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1.
Nikitin NI Varfolomeev AL Kotelenko LM 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2003,89(6):625-638
Unit responses in the primary auditory cortex of anesthetized cats to stationary and apparently moving stimuli resulted from a static and dynamically varying interaural delay (ITD) were recorded. The static stimuli consisted of binaurally presented tones and clicks. The dynamic stimuli were produced by in-phase and out-of-phase binaurally presented click trains with time-varying ITD. Sensitivity to ITDs was mostly seen in responses of the neurons with low characteristic frequency (below 2.8 kHz). All cells sampled with static stimuli responded to simulated motion. A motion effect could take the form of a difference in response magnitude depending on the direction of stimulus motion and a shift in the ITD-function opposite the direction of motion. The magnitude of motion effects was influenced by the position of motion trajectory relative to the ITD-function. The greatest motion effect was produced by motion crossing the ITD-function slopes. 相似文献
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The characteristics of extra- and intracellular responses of neurons in the AI region were studied in experiments with unanesthetized cats. It was established that auditory cortex neurons with similar best frequencies showed different forms of responses to tones of the corresponding frequency. About 40% of the auditory cortex neurons generated on responses to tone presentation. On — off and off responses were found in 27% of the neurons. Cortical neurons (27%) in which stimulation or inhibition of impulse discharge persisted throughout tone action were assigned to the tonic type group of cells. Approximately 6% of neurons in the AI region did not respond to a tone. During intracellular recording about 85% of the neurons responded to the turning on and/or off of a tone by generating an action potential followed by an IPSI. In 96% of the cortical neurons studied the IPSPs were a constant component of the intracellular responses to a tone. It is concluded that the inhibition of the impulse activity of the given neurons is of primarily a postsynaptic origin. Neurons showing one or another form of response differ from one another in the relative intensity and time characteristics of excitatory and inhibitory processes interacting on their postsynaptic membranes. In neurons of the phasic type inhibitory processes are dominant over excitatory, while excitatory processes are predominant in neurons of the tonic type.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 17, No. 4, pp. 500–508, July–August, 1985. 相似文献
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I. A. Vartanyan 《Neurophysiology》1975,7(6):466-470
Responses to frequency-modulated stimuli of 118 inferior collicular neurons were compared with quantitative characteristics of the frequency — threshold curves and lateral inhibitory zones during time-varying two-tone stimulation in anesthetized albino rats. In one third of neurons high sensitivity to the direction of frequency modulation does not correspond to their spatial characteristics (the shape, width, and arrangement of the lateral inhibitory zones relative to the frequency — threshold curve). The specificity of response of these neurons to a particular direction of frequency modulation is evidently based on differences in the temporal course of inhibition evoked by high-frequency and low-frequency tones.I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 7, No. 6, pp. 603–607, November–December, 1975. 相似文献
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Interaction between neurons with a tonic response pattern and either nearby or further removed (by about 400–500 µm) cortical neurons was investigated during acute experiments on 15 immobilized cats using cross-correlation analysis techniques. Synchronizing excitatory input common to the nerve cells was found in cross-correlation histograms (CCH) in 26 out of 36 test pairs of neurons (72%). Both positive and negative cross-correlation (five pairs in each case) were discovered, pointing to mono- or polysynaptic excitatory and inhibitory effects of the tonic neuron on spike activity in the other cell from CCH of 10 pairs of neurons. The functional diversity of neurons f distinguished by a tonic pattern of response to sound was deduced on the basis of findings from this research. The theory that some tonic type cells act as excitatory neurons and others fulfil the function of inhibitory interneurons is examined.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 21, No. 5, pp. 613–620, September–October, 1989. 相似文献
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D. K. Khachvankyan A. B. Sharambekyan G. G. Grigoryan A. G. Harutiunian J. A. Kozak S. A. Aramyan B. A. Harutiunian-Kozak 《Neurophysiology》2006,38(1):53-62
We examined responses of neurons of the field 21b of the cat brain cortex to presentation of moving visual stimuli of different
forms. Characteristics of the responses of about 54% of the studied neurons showed that in these cases configurations of the
contours of moving stimuli were to a certain extent discriminated. Most neurons selectively reacting to changes in the form
of the stimulus were dark-sensitive units (they generated optimum responses to presentation of dark visual stimuli on the
light background). Detailed examination of the spatial infrastructure of receptive fields (RFs) of the neurons and comparison
of this structure with the selectivity of neuronal responses showed that there is no significant correlation between static
organization of the RF and responses of the neuron to the movements of stimuli of different forms. We hypothesize that the
dynamic infrastructure of the RF and the combined activity of functional groups of neurons, whose RFs spatially overlap the
RF of the neuron under study, play a definite role in the mechanisms responsible for neuronal discrimination of the form of
the visual stimulus.
