Interactions Between Neurones Mediating Tuft Withdrawal in Tritonia Hombergi

1974 ◽  
Vol 61 (3) ◽  
pp. 655-666
Author(s):  
D. A. DORSETT ◽  
A. O. D. WILLOWS
Keyword(s):  
Motor Activity ◽  
Stimulus Intensity ◽  
Large Amplitude ◽  
Sensory Input ◽  
Behavioural Response ◽  
Spike Pattern ◽  
General Increase ◽  
Repeated Use ◽  
Three Stages ◽  
Central Excitability

The seven neurones that command the three stages of branchial tuft withdrawal interact by electrotonic and chemically mediated polysynaptic pathways. The pleural tuft retractors, L and R Pl 6, make electrotonic synapses with the ipsilateral neuronesPd2, which cause retraction of the tips of the tufts. The chemically transmitting pathways, between these and other retractor neurones, are mostly reciprocal and can be classified as weak or strong. The former are small in amplitude, with long latencies (1-3 sec) and are labile to repeated activation; the latter are of large amplitude and shorter latency (0·5-0·8 sec), but may still show decrement with repeated use. Frequently the p.s.p. shows indications of 1:1 correlation with the spike pattern in the driven neurone, but the long latencies require the presence of at least one interneurone in the pathway. The progressive spread of the behavioural response (withdrawal of the tips, complete unilateral withdrawal, complete bilateral withdrawal of all tufts), which occurs with increasing stimulus intensity, is not dependent on a central hierarchy in the activation of the tuft retractor neurones. Reciprocal feedback leads to a general increase in central excitability, the threshold for more extensive responses being probably determined largely by the sensory input to individual neurones. The unique pleural cell R Pl 5 is exceptional, both in the variety of motor activity it commands and in the absence of reciprocal connexions from other retractor neurones.

Movements and Motor Patterns of the Buccal Mass of Pleurobranchaea During Feeding, Regurgitation and Rejection

1982 ◽  
Vol 98 (1) ◽  
pp. 195-211
Author(s):  
ANDREW D. McCLELLAN
Keyword(s):  
Motor Activity ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Behavioural Response ◽  
Rhythmic Movements ◽  
Motor Patterns ◽  
Jaw Muscles ◽  
Behavioural Responses ◽  
Buccal Mass ◽  
Different Types

Feeding, regurgitation, and rejection in the marine gastropod Pleurobranchaea all involve similar but not identical rhythmic movements of buccal mass structures such as the radula, jaws and lips. The part of the motor pattern which produces rhythmic radula movement, as recorded in the major external muscles of the buccal mass of behaving semi-intact preparations, was similar during the three different types of behaviour, suggesting that they share a common motor-pattern generator. Other parts of the motor pattern were only obviously different during the vomiting phase of regurgitation. Differences in the function and motor patterns of feeding and rejection are presumably accounted for by differences in the activity of muscles which could not be recorded from in this study (e.g. jaw muscles). A general conclusion is that buccal rhythms in gastropods cannot automatically be assumed to underlie feeding, and this is particularly true for dissected preparations which do not execute a clear behavioural response. It would be necessary either to record motor activity that is unique for a given behaviour, or to employ preparations which execute unambiguous behavioural responses.

Primitive nervous systems: electrophysiology of the pharynx of the polyclad flatworm, Enchiridium punctatum

1976 ◽  
Vol 65 (3) ◽  
pp. 627-642
Author(s):  
G. Stone ◽  
H. Koopowitz
Keyword(s):  
Motor Activity ◽  
Electrical Activity ◽  
Behavioural Response ◽  
Nervous Systems ◽  
Stimulus Parameters ◽  
Conduction Velocities ◽  
Primitive Nervous Systems ◽  
Behavioural Sequence ◽  
Aperture Closure ◽  
Muscle Potential

1. Electrical activity accompanying motor activity can be recorded from the excised pharynx of Enchiridium punctatum. Multiple stimuli elicit behaviour which consists of an initial aperture closure followed by extension and then peristalsis. If the stimulus parameters are increased the preparation bends from side to side instead of proceeding through the behavioural sequence. Bending appears to inhibit other movements differentially. 2. The conduction involved with peristalsis is polarized and proceeds in a proximal direction. 3. With stimulus intensities greater than those needed to produce the behavioural response an initial muscle potential (IMP) is evoked. The IMP is frequency sensitive. Maximum facilitation occurs within 100 ms and drops to 50% of maximum within 250 ms. 4. Conduction velocities of the IMP range from 0–05 m s-1 to 1-9 m s-1. Conduction velocities appear to increase with facilitation.

