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  • 1
    Electronic Resource
    Electronic Resource
    Response entrainment of movement fibers in the optic tract of crayfish (1975)
    Springer
    Biological cybernetics 20 (1975), S. 213-222 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract The response properties of jittery movement fibers (JMF) in the crayfish optic tract reacting to a non-moving temporally patterned light were analyzed. The JMFs usually show no response during the regular flickering of stationary light with a flash duration of less than 50 msec when the stimulus frequency is between 4 and 20 per second; however they do respond when the flickering stops if a certain number of flashes have been given. The response appears about 50 msec after the first missing flash, i.e., the latency of the response after the last flash of the train changed from 100 to 300 msec. Thus, the “off” response at the end of the flicker is entrained to the stimulus repetition interval and locked onto the time of the first missing flash. The response of a sustaining fiber to an identical stimulus has quite different features as illustrated in Fig. 2. Some of the fibers show responses to the beginning part of the flicker but not necessarily to each flash, and habituate after several flashes. When a single flash longer than 250 msec is given, the fiber shows an “off” response with about 50 msec latency, as it does to sustained light. Some fibers show a double burst of “off” discharge to single flashes; the first at 50 msec is followed after 120 msec by the second one. However, when the flash duration is between 250 and 50 msec, a single flash elicits little or no response. The latency of the “off” response is as much as 300 msec for short single flashes less than 50 msec. An “on” response to flashes of light is observed when the inter-stimulus interval is more than 5 sec. The responses to the beginning part of flicker train are not simply locked to the just preceding flash except the “on” response to the very first one, but they can be the long latency responses to the flash before that. This response is modified in latency by the succeeding flashes in flicker trains and becomes entrained to the missing flash. Four types of entrainment are classified on the basis of the change in latency from the missing flash with regard to the number of flashes in a train. In most cases, 10 flashes are sufficient to entrain the response to the first missing flash. Non-resposiveness, i.e., habituation, during a regular flicker, may be due to an active inhibitory process, initiated by each succeeding light pulse. The response to the missing flash, therefore results from a disinhibited modified response to the last flash. Some JMFs continue to respond to the flicker even after a considerable number of flashes but only when the repetition interval is about 120 msec corresponding well to the interval of the double burst “off” discharge, thus the JMF has a resonant frequency of about 8 Hz. The JMFs appear to be acting as an irregularity detector in temporal sequence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00342641
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  • 2
    Electronic Resource
    Electronic Resource
    Analysis of neural spike trains with interspike interval reconstruction (2000)
    Springer
    Biological cybernetics 82 (2000), S. 305-311 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract. As a method for the analysis of neural spike trains, we examine fundamental characteristics of interspike interval (ISI) reconstruction theoretically with a leaky-integrator neuron model and experimentally with cricket wind receptor cells. Both the input to the leaky integrator and the stimulus to the wind receptor cells are the time series generated from the Rössler system. By numerical analysis of the leaky integrator, it is shown that, even if ISI reconstruction is possible, sometimes the entire structure of the Rössler attractor may not be reconstructed with ISI reconstruction. For analysis of the in vivo physiological responses of cricket wind receptor cells, we apply ISI reconstruction, nonlinear prediction and the surrogate data method to the experimental data. As a result of the analysis, it is found that there is a significant deterministic structure in the spike trains. By this analysis of physiological data, it is also shown that, even if ISI reconstruction is possible, the entire attractor may not be reconstructed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004220050584
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  • 3
    Electronic Resource
    Electronic Resource
    A threshold analysis of cricket cercal interneurons by an alternating air-current stimulus (1984)
    Springer
