Activity-Dependent Sensitivity of Proprioceptive Sensory Neurons in the Stick Insect Femoral Chordotonal Organ

2002 ◽  
Vol 88 (5) ◽  
pp. 2387-2398 ◽  
Author(s):  
Ralph A. DiCaprio ◽  
Harald Wolf ◽  
Ansgar Büschges
Keyword(s):  
Sensory Neurons ◽  
Mechanical Stimulation ◽  
Stick Insect ◽  
Chordotonal Organ ◽  
Afferent Neurons ◽  
Generator Potential ◽  
Slow Adaptation ◽  
Wide Range ◽  
Mechanical Factors ◽  
Stimulation Of

Mechanosensory neurons exhibit a wide range of dynamic changes in response, including rapid and slow adaptation. In addition to mechanical factors, electrical processes may also contribute to sensory adaptation. We have investigated adaptation of afferent neurons in the stick insect femoral chordotonal organ (fCO). The fCO contains sensory neurons that respond to position, velocity, and acceleration of the tibia. We describe the influence of random mechanical stimulation of the fCO on the response of fCO afferent neurons. The activity of individual sensory neurons was recorded intracellularly from their axons in the main leg nerve. Most fCO afferents (93%) exhibited a marked decrease in response to trapezoidal stimuli following sustained white noise stimulation (bandwidth = 60 Hz, amplitudes from ±5 to ±30°). Concurrent decreases in the synaptic drive to leg motoneurons and interneurons were also observed. Electrical stimulation of spike activity in individual fCO afferents in the absence of mechanical stimulation also led to a dramatic decrease in response in 15 of 19 afferents tested. This indicated that electrical processes are involved in the regulation of the generator potential or encoding of action potentials and partially responsible for the decreased response of the afferents. Replacing Ca2+ with Ba2+ in the saline surrounding the fCO greatly reduced or blocked the decrease in response elicited by electrically induced activity or mechanical stimulation when compared with control responses. Our results indicate that activity of fCO sensory neurons strongly affects their sensitivity, most likely via Ca2+-dependent processes.

Connections between thoraco-coxal proprioceptive afferents and motor neurons in the locust

2000 ◽  
Vol 203 (3) ◽  
pp. 435-445
Author(s):  
M. Wildman
Keyword(s):  
Electrical Stimulation ◽  
Sensory Neurons ◽  
Motor Neurons ◽  
Chordotonal Organ ◽  
Synaptic Connections ◽  
Afferent Neurons ◽  
Postsynaptic Potentials ◽  
The Common ◽  
Proprioceptive Afferents ◽  
Stimulation Of

The position of the coxal segment of the locust hind leg relative to the thorax is monitored by a variety of proprioceptors, including three chordotonal organs and a myochordotonal organ. The sensory neurons of two of these proprioceptors, the posterior joint chordotonal organ (pjCO) and the myochordotonal organ (MCO), have axons in the purely sensory metathoracic nerve 2C (N2C). The connections made by these afferents with metathoracic motor neurons innervating thoraco-coxal and wing muscles were investigated by electrical stimulation of N2C and by matching postsynaptic potentials in motor neurons with afferent spikes in N2C. Stretch applied to the anterior rotator muscle of the coxa (M121), with which the MCO is associated, evoked sensory spikes in N2C. Some of the MCO afferent neurons make direct excitatory chemical synaptic connections with motor neurons innervating the thoraco-coxal muscles M121, M126 and M125. Parallel polysynaptic pathways via unidentified interneurons also exist between MCO afferents and these motor neurons. Connections with the common inhibitor 1 neuron and motor neurons innervating the thoraco-coxal muscles M123/4 and wing muscles M113 and M127 are polysynaptic. Afferents of the pjCO also make polysynaptic connections with motor neurons innervating thoraco-coxal and wing muscles, but no evidence for monosynaptic pathways was found.