Neirofiziologiya/Neurophysiology, Vol. 38, No. 1, pp. 61–71, January–February, 2006. 相似文献
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We investigated the visual-cortex neurons of the conscious rabbit during simultaneous stimulation with a clicking sound and a light flash (complex) and during separate application of these stimuli. We tested the development of the reflex with time and of the sound-light association during prolonged rhythmic application of the sound and light. Fifty visual-cortex neurons were studied; 20% of the cells responded with a specific phased reaction and 16% exhibited a specific response to the complex different from the responses to each of its components. Development of a sound-light association was observed in 18% of the cells and a temporal reflex was induced in 25%. In most cases, the conditioned reaction evoked was similar to some informational element in the neuronal response to the complex.M. V. Lomonosov Moscow State University. Institute of Cybernetics, Academy of Sciences of the GruzSSR. Translated from Neirofiziologiya, Vol. 2, No. 4, pp. 391–398, July–August, 1970. 相似文献
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A. N. Tal'nov 《Neurophysiology》1985,17(4):393-402
The responses of motor cortex neurons in the cat to the presentation of a single auditory click and a series of 10 clicks presented with 1,000/sec frequency were studied under conditions of chronic experiments before and after the development of an instrumental food reflex. After reflex development a single presentation of a positive conditioned stimulus (single click) markedly influenced for 7 sec the appearance of instrumental movements. At the same time, the immediate responses of motor cortex neurons to presentation of the conditioned auditory stimulus had no impact on the appearance in the motor cortex of discharges leading to the realization of instrumental movements. Consequently, motor cortex neurons do not require activation from afferent sensory inputs for the generation of such discharges. The immediate neuronal responses to conditioned stimulation did not inhibit the realization of the instrumental reflex. It is proposed that they are associated with the realization of motor function in the unconditioned defensive response evoked by the presentation of an auditory stimulus. The presence or absence of responses to auditory conditioned stimulation was dependent upon the signal meaning of the stimulus, its physical parameters, and the degree of excitability of the animal.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 17, No. 4, pp. 539–550, July–August, 1985. 相似文献
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To form a coherent percept of the environment, our brain combines information from different senses. Such multisensory integration occurs in higher association cortices; but supposedly, it also occurs in early sensory areas. Confirming the latter hypothesis, we unequivocally demonstrate supra-additive integration of touch and sound stimulation at the second stage of the auditory cortex. Using high-resolution fMRI of the macaque monkey, we quantified the integration of auditory broad-band noise and tactile stimulation of hand and foot in anaesthetized animals. Integration was found posterior to and along the lateral side of the primary auditory cortex in the caudal auditory belt. Integration was stronger for temporally coincident stimuli and obeyed the principle of inverse effectiveness: greater enhancement for less effective stimuli. These findings demonstrates that multisensory integration occurs early and close to primary sensory areas and--because it occurs in anaesthetized animals--suggests that this integration is mediated by preattentive bottom-up mechanisms. 相似文献
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J. P. Ewert E. M. Framing E. Schürg-Pfeiffer A. Weerasuriya 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1990,167(4):495-508
The concept of coded 'command releasing systems' proposes that visually specialized descending tectal (and pretectal) neurons converge on motor pattern generating medullary circuits and release--in goal-specific combination--specific action patterns. Extracellular recordings from medullary neurons of the medial reticular formation of the awake immobilized toad in response to moving visual stimuli revealed the following main results. (i) Properties of medullary neurons were distinguished by location, shape, and size of visual receptive fields (ranging from relatively small to wide), by trigger features of various moving configural stimulus objects (including prey- and predator-selective properties), by tactile sensitivity, and by firing pattern characteristics (sluggish, tonic, warming-up, and cyclic). (ii) Visual receptive fields of medullary neurons and their responses to moving configural objects suggest converging inputs of tectal (and pretectal) descending neurons. (iii) In contrast to tectal monocular 'small-field' neurons, the excitatory visual receptive fields of comparable medullary neurons were larger, ellipsoidally shaped, mostly oriented horizontally, and not topographically mapped in an obvious fashion. Furthermore, configural feature discrimination was sharper. (iv) The observation of multiple properties in most medullary neurons (partly showing combined visual and cutaneous sensitivities) suggests integration of various inputs by these cells, and this is in principle consistent with the concept of command releasing systems. (v) There is evidence for reciprocal tectal/medullary excitatory pathways suitable for premotor warming-up. (vi) Cyclic bursting of many neurons, spontaneously or as a post-stimulus sustaining event, points to a medullary premotor/motor property. 相似文献