scholarly journals Behavioural Responses of Stallions to a Novel Object

2016 ◽  
Vol 73 (2) ◽  
pp. 443
Author(s):  
Silvana Popescu ◽  
Eva Diugan ◽  
Daniela Oros ◽  
Caius Stepan ◽  
Liana Danci ◽  
...  
Keyword(s):  
Behavioural Response ◽  
The Novel ◽  
Statistical Software ◽  
Novel Object ◽  
Behavioural Responses ◽  
Individual Housing ◽  
Three Stages

The aim of this study was to test the response towards a novel object in Lipizzaner and Romanian Draft stallions. In addition the effect of the object’s colour on the behavioural response of the horses was investigated. The novel object test was performed in Lipizzaner (n = 11) and Romanian Draft (n = 8) stallions, in four different stages, observing the stallions during 45 minutes in each stage (15 minute/colour ball), and assessing a series of behavioural indicators. The data were analyzed using the SPSS statistical software. There were no significant differences in the response of the horses to the novel object in the three stages, or between the different breeds. An important result was the absence of discrimination of colour differences; the stallions were behaving similarly, irrespective to the colour of the ball. Based on the obtained results it can be concluded that the stallions were receptive to the novel object, they liked the balls, and these can be used to alleviate the monotony in the periods of individual housing in boxes.

scholarly journals Neural excitability and sensory input determine intensity perception with opposing directions in initial cortical responses

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Tilman Stephani ◽  
Alice Hodapp ◽  
Mina Jamshidi Idaji ◽  
Arno Villringer ◽  
Vadim V Nikulin
Keyword(s):  
Stimulus Intensity ◽  
Sensory Input ◽  
Sensory Information ◽  
Single Trial ◽  
Brain Potentials ◽  
Neural Excitability ◽  
Intensity Perception ◽  
Cortical Responses ◽  
Common Framework ◽  
Stimulus Features

Perception of sensory information is determined by stimulus features (e.g., intensity) and instantaneous neural states (e.g., excitability). Commonly, it is assumed that both are reflected similarly in evoked brain potentials, that is, larger amplitudes are associated with a stronger percept of a stimulus. We tested this assumption in a somatosensory discrimination task in humans, simultaneously assessing (i) single-trial excitatory post-synaptic currents inferred from short-latency somatosensory evoked potentials (SEPs), (ii) pre-stimulus alpha oscillations (8–13 Hz), and (iii) peripheral nerve measures. Fluctuations of neural excitability shaped the perceived stimulus intensity already during the very first cortical response (at ~20 ms) yet demonstrating opposite neural signatures as compared to the effect of presented stimulus intensity. We reconcile this discrepancy via a common framework based on the modulation of electro-chemical membrane gradients linking neural states and responses, which calls for reconsidering conventional interpretations of brain potential magnitudes in stimulus intensity encoding.

Integration of nonphaselocked exteroceptive information in the control of rhythmic flight in the locust

1985 ◽  
Vol 53 (5) ◽  
pp. 1201-1218 ◽  
Author(s):  
H. Reichert ◽  
C. H. Rowell
Keyword(s):  
Motor Activity ◽  
Flight Control ◽  
Sensory Input ◽  
Sensory Information ◽  
Short Latency ◽  
Synaptic Potentials ◽  
Direct Pathway ◽  
Descending Neurons ◽  
Flight Motor ◽  
Synaptic Effects