    Journal of comparative physiology 154 (1984), S. 357-365 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The wind-velocity threshold of cercal interneurons of the cricketGryllus bimaculatus D. was measured using a sinusoidally alternating aircurrent stimulus. Two stimulus parameters, peak velocity and alternating frequency of the air current, were separately controlled. The measurements of the minimum velocity evoking a response at a variety of frequencies gave a threshold curve. The stimulating apparatus was a wind tunnel which consisted of a pair of push-pull driven loudspeakers. The peak velocity was controlled within the range of 300 mm/s-0.01 mm/s (90 dB) and the frequency between 2 Hz and 100 Hz. 2. The interneurons were classified in three types: P- (phasic), T- (tonic), PT- (phasic-tonic) in accordance with their adaptation rate to a ‘burst stimulus’ of alternating air current (Fig. 3). The threshold curve of each type of interneuron showed distinctive dependency on the frequency. Seven cercal interneurons were characterized by their differing threshold curves, and six of them were morphologically identified using Lucifer Yellow marking after intracellular recording. 3. The velocity threshold of the two P-type interneurons decreased by about 20 dB for a decade increase of alternating frequency; it seems, therefore, that they work as acceleration detectors. Their thresholds were about 0.06 m/s2 and 1.1m/ s2, respectively. The one with the lower threshold was identified as 9-1 (LGI: the lateral giant interneuron) (Fig. 4). 4. T-type interneurons showed high sensitivity to a lower frequency of air current. Their threshold curves were almost flat (Fig. 5). They are velocity dependent and their threshold values are about 30 μm/s at 5 Hz. The two T-type interneurons respond to the in- and anti-phases of the alternating air current (Fig. 6 A); their preferred directions are opposite to each other. They were morphologically identified as the sensory interneurons 10-2 and 10-3. 5. Three PT-type interneurons 8-1 (MGI: medial giant interneuron), 9-2 and 9-3 were also identified. MGI had threshold curves with slopes of 30 dB per decade change of frequency (dB/dec) while the other two had 20 dB/dec slopes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00605235
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  • 4
    Electronic Resource
    Electronic Resource
    Varieties of filiform hairs: range fractionation by sensory afferents and cereal interneurons of a cricket (1984)
    Springer
    Journal of comparative physiology 155 (1984), S. 485-493 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Wide variations in the size of the cercal filiform hairs inGryllus bimaculatus are described (Figs. 1, 2). The length of the hairs varies from 30 to 1,500 μm, while the diameter varies from 1.5 to 9 μm (Fig. 2). The range of hair length overlaps well with the physical depth of air-motion on a substrate floor. The length dependency of sensory threshold to air-current stimulus is predictable. 2. The sensory threshold to the alternating air-current stimulus was measured. The sensory afferent was penetrated at the cereal nerve bundle. The length of the filiform hair of the recorded afferent was identified by needle probe. All sensory afferents showed phase locked responses to each cycle of bursts of sinusoidal air-current (Fig. 3). 3. The long filiform hairs are spontaneously active and sensitive to a low frequency stimulus (Figs. 3, 4). They are regarded as velocity sensitive hairs. The short hairs are spontaneously inactive and insensitive to low frequency stimulus. They are acceleration sensitive hairs. 4. The selective deprivation of the sensory hairs longer than 500 μm has little effect on the threshold of large interneurons 9-1 (LGI) and 8-1 (MGI) (Fig. 6). Under the same deprivation we were unable to record small-sized interneurons 10-2 and 10-3. 5. The threshold curves of the sensory hairs and those of the cereal interneurons are compared (Fig. 7). The conspicuously long cereal filiform hairs converge upon two small sized interneurons 10-2 and 10-3. Large cereal interneurons 9-1 (LGI) and 8-1 (MGI) receive the main excitatory sensory input from the short hairs around 200–300 μm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00611913
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  • 5
    Electronic Resource
    Electronic Resource
    The aerodynamics and sensory physiology of range fractionation in the cereal filiform sensilla of the cricketGryllus bimaculatus (1984)
    Springer
    Journal of comparative physiology 155 (1984), S. 495-505 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The deflection amplitude of cereal filiform hairs of different lengths was determined for various frequencies of air-current (Fig. 4). The angle threshold of the sensory neuron was then determined (Fig. 7). Both the deflection amplitude and angle threshold were length dependent. 2. In order to estimate the hair deflection, the spring stiffness of the hair supporting apparatus was measured. The stiffness varies by 102 depending on the hair length (Fig. 1). 3. Based on the mechanical properties measured, the deflection amplitude of hair in the sinusoidal air-current is estimated by means of a numerical solution of the equation of motion. The effect of the boundary layer due to the viscosity of air was taken into account. Long filiform hairs deflect more sensitively than short ones in the frequency range below 100 Hz (Fig. 4). 