-tuned neurons. They are characterized by a non-zero tuning ratio which is defined as the ratio of the minimum over the maximum sensitivity of the neuron. Broadly-tuned neurons exhibit response gains that do not vary according to the cosine of the angle between the stimulus direction and the cell's maximum sensitivity vector and response phase values that depend on stimulus orientation. These responses were observed during stimulation with pure linear acceleration and can be explained by spatio-temporal convergence (STC) of primary otolith afferents and/or otolith hair cells. Simulations of STC of the inputs to primary otolith afferents and vestibular nuclei neurons have revealed interesting characteristics: First, in the case of two narrowly-tuned input signals, the largest tuning ratio is achieved when the input signals are of equal gain. The smaller the phase difference between the input vectors, the larger the orientation differences that are required to produce a certain tuning ratio. Orientation and temporal phase differences of 30–40° create tuning ratios of approximately 0.10–0.15 in target neurons. Second, in the case of multiple input signals, the larger the number of converging inputs, the smaller the tuning ratio of the target neuron. The tuning ratio depends on the number of input units, as long as there are not more than about 10. For more than 10–20 input vectors, the tuning ratio becomes almost independent of the number of inputs. Further, if the inputs comprise two populations (with different gain and phase values at a given stimulus frequency), the largest tuning ratio is obtained when the larger population has a smaller gain. These findings are discussed in the context of known anatomical and physiological characteristics of innervation patterns of primary otolith afferents and their possible convergence onto vestibular nuclei neurons.     

Unit responses of the inferior colliculi to changes in the intensity of an amplitude-modulated signal

Unit responses of the inferior colliculi of anesthetized rats to amplitude-modulated sounds during a change in the carrier intensity were investigated. The following unit response characteristics were assessed: the number of spikes in the response, the range of reproduction of the modulation frequency, the response duration, and the pattern of the spike response relative to the envelope of the amplitude-modulated stimulus. The following parameters of the stimulus were varied: carrier intensity (usually of optimal frequency or noise), frequency of modulation (from 2 to 100 Hz), and carrier frequency. With a decrease in the intensity of the carrier in the case of monotonic neurons, and also with an increase or decrease in the intensity of the carrier relative to its optimal level in nonmonotonic neurons, the following changes in the discharge were regularly observed: the number of spikes in the response and its duration were reduced down to the appearance of only one initial response, the range of reproduction of the rhythm of modulation was narrowed, and the response pattern was sharply modified.I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR. I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 5, No. 4, pp. 355–366, July–August, 1973.     

Effect of stimulus intensity on unit responses in the cat frontal cortex

Unit activity of the frontal cortex during changes in stimulus intensity in the near-threshold range (15–16 dB above the threshold for the combined evoked potential) was investigated by an extracellular recording method in acute experiments on cats anesthetized with chloralose (70 mg/kg). Comparative analysis of unit responses in specific (SI) and nonspecific projection areas revealed basically similar changes in pattern during an increase in stimulus intensity: A decrease in the latent period, an increase in the total frequency and the phasic character of the discharge, and an increase in the probability of response. However, a relatively stable latent period and probability of response were observed in specific projection neurons for a stimulus intensity of 3–5 threshold units, whereas for the nonspecific projection neurons it was observed for a stimulus intensity of 10–15 threshold units. All sensory projections in the frontal cortex are formed by two inputs: short-latency low-threshold and long-latency high-threshold. Analysis of modality-dependent differences in the threshold of sensitivity and the latent period of response of the polysensory neurons suggests that stimuli of different modalities converge directly on cortical neurons.A. A. Zhdanov Leningrad State University. Translated from Neirofiziologiya, Vol. 8, No. 6, pp. 606–612, November–December, 1976.     

Characteristics of electrical responses by cochlear nuclei in Vespertilionidae and Rhinolophidae to ultrasonic stimuli with various fill frequencies

The total electrical response and action potentials of separate neurons in the cochlear nuclei in Vespertilionidae and Rhinolophidae were investigated. Maximum sensitivity to ultrasound was recorded in Vespertilionidae in the frequency ranges 10–30 and 70–80 kc/sec, and in Rhinolophidae in the frequency ranges 10–30 and 84–86 kc/sec. Mininum off-response thresholds were observed in Vespertilionidae in the range 50–60 kc/sec, and in Rhinolophidae in the range 78–80 kc/sec. The areas of responses by neurons in the cochlear nuclei in both species of bats were similar in shape to those recorded in the same structure in other animals. An exception was provided by Rhinolophidae, in which three peculiar types of neurons were observed: 1) neurons whose response area lay in the frequency ranges up to 78 kc/sec or from 80 to 90 kc/sec; 2) neurons responding in the range 40–90 kc/sec, but not sensitive to stimuli with a fill frequency of 78–80 kc/sec; and 3) neurons whose response area lay in the range 78–80 kc/sec, but in which the character of the response changed from tonic to phasic when there was a change in the fill frequency of the stimulus. Maximum selectivity with regard to fill frequency of stimulus was observed in the neurons of Rhinolophidae in the frequency range 70–90 kc/sec.The term "fill frequency" can be rendered as frequency — Consultants Bureau.A. A. Zhdanov Leningrad State University. Translated from Neirofiziologiya, Vol. 3, No. 4, pp. 379–385, July–August, 1971.     