The integration of exteroceptive information in the flight control system of the locust was studied by determining the cellular basis of ocellar- (simple eye) mediated control of flight. Neural interactions that transform phase-independent sensory input into phase-specific motor output were characterized. Ocellar information about course deviations during flight was conveyed to the segmental thoracic ganglia by three pairs of large fast multimodal descending neurons. These made connections with thoracic motoneurons directly, via short-latency mono-or disynaptic pathways, and indirectly, via a population of intercalated thoracic interneurons. The synaptic potentials caused in the motoneurons by the direct pathway occurred at short latency and were adequate for summation with other types of sensory input. However, the strength of the synaptic effects of this pathway was weak compared with the central flight oscillator drive to the same motoneurons. In contrast, synaptic potentials evoked by the descending neurons in the thoracic interneurons were often large and brought these cells close to threshold. In turn, these interneurons always had stronger synaptic effects on postsynaptic flight motoneurons than did the descending neurons alone. We conclude that the indirect interneuronal pathway is more powerful in its effects on motoneurons than the direct pathway. Premotor thoracic interneurons, which received ocellar input appropriate for a role in correctional steering, were also rhythmically modulated during flight motor activity in phase with either depressor or elevator motoneurons. This phasic modulatory drive occurred in deafferented preparations, indicating that its source is the central oscillator for flight. Presentation of ocellar stimulation during flight motor activity showed that the central oscillatory modulation of the thoracic interneurons gated the transmission of sensory information through these interneurons. Ocellar-mediated postsynaptic potentials influenced the firing of thoracic interneurons only if they arrived during the proper phase of rhythmic drive. Thus the transmission of ocellar information from interneuron to motor neuron is possible only during appropriate phases of the flight cycle.

Temporal Experience as a Function of Sensory Stimulation and Motor Activity

1967 ◽  
Vol 25 (3) ◽  
pp. 997-1000 ◽  
Author(s):  
Alan R. Miller ◽  
Roland A. Frauchiger ◽  
Vernon L. Kiker
Keyword(s):  
Motor Activity ◽  
Linear Relationship ◽  
Sensory Input ◽  
Motor Behavior ◽  
Sensory Stimulation ◽  
Temporal Experience ◽  
Information Input ◽  
Temporal Judgments

This study was concerned with establishing quantifiable continua of phenomenal temporal judgments. Using 6 levels of sensory input and 3 levels of motor behavior, a linear relationship was found between sensory input and temporal estimations for a 90-sec. interval. Both sensory input and motor behavior had significant effects, but not the interaction. It was postulated that the so-called unfilled interval could be better understood if it could be related to various levels of information input.

scholarly journals Motor activity during searching and walking movements of cockroach legs

1987 ◽  
Vol 133 (1) ◽  
pp. 111-120 ◽  
Author(s):  
F. Delcomyn
Keyword(s):  
Motor Activity ◽  
Sensory Input ◽  
Motor Pattern ◽  
Simple Analysis ◽  
Rhythmic Motor ◽  
Different Types ◽  
Burst Pattern ◽  
Leg Muscle ◽  
Leg Movements

1. Rhythmic motor activity may be recorded in the legs of cockroaches during the execution of several different types of behaviour that involve leg movements. It was examined in detail during searching and walking. 2. During walking, motor activity always consisted of a series of bursts separated by silent periods. During searching, it was usually continual, but modulated in frequency. 3. Sometimes, the motor pattern recorded from a searching leg was burst-like rather than modulated. In these cases, it could nevertheless be reliably distinguished from the motor pattern recorded during walking by a simple analysis of the burst pattern. 4. An analysis of the motor pattern recorded during righting indicated that this pattern was more like that for walking than that for searching. Therefore, searching is not simply walking that lacks certain periodic sensory input due to leg contact with the ground. 5. It is concluded that walking and searching can be reliably distinguished from one another on the basis of an analysis of a record of motor activity in a single leg muscle only. An ability to distinguish between similar types of behaviour on the basis of the motor pattern may prove useful in a variety of experiments.

Function of sensory input in Insect motor systems

1981 ◽  
Vol 59 (7) ◽  
pp. 660-666 ◽  
Author(s):  
K. G. Pearson
Keyword(s):  
Motor Activity ◽  
Motor System ◽  
Sensory Input ◽  
External Environment ◽  
Motor Systems ◽  
Environmental Disturbances ◽  
Reflex Pathways ◽  
Locust Flight ◽  
And Function

The organization and function of sensory input has been examined in three insect motor systems: locust jumping, cockroach walking, and locust flight. In these three systems sensory input is primarily involved in the production of the normal patterns of motor activity rather than in the compensation for sudden changes in the external environment. At least two general functions for sensory input in the normal patterning of motor activity can be identified: (1) compensation for changes in the peripheral elements of the motor system which occur as a result of use and maturation and (2) regulation of switching from one phase of a movement to another following the attainment of a specific state by peripheral structures. Reflex pathways may exist for compensating for sudden environmental disturbances but these have not yet been clearly demonstrated.