Mechanical factors influencing response of joint afferent neurons from cat knee

1975 ◽  
Vol 38 (6) ◽  
pp. 1473-1484 ◽  
Author(s):  
P. Grigg
Keyword(s):  
Mechanical Stimulation ◽  
Angular Displacement ◽  
Afferent Neurons ◽  
Factors Influencing ◽  
Mechanical Factors ◽  
Stimulation Of

The responses of 67 slowly adapting joint afferent neurons in cat posterior articular nerve (PAN) were studied in relation to mechanical stimulation of the knee. The response of most neurons could be interpreted in terms of the stretching of joint tissues resulting from angular displacement of the knee. No neurons discharged at angles intermediate between the limits of movement of the joint. The limits of movement of the joint were operationally defined in terms of displacements resulting from applied torques.

Load Signals Assist the Generation of Movement-Dependent Reflex Reversal in the Femur–Tibia Joint of Stick Insects

2006 ◽  
Vol 96 (6) ◽  
pp. 3532-3537 ◽  
Author(s):  
Turgay Akay ◽  
Ansgar Büschges
Keyword(s):  
Time Course ◽  
Stick Insect ◽  
Motor Output ◽  
Chordotonal Organ ◽  
Frequency Of Occurrence ◽  
Stick Insects ◽  
Extensor Motoneuron ◽  
Motoneuron Activity ◽  
First Time ◽  
Stimulation Of

Reinforcement of movement is an important mechanism by which sensory feedback contributes to motor control for walking. We investigate how sensory signals from movement and load sensors interact in controlling the motor output of the stick insect femur–tibia (FT) joint. In stick insects, flexion signals from the femoral chordotonal organ (fCO) at the FT joint and load signals from the femoral campaniform sensilla (fCS) are known to individually reinforce stance-phase motor output of the FT joint by promoting flexor and inhibiting extensor motoneuron activity. We quantitatively compared the time course of inactivation in extensor tibiae motoneurons in response to selective stimulation of fCS and fCO. Stimulation of either sensor generates extensor activity in a qualitatively similar manner but with a significantly different time course and frequency of occurrence. Inactivation of extensor motoneurons arising from fCS stimulation was more reliable but more than threefold slower compared with the extensor inactivation in response to flexion signals from the fCO. In contrast, simultaneous stimulation of both sense organs produced inactivation in motoneurons with a time course typical for fCO stimulation alone, but with a frequency of occurrence characteristic for fCS stimulation. This increase in probability of occurrence was also accompanied by a delayed reactivation of the extensor motoneurons. Our results indicate for the first time that load signals from the leg affect the processing of movement-related feedback in controlling motor output.

scholarly journals II. Post-Tetanic Potentiation and Depression of Generator Potential in a Single Non-Myelinated Nerve Ending

1959 ◽  
Vol 43 (2) ◽  
pp. 347-376 ◽  
Author(s):  
Werner R. Loewenstein ◽  
Stanley Cohen
Keyword(s):  
Mechanical Stimulation ◽  
Sense Organ ◽  
Critical Parameters ◽  
Resting Membrane Potential ◽  
Ranvier Node ◽  
Generator Potential ◽  
After Effects ◽  
Receptor Membrane ◽  
Post Tetanic Potentiation ◽  
Stimulation Of

Repetitive activity at the non-myelinated ending of Pacinian corpuscles leaves the following after-effects: (1) With certain parameters of repetitive mechanical stimulation of the ending a depression in generator potential is produced. The effect is fully reversible and has low energy requirements. The effect is a transient decrease in responsiveness of the receptor membrane which is unrelated to changes in resting membrane potential. It appears to reflect an inactivation process of the receptor membrane. Within certain limits, the depression increases as a function of strength, frequency, and train duration of repetitive stimuli. (2) With other, more critical parameters of repetitive stimulation a hyperpolarization of the ending and of the first intracorpuscular Ranvier node may be produced. This leads to respectively post-tetanic potentiation of generator potential and increase in nodal firing threshold. The balance of these after-effects determines the threshold for the production of nerve impulses by adequate (mechanical) stimulation of the sense organ. The after-effects of activity at the node can be elicited by dromic (mechanical) stimulation of the ending, as well as by antidromic (electric) stimulation of the axon; the after-effects at the ending can only be produced by dromic and not by antidromic stimulation.