Effects of quinine on calcium current in mollusk neurons

The effects of quinine on the peak amplitude and the decay of calcium currents (I_Ca) were investigated in nonidentified neurons isolated fromHelix pomatia. A concentration of 1×10^–5–5×10^–4 M quinine was found to produce a reversible dose-dependent deceleration in the decline of I_Ca ("lead" effect) and a reversible, slowly evolving dose-dependent reduction in I_Ca amplitude ("lag" effect). A reduction in amplitude down to half control level is observed at a quinine concentration of 6 ×10^–5 M, while the current-voltage relationship of I_Ca shifts by 5–10 mV towards negative potentials. Results show that quinine successfully blocks calcium channels inHelix pomatia neurons.Institute of Brain Research, All-Union Mental Health Research Center, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 19, No. 3, pp. 413–417, May–June, 1987.     

Processing of behaviorally relevant temporal parameters of acoustic stimuli by single neurons in the superior olivary nucleus of the leopard frog

Summary Response characteristics of 130 single neurons in the superior olivary nucleus of the northern leopard frog (Rana pipiens pipiens) were examined to determine their selectivity to various behaviorally relevant temporal parameters [rise-fall time, duration, and amplitude modulation (AM) rate of acoustic signals. Response functions were constructed with respect to each of these variables. Neurons with different temporal firing patterns such as tonic, phasic or phasic-burst firing patterns, participated in time domain analysis in specific manners. Phasic neurons manifested preferences for signals with short rise-fall times, thus possessing low-pass response functions with respect to this stimulus parameter; conversely, tonic and phasic-burst units were non-selective and possessed all-pass response functions. A distinction between temporal firing patterns was also observed for duration coding. Whereas phasic units showed no change in the mean spike count with a change in stimulus duration (i.e., all-pass duration response functions), tonic and phasic-burst units gave higher mean spike counts with an increase in stimulus duration (i.e., primary-like high-pass response functions). Phasic units manifested greater response selectivity for AM rate than did tonic or phasic-burst units, and many phasic units were tuned to a narrow range of modulation rates (i.e., band-pass). The results suggest that SON neurons play an important role in the processing of complex acoustic patterns; they perform extensive computations on AM rate as well as other temporal parameters of complex sounds. Moreover, the response selectivities for rise-fall time, duration, and AM rate could often be shown to contribute to the differential responses to complex synthetic and natural sounds.Abbreviations SON superior olivary nucleus - DMN dorsal medullary nucleus - TS torus semicircularis - FTC frequency threshold curve - BF best excitatory frequency - PAM pulsatile amplitude modulation - SAM sinusoidal amplitude modulation - SQAM square-wave amplitude modulation - MTF modulation transfer function - PSTH peri-stimulus time histogram     

Ionic mechanisms underlying modulating effects of serotonin on acetylcholine-induced responses in Helix pomatia neurons

The ionic mechanisms underlying modulatory effects of serotonin on acetylcholine-response in identified and nonidentifiedHelix pomatia neurons were investigated using voltage-clamping techniques at the neuronal membrane. External application of 10^–5–10^–4 M serotonin to the membrane of neurons responding to application of acetylcholine depending on Na⁺ depolarization (D_Na response) reduced membrane conductivity during response to acetylcholine without changing reversal potential of acetylcholine-induced current. Acetylcholine (10^–6–10^–4 M) administration took place 1–3 min later. Neurons with response to acetylcholine application dependent on Cl⁺ depolarization (D_Cl response) or hyperpolarization (H_Cl response) behaved similarly. Analogous effects could be produced by external application of theophylline which, together with the latency and residual effect characteristic of serotonin action points to the participation of intracellular processes associated with the cellular cyclase system in the changes produced by serotonin in acetylcholineinduced response. Serotonin brought about a shift in reversal potential and an increase in the acetylcholine-induced current in those neurons where this response was associated with changed permeability at the membrane to certain types of ions. During two-stage acetylcholine-induced response of the D_Na-H_K type, serotonin inhibited the inward current stage. Mechanisms underlying modulatory serotonin action on acetylcholine-induced response in test neurons are discussed in the light of our findings.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 20, No. 1, pp. 57–64, January–February, 1988.     

Effects of cAMP on calcium currents in mollusk neurons differing in the sensitivity of their calcium conductance to serotonin action

The effects of cAMP and serotonin (5-HT) on calcium current (I_Ca) were investigated inHelix pomatia neurons using voltage clamp and intracellular perfusion techniques. Three types of neuronal response to extracellular application of 5-HT (1–10 µM) were found: reversible blockage of calcium conductance, absence of response, and increase in I_Ca amplitude. Intracellular application of exogenous cAMP was also found to produce an increase in I_Ca in cells stimulated by 5-HT action. Effects of 5-HT and cAMP were non-additive under these circumstances and were potentiated equally by cyclic nucleotide phosphodiesterase inhibitor. Applying cAMP led to no noticeable increase in I_Ca amplitude in cells with calcium conductance unchanged or blocked by 5-HT. Findings would indicate that the stimulating action of 5-HT is mediated by a rise in intracellular level of cAMP. It is postulated that two types of calcium channels differing in their dependence on cAMP metabolism exist; the presence of cAMP-dependent calcium channels at the neuronal membrane fits in with a certain type of 5-HT receptor also present in the cell, moreover. A new approach is suggested for research on isolated neurons, i.e., that of functional identification.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 22, No. 5, pp. 605–512, October–September, 1990.