4. We compared a theoretical estimation of hair deflection with direct observation under relatively strong stimuli. The estimation and the observation are in good agreement (Fig. 5). 5. By using the estimated value of hair deflection and the sensory threshold (Shimozawa and Kanou 1984), we were able to determine the angle threshold of the sensory neuron. The angle threshold determined is 0.002° in long filiform hairs. In addition to this low angle threshold, sensory neurons with sensitivity only to fast deflection but not to slow deflection were revealed in association with the short filiform hairs (Fig. 7). 6. When oscillating, the filiform hairs show a self-damping property. The spring stiffness seems to be optimized in relation to the length and moment of inertia to give a critical-damping condition (Table 1). 7. The hair length, the spring stiffness, and the rate of relaxation of sensory neuron show a specific combination in a single sensillum. The specific combination underlies the range fractionation of the filiform sensilla.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00611914
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  • 6
    Electronic Resource
    Electronic Resource
    Neurohormonal control of the mating interval in the male cricket, Gryllus bimaculatus DeGeer (1991)
    Springer
    Journal of comparative physiology 168 (1991), S. 159-164 
    Details
    ISSN: 1432-1351
    Keywords: Neurohormone ; Mating interval ; Cricket ; Octopamine ; Serotonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Between two mating acts of the male cricket (Gryllus bimaculatus), spermatophore protrusion (SP) and courtship stridulation (CS), there is a fixed time interval. This interval lasts about 1 h. During the period from SP to CS, the male cricket does not stridulate nor make any type of mating sound (post-spermatophore protrusion silence: PSPS) and tolerates external sensory stimuli. We examined the effects of injections of hemolymph and ganglia extracts on the interval. Extracts obtained from crickets which had just started CS (CS crickets) and those which had finished SP (SP crickets) were effective. The extracts were fractionated by ul trafiltration. Fractions with a molecular weight of less than 1 kdalton affected the length of the PSPS. The fractions from both the hemolymph and the mesothoracic ganglion of CS crickets shortened the PSPS. On the other hand, the fractions from the hemolymph and the brain of SP crickets lengthened the PSPS. We estimated, by gel filtration, the molecular weight of the effective fractions from the mesothoracic ganglion and the brain to be 100–200 daltons. We also examined the effects of biogenic amines on the PSPS. Octopamine shortened the PSPS, whereas serotonin lengthened it. The results in dicate that at least two neurohormones from the brain and the mesothoracic ganglion reciprocally control the elicitation of CS and provide an appropriate interval in the mating sequence of the male cricket. Octopamine and serotonin are possible candidates for these neurohormones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218408
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  • 7
    Electronic Resource
    Electronic Resource
    Response entrainment and memory of temporal pattern by movement fibers in the crayfish visual system (1977)
    Springer
    Journal of comparative physiology 114 (1977), S. 267-287 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Most movement fibers in the crayfish optic nerve show no response during the regular flickering of a stationary light with a flash duration of less than 50 msec when the flash frequency is between 4 and 20 Hz (“habituation”), whereas they do respond with short “off” burst when the flickering stops after a certain number of flashes (“dishabituation”, Fig. 2). 2. The dishabituated response to cessation of regular flicker is not a normal “off” response because the discharge appears about 50 ms after the “missing flash” which would have occurred (Fig. 2). This fact indicates that the dishabituation to cessation of the flicker is entrained to the periodicity of the flicker and locked to the time of the first missing flash (Fig. 3). The features of this “entrained response” are not affected by differences in light intensity or flash duration of the flicker train used for entrainment (Fig. 4). 3. The timing of the entrained response can be shifted by a test flash following the entraining flicker. The entrained response advances when the test flash is given earlier than the expected flash, whereas it lags when the flash is given later. The amount of shift in the response timing is equal to the change in temporal position of the test flash (Fig. 5). The response also advances for a test flash of lower light value (light intensity × flash duration) than that of the entraining flicker, whereas it lags for a flash of higher light value. The amount of shift is proportional to the logarithm of the light value (Figs. 6, 7). 