II. Integration of afferent signaling from the viscera by the nodose ganglia

2003 ◽  
Vol 284 (1) ◽  
pp. G8-G14 ◽  
Author(s):  
Kirsteen N. Browning ◽  
David Mendelowitz
Keyword(s):  
Sensory Neurons ◽  
Tissue Injury ◽  
Large Body ◽  
Sensory Function ◽  
Afferent Neurons ◽  
Nodose Ganglia ◽  
Vagal Afferent ◽  
Afferent Signaling ◽  
Recent Demonstration ◽  
Stimulation Of

To understand vago-vagal reflexes, one must have an appreciation of the events surrounding the encoding, integration, and central transfer of peripheral sensations by vagal afferent neurons. A large body of work has shown that vagal afferent neurons have nonuniform properties and that distinct subpopulations of neurons exist within the nodose ganglia. These sensory neurons display a considerable degree of plasticity; electrophysiological, pharmacological, and neurochemical properties have all been shown to alter after peripheral tissue injury. The validity of claims of selective recordings from populations of neurons activated by peripheral stimuli may be diminished, however, by the recent demonstration that stimulation of a subpopulation of nodose neurons can enhance the activity of unstimulated neuronal neighbors. To better understand the neurophysiological processes occurring after vagal afferent stimulation, it is essential that the electrophysiological, pharmacological, and neurochemical properties of nodose neurons are correlated with their sensory function or, at the very least, with their specific innervation target.

Contributions of structure and innervation pattern of the stick insect extensor tibiae muscle to the filter characteristics of the muscle-joint system

1996 ◽  
Vol 199 (10) ◽  
pp. 2185-2198 ◽  
Author(s):  
U Bässler ◽  
W Stein
Keyword(s):  
Distal Portion ◽  
Stick Insect ◽  
Extensor Muscle ◽  
Chordotonal Organ ◽  
Movement Amplitude ◽  
Joint System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Flexor Muscles ◽  
Stimulation Of

It is shown that the low-pass filter characteristics of the muscle­joint system of the femur­tibia joint of the stick insect Cuniculina impigra result from co-contraction of the extensor and flexor tibiae muscles. The most distal region of the extensor muscle, which contains a high percentage of slow muscle fibres, is involved in this co-contraction. This conclusion results from the following evidence. (1) Inertial and friction forces do not affect the characteristics of the low-pass filter of the muscle­joint system. (2) There is some co-contraction of the extensor and flexor muscles during sinusoidal stimulation of the femoral chordotonal organ at high stimulus frequencies. Both muscles generate tonic forces that increase with increasing stimulus frequency and also increase with time from the beginning of stimulation until a plateau is reached. (3) For the extensor muscle, this tonic force is produced by its most distal portion only. (4) Electrical stimulation of the common inhibitory motoneurone (CI1) reduces the tonic force generated in this most distal portion of the extensor muscle. Therefore, CI1 stimulation reduces the amplitude of tibial movement in response to sinusoidal stimulation of the femoral chordotonal organ at stimulus frequencies below 0.5 Hz (over this frequency range, the tibial movement amplitude is a function of the force amplitude produced by the whole extensor muscle and there is no co-contraction), but at chordotonal organ stimulus frequencies of 1 Hz and above, CI1 stimulation increases the tibial movement amplitude (in this case, movement amplitude is limited by the degree of co-contraction of the extensor and flexor muscles). With repeated chordotonal organ stimulation at higher stimulus frequencies, the tibial movement amplitude steadily decreases. This must be a consequence of increasing levels of co-contraction of the extensor and flexor muscles, since at low stimulus frequencies (no co-contraction) there is no reduction in movement amplitude during repeated stimulations. It is concluded that co-contraction of the extensor and flexor tibiae muscles prevents instability in the reflex loop in spite of the high gain necessary for the generation of catalepsy. Therefore, the mechanism described can be considered to be an adaptation to the ecological niche occupied by this animal. The contribution of the distal part of the extensor muscle to this system can be switched off by the CI1 during active movements.