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W. W. Schwippert T. W. Beneke J. P. Ewert 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1990,167(4):509-520
Summary Intracellular recording and labeling of cells from the toad's (Bufo bufo spinosus) medulla oblongata in response to moving visual (and tactual) stimuli yield the following results. (i) Various response types characterized by extracellular recording in medullary neurons were also identified intracellularly and thus assigned to properties of medullary cell somata. (ii) Focussing on monocular small-field and cyclic bursting properties, somata of such neurons were recorded most frequently in the medial reticular formation and in the branchiomotor column but less often in the lateral reticular formation. (iii) Visual object disrimination established in pretectal/tectal networks is increased in its acuity in 4 types of medullary small-field neurons. The excitatory and inhibitory inputs to these neurons evoked by moving visual objects suggest special convergence likely to increase the filter properties. (iv) Releasing conditions, temporal pattern, and refractoriness of cyclic bursting neurons resemble membrane characteristics of vertebrate and invertebrate neurons known to play a role in premotor/motor activity. (v) Integrating functions of medullary cells have an anatomical correlate in the extensive arborizations of their dendritic trees; 5 morphological types of medullary neurons have been distinguished.Abbreviations A stripe moving in antiworm configuration - (W) moving in worm configuration - S square - BMC branchiomotor column - EPSP excitatory postsynaptic potential - IPSP inhibitory postsynaptic potential - RetF medullary reticular formation - RF receptive field - M neurons response properties of medullary neurons - T neurons classes of tectal neurons - TH neurons classes of thalamic/pretectal neurons - tr.tb.d. tractus tecto-bulbaris directus - tr.tbs.c. tractus tecto-bulbaris et spinalis cruciatus 相似文献
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Alexander V. Galazyuk Albert S. Feng 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1997,180(4):301-311
Responses of 117 single- or multi-units in the auditory cortex (AC) of bats (Myotis lucifugus) to tone bursts of different stimulus durations (1– 400 ms) were studied over a wide range of stimulus intensities to determine
how stimulus duration is represented in the AC. 36% of AC neurons responded more strongly to short stimulus durations showing
short-pass duration response functions, 31% responded equally to all pulse durations (i.e., all-pass), 18% responded preferentially
to stimuli having longer durations (i.e., long-pass), and 15% responded to a narrow range of stimulus durations (i.e., band-pass).
Neurons showing long-pass and short-pass duration response functions were narrowly distributed within two horizontal slabs
of the cortex, over the rostrocaudal extent of the AC. The effects of stimulus level on duration selectivity were evaluated
for 17 AC neurons. For 65% of these units, an increase in stimulus intensity resulted in a progressive decrease in the best
duration. In light of the unusual intensity-dependent duration responses of AC neurons, we hypothesized that the response
selectivities of AC neurons is different from that in the brainstem. This hypothesis was validated by results of study of
the duration response characteristics of single neurons in the inferior colliculus.
Accepted: 8 November 1996 相似文献
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Evoked potentials averaged with the help of an electronic computer (AEP) to brief sound stimuli of subthreshold (3–10 dB below the threshold of the signal's audibility), threshold, and superthreshold (10–60 dB above the threshold) intensity were recorded from the vertex and occipital region of the cranium in healthy people. The dynamics of the changes in the AEP with an increase in the intensity of the sound from subthreshold to superthreshold (60 dB) values was shown. The time and amplitude parameters of AEP to imperceptible and perceptible sound stimuli differed significantly. The most constant, and in many cases the only component of the AEP to an imperceptible stimulus was a long-latent, low-amplitude, slow positive oscillation. The participation of the cerebral cortex in the neural mechanisms of reactions to imperceptible sound stimuli is discussed.V. P. Serbskii Central Scientific-Research Institute of Forensic Psychiatry, Moscow. Translated from Neirofiziologiya, Vol. 3, No. 2, pp. 115–122, March–April, 1971. 相似文献
15.