4. It is proposed that the habituation during regular flicker and dishabituation, that is, the entrained response evoked by cessation of the flicker, are both essentially based upon a copying mechanism of the incoming light pattern and a comparison mechanism between the copy and a newly incoming flash. These mechanisms are part of the circuitry of movement fibers (Fig. 11). The accuracy of the periodicity of the entrained activity is better than 5% of the original. 5. The movement fibers also show habituation and dishabituation to stimulus flicker with double periodicities consisting of paired flashes, so that the copying circuit can extract and store more than one periodicity at the same time (Figs. 9, 10).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00657323
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  • 8
    Electronic Resource
    Electronic Resource
    Auditory response properties and spatial response areas of superior collicular neurons of the FM bat,Eptesicus fuscus (1984)
    Springer
    Journal of comparative physiology 154 (1984), S. 407-413 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Electrophysiological properties of 279 single units in the superior colliculus (SC) of the big brown bat,Eptesicus fuscus, were studied by recording their responses to pure tone pulses and frequency-modulated stimuli. 2. The SC units generally fired only a few impulses to acoustic stimulus. They are not tonotopically organized along the dorsoventral axis of the SC (Fig. 1). 3. The response latency of 276 units was between 3.6 and 20 ms, but most (253 units) were below 12.5 ms (Fig. 2). 4. Tuning curves of 164 units are either narrow, intermediate, or broad, according to the bandwidth of the tuning curves (Fig. 3). Q10 dB values range between 1.21 (best frequency (BF) =33.52 kHz) and 68.9 (BF=69.94 kHz), but the majority are below 20. The minimum thresholds (MTs) of these units were between 15 and 104 dB SPL, but most were above 40 dB SPL. 5. MTs to pure tone pulses and one octave upward and downward sweeping FM stimuli were compared (Fig. 4). SC units generally had their lowest MTs to downward sweeping FM stimuli and their highest MTs to pure tone pulses (Table 1). 6. Intensity-rate functions of 16 SC units were measured with both pure tone pulses and upward and downward sweeping FM stimuli. There was no correlation between the type of intensity-rate function obtained and the type of acoustic stimulus used (Fig. 5). 7. Auditory spatial response areas were measured for 47 units. The size of the spatial response area increases with stimulus intensity (Fig. 6). The auditory space is not orderly represented in the SC of a bat (Fig. 7).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00605239
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  • 9
    Electronic Resource
    Electronic Resource
    Ecdysial growth of the filiform hairs and sensitivity of the cercal sensory system of the cricket,Gryllus bimaculatus (1988)
    Springer
    Journal of comparative physiology 162 (1988), S. 573-579 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The ecdysial growth of cercal filiform hairs was investigated in the cricketGryllus bimaculatus. The length of hairs varied from 40 to 500 μm in the 1st, from 40 to 650 μm in the 3rd and from 30 to 800 μm in the 5th instar nymphs (Fig. 1). Hemimetabolous development causes both hair growth and the appearance of new hairs at each ecdysis (Figs. 2, 3). The newly acquired hairs were shorter than 200 μm in every case (Fig. 4). 2. Velocity thresholds of cercal sensory interneurons (CSIs) to sinusoidal air-currents were measured in 3rd instar nymphs (Fig. 5 A, B, C). CSIs 8-1 (medial giant interneuron: MGI) and 9-1 (lateral giant interneuron: LGI) showed threshold curves of acceleration sensitivity similar to those in adults. The thresholds for CSIs 8-1 and 9-1 were on the average higher in nymphs than in adults. The threshold curves for the two velocity-sensitive CSIs 10-2 and 10-3 were similar for nymphs and adults. 3. Velocity thresholds of cercal filiform sensilla were measured in 3rd instar nymphs (Fig. 6). In spite of the small size of nymphal hairs, the most sensitive ones showed the same sensitivity as did the long 1000 μm hairs of the adult. 4. The filiform hairs in 3rd instar nymphs were supported by a weaker spring than in adults (Fig. 7). Relative stiffness was about 50% of that in the long hairs in adults, but not much different than that in the short hairs. 5. Based on a theoretical estimation of hair motion, the threshold angle of a filiform sensillum in the 3rd instar nymph was calculated (Fig. 9). Threshold angles of the long sensilla seemed to be unchanged throughout hemimetabolous development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01342632
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  • 10
    Electronic Resource
    Electronic Resource
    Erratum (1990)
    Springer
    Journal of comparative physiology 167 (1990), S. 200-200 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00188112
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