Piezo-Electrically Driven Mechanical Stimulation of Sensory Neurons

2013 ◽  
pp. 159-170 ◽  
Author(s):  
Jizhe Hao ◽  
Jérôme Ruel ◽  
Bertrand Coste ◽  
Yann Roudaut ◽  
Marcel Crest ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Mechanical Stimulation ◽  
Stimulation Of

scholarly journals Motor Output of the Denervated Thoracic Ventral Nerve Cord in the Stick Insect Carausius Morosus

1983 ◽  
Vol 105 (1) ◽  
pp. 127-145 ◽  
Author(s):  
ULRICH BÄSSLER ◽  
U. T. A. WEGNER
Keyword(s):  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Intact Animal ◽  
Stick Insect ◽  
Motor Output ◽  
The Other ◽  
Chordotonal Organ ◽  
Motor Neurones ◽  
Leg Movements ◽  
Stimulation Of

The denervated thoracic ventral nerve cord produces a motor output which is similar to that observed in the intact animal during irregular leg movements (seeking movements) or rocking, but not walking. When the nerves to some legs are left intact, and the animal walks on a wheel, the motor output in the protractor and retractor motor neurones of the denervated legs is modulated by the stepping frequency of the walking legs. The modulation is similar to that observed in the motor output to a not actually stepping leg of an intact walking animal. When only the crural nerve of one leg is left intact, stimulation of the trochanteral campaniform sensilli induces protractor and retractor motor output to that leg and the leg behind it. In this case the motor output to the ipsilateral leg is in phase. Stimulation of the femoral chordotonal organ influences activity in motor neurones of the extensor tibiae (FETi and SETi) but not those of the protractor and retractor coxae muscles. In a restrained leg of an intact animal stretching of the femoral chordotonal organ excites FETi and SETi as long as the other legs walk (as in a walking leg) and inhibits FETi and SETi (as in a seeking leg) when the other legs are unable to walk.

scholarly journals Remote Control of the Swimmeret Central Pattern Generator in Crayfish (Procambarus Clarkii and Pacifastacus Leniusculus): Effect of a Walking Leg Proprioceptor

1992 ◽  
Vol 169 (1) ◽  
pp. 181-206 ◽  
Author(s):  
DANIEL CATTAERT ◽  
JEAN-YVES BARTHE ◽  
DOUGLAS M. NEIL ◽  
FRANCOIS CLARAC
Keyword(s):  
Electrical Stimulation ◽  
Mechanical Stimulation ◽  
Procambarus Clarkii ◽  
Beat Frequency ◽  
Rhythmic Activity ◽  
Chordotonal Organ ◽  
Disruptive Effect ◽  
Mechanical Stimuli ◽  
Electrical Stimuli ◽  
Stimulation Of

1. An isolated preparation of the crayfish nervous system, comprising both the thoracic and the abdominal ganglia together with their nerve roots, has been used to study the influence of a single leg proprioceptor, the coxo-basal chordotonal organ (CBCO), on the fictive swimmeret beating consistently expressed in this preparation. Both mechanical stimulation of the CBCO and electrical stimulation of its nerve were used. 2. In preparations not displaying rhythmic activity, electrical or mechanical stimulations evoked excitatory postsynaptic potentials (EPSPs) in about 30 % of the studied motor neurones with a fairly short and regular delay, suggesting an oligosynaptic pathway. Such stimulation could evoke rhythmic activity in swimmeret motor nerves. The evoked swimmeret rhythm often continued for several seconds after the stimulus period. 3. When the swimmeret rhythm was well established, electrical and mechanical stimuli modified it in a number of ways. Limited mechanical or weak electrical stimuli produced a small increase in swimmeret beat frequency, while more extreme movements of the CBCO or strong electrical stimuli had a disruptive effect on the rhythm. 4. The effect of low-intensity stimulation on existing swimmeret beating was phase-dependent: it shortened the beat cycle when applied during the powerstroke phase and lengthened it when applied during the retumstroke phase. 5. Rhythmic mechanical stimulation of CBCO or electrical stimulation of the CBCO nerve entrained the swimmeret rhythm within a limited range in relative or absolute coordination. Note: To whom reprint requests should be sent.

Sign in / Sign up

Export Citation Format

Share Document