Nelken I 《Current opinion in neurobiology》2004,14(4):474-480
Neuronal responses in auditory cortex show a fascinating mixture of characteristics that span the range from almost perfect copies of physical aspects of the stimuli to extremely complex context-dependent responses. Fast, highly stimulus-specific adaptation and slower plastic mechanisms work together to constantly adjust neuronal response properties to the statistics of the auditory scene. Evidence with converging implications suggests that the neuronal activity in primary auditory cortex represents sounds in terms of auditory objects rather than in terms of invariant acoustic features. 相似文献
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Andrej Čokl Klaus Kalmring Herbert Wittig 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1977,120(2):161-172
Summary Most of the auditory neurons in the ventral nerve cord ofLocusta migratoria carry information not only from the tympanal organs but also from the subgenual organs (vibration sensors). Six of the eight neuron types studied electrophysiologically respond to at least these two modalities. Artificial sounds (white noise and pure tones varying in frequency and intensity) and sinusoidal vibration (200 Hz with an acceleration of 15.8 cm/s2 or 2000 Hz and 87 cm/s2) were used as stimuli.Complex excitatory and/or inhibitory interactions of the signals from both tympanal organs form the discharge patterns of auditory ventral-cord neurons in response to stimulation with air-borne sound. Normally the input of the ipsilateral sense organ dominates. The response patterns of these same neurons elicited by vibration stimuli are formed differently, as follows: (1) the sensory inputs of all subgenual organs are integrated in the responses of the ventral-cord neurons; in a single neuron they have either excitatory or inhibitory effects, but not both. (2) The more legs vibrated, the larger is the response. (3) The subgenual organs in the middle legs are most effective, those in the hind legs least so. (4) Ipsilateral vibration has more effect than contralateral.The six auditory neurons react to vibration combined with air-borne sound in different ways. The B neuron is the only one inhibited by vibration stimuli. The G neuron has been studied more intensively; because its anatomical arrangement and the location of the endings of the subgenual receptor fibers are known, it could be inferred from effects of transection of the connectives that interneurons are interposed between receptor cells and the G neuron.Part of the program Sonderforschungsbereich 114 (Bionach) Bochum, under the auspices of the Deutsche Forschungsgemeinschaft, with the support of the Slovenic Research Society (RSS) 相似文献
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Jun-Ya Okamura Yoshihiro Toh 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2001,187(9):713-725
Intracellular responses of medulla neurons (second-order visual interneurons) have been examined in the tiger beetle larva. The larva possesses six stemmata on either side of the head, two of which are much larger than the remaining four. Beneath the cuticle housing the stemmata an optic neuropil complex occurs consisting of lamina and medulla neuropils. Response patterns of medulla neurons to illumination and moving objects varied from neurons to neurons. For movement stimuli black discs and a black bar were moved in the rostro-caudal direction above the larva. Comparison of responses to the discs and the bar suggested a spatial summation of responses in some neurons, and tuning to small objects in some neurons. The majority of neurons responded to objects moving at heights of 10 mm and 50 mm with the same discharge pattern. A few neurons, however, showed distance sensitivities responding with an increase of spike discharges to moving objects only at either of the two heights. Such distance sensitivities still remained in one-stemma larvae, three of the four stemmata being occluded. These data are discussed in relation to distinct visual behavior of the larva and with special reference to perception of the hunting range. 相似文献
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C. H. Keller T. T. Takahashi 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1996,178(4):499-512
The natural acoustical environment contains many reflective surfaces that give rise to echoes, complicating the task of sound localization and identification. The barn owl (Tyto alba), as a nocturnal predator, relies heavily on its auditory system for tracking and capturing prey in this highly echoic environment. The external nucleus of the owl's inferior colliculus (ICx) contains a retina-like map of space composed of space-specific auditory neurons that have spatially limited receptive fields. We recorded extracellularly from individual space-specific neurons in an attempt to understand the pattern of activity across the ICx in response to a brief direct sound and a simulated echo. Space-specific neurons responded strongly to the direct sound, but their response to a simulated echo was suppressed, typically, if the echo arrived within 5 ms or less of the direct sound. Thus we expect there to be little or no representation within the ICx of echoes arriving within such short delays.Behavioral tests using the owl's natural tendency to turn their head toward a sound source suggested that owls, like their space-specific neurons, similarly localize only the first of two brief sounds. Naive, untrained owls were presented with a pair of sounds in rapid succession from two horizontally-separated speakers. With interstimulus delays of less than 10 ms, the owl consistently turned its head toward the leading speaker. Longer delays elicited head turns to either speaker with approximately equal frequency and in some cases to both speakers sequentially.Abbreviations
IC
inferior colliculus
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ICx
external nucleus of the inferior colliculus
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ITD
interaural time difference
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ISI
interstimulus interval
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LS
left speaker
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RS
right speaker
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CS
centering speaker
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RF
receptive field 相似文献