Motor Control of Aimed Limb Movements in an Insect

2008 ◽  
Vol 99 (2) ◽  
pp. 484-499 ◽  
Author(s):  
Keri L. Page ◽  
Jure Zakotnik ◽  
Volker Dürr ◽  
Thomas Matheson
Keyword(s):  
Motor Activity ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Large Amplitude ◽  
The Body ◽  
Movement Direction ◽  
Joint Movement ◽  
Skeletal System ◽  
Limb Movements ◽  
Co Activation

Limb movements that are aimed toward tactile stimuli of the body provide a powerful paradigm with which to study the transformation of motor activity into context-dependent action. We relate the activity of excitatory motor neurons of the locust femoro-tibial joint to the consequent kinematics of hind leg movements made during aimed scratching. There is posture-dependence of motor neuron activity, which is stronger in large amplitude (putative fast) than in small (putative slow and intermediate) motor neurons. We relate this posture dependency to biomechanical aspects of the musculo-skeletal system and explain the occurrence of passive tibial movements that occur in the absence of agonistic motor activity. There is little recorded co-activation of antagonistic tibial extensor and flexor motor neurons, and there is differential recruitment of proximal and distal flexor motor neurons. Large-amplitude motor neurons are often recruited soon after a switch in joint movement direction. Motor bursts containing large-amplitude spikes exhibit high spike rates of small-amplitude motor neurons. The fast extensor tibiae neuron, when recruited, exhibits a pattern of activity quite different to that seen during kicking, jumping, or righting: there is no co-activation of flexor motor neurons and no full tibial flexion. Changes in femoro-tibial joint angle and angular velocity are most strongly dependent on variations in the number of motor neuron spikes and the duration of motor bursts rather than on firing frequency. Our data demonstrate how aimed scratching movements result from interactions between biomechanical features of the musculo-skeletal system and patterns of motor neuron recruitment.

Perturbation of the motor system in freely walking cockroaches. I. Rear leg amputation and the timing of motor activity in leg muscles

1991 ◽  
Vol 156 (1) ◽  
pp. 483-502 ◽  
Author(s):  
F. Delcomyn
Keyword(s):  
Motor Activity ◽  
Sensory Input ◽  
Periplaneta Americana ◽  
Motor Pattern ◽  
The Body ◽  
Leg Muscles ◽  
Slow Walking ◽  
The Mean ◽  
Independent Effects ◽  
Leg Amputation

1. The effects of amputation of a rear leg on the pattern of motor activity in the legs of freely walking cockroaches (Periplaneta americana L.) were studied. 2. Amputation affected both the frequency and the timing (phase) of motor bursts during a stepping cycle. Bursts in the stump of an amputated rear leg and in the contralateral (intact) rear leg often occurred at two or three times the frequency of bursts in the other legs. The remaining legs also showed multiple bursting during some steps. 3. Amputation affected the phase of motor bursts in two different ways. First, for every leg pair, phase was more variable after amputation, whether or not the mean phase was affected. Second, for some leg pairs, the mean phase itself was altered. During most steps, the timing of motor bursts in the stump of the amputated leg was walking-speed-dependent relative to bursts in the anterior legs. In contrast, the timing of bursts in the stump relative to bursts in the legs across the body from it showed no such speed-dependent timing. Timing between bursts in pairs of intact legs also showed either speed-dependent or speed-independent effects, depending on the pair under consideration. 4. The effects of amputation were not consistent. After loss of a leg, bursts in some leg pairs occurred synchronously in some insects and alternately in others. Even in single insects there were cases in which the timing between bursts in two legs switched from one value to another during walking. 5. These effects of amputation were manifest during slow walking only. At higher speeds, the timing of motor bursts in different pairs of legs was consistently closer to that seen during walking in intact insects. 6. Three conclusions are drawn from these results. (i) During slow walking, sensory feedback from the legs helps maintain the timing of adjacent ipsilateral leg pairs, but has little influence on contralateral pairs. (ii) During slow walking, either sensory input is quite variable, or it has variable effects on the motor pattern. (iii) During fast walking, sensory input from the legs seems to play a minimal role, if any, in the timing of the motor pattern of walking.

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