Behavior of cutaneous mechanoreceptors recorded in mandibular division of Gasserian ganglion of the rabbit during movements of lower jaw

1982 ◽  
Vol 47 (2) ◽  
pp. 151-166 ◽  
Author(s):  
K. Appenteng ◽  
J. P. Lund ◽  
J. J. Seguin
Keyword(s):  
Hair Follicle ◽  
Activity Patterns ◽  
Receptive Fields ◽  
Firing Frequency ◽  
Gasserian Ganglion ◽  
Afferent Activity ◽  
Cutaneous Mechanoreceptors ◽  
Lower Jaw ◽  
Movement Parameters ◽  
Anterior Posterior

1. The activity of cutaneous mechanoreceptors was recorded extracellularly in the mandibular division of the Gasserian ganglion of hemidecerebrate anesthetized rabbits. Fifty-four hair follicle afferents and 80 skin mechanoreceptor afferents were functionally identified. Their receptive-field characteristics were described and their activity patterns were recorded while the jaw was displaced by hand in the vertical, horizontal, and anterior-posterior directions, and during masticatory movements. 2. All hair follicle afferents were classified as rapidly adapting, whereas skin afferents could be divided into two categories: rapidly adapting and slowly adapting. Rapidly and slowly adapting receptors were found in all regions of the mandibular skin. Only one hair follicle afferent and four skin afferents fired spontaneously with the jaw at rest. 3. Fifty-eight percent (29/50) of the hair follicle afferents were activated by imposed displacement of the jaw and all of these tested also discharged during chewing. They were sensitive to movement in all three axes and their firing frequency was linearly related to the velocity, regardless of direction. 4. Only 10% (8/80) of the skin afferents were activated by imposed displacement of the jaw if their receptive fields were not directly contacted. Firing frequency was not well related to either the amplitude or velocity of movement. During chewing, the discharge frequency was variable but, in general, firing was restricted to the jaw-closing phase. Most skin afferents that were active during jaw movement had receptive fields close to the corner of the mouth. 5. The results are discussed within the context of a possible involvement of cutaneous afferents in kinesthesia and in the control of jaw movements. Hair afferents could make specific contributions to the appreciation of movement because their discharge pattern was clearly related to one of its parameters. The lack of activity of most skin afferents, as well as the absence of a strong correlation between the firing frequency of those that were active and the movement parameters, suggest that they do not make specific contributions to the awareness of movement. 6. Hair and skin afferents may also make different contributions to the control of ongoing movements. It is suggested that skin afferent activity during jaw closure may elicit a reflex reduction in the velocity or duration of this phase. Some evidence from other studies suggests that hair afferent activity may indirectly influence movement via effects on elevator fusimotor neurons.

Weather effects on intrahabitat movements of the western green lizard, Lacerta bilineata (Daudin, 1802), at its northern distribution range border: a radio-tracking study

2000 ◽  
Vol 78 (10) ◽  
pp. 1831-1839 ◽  
Author(s):  
P Sound ◽  
M Veith
Keyword(s):  
Activity Patterns ◽  
Strong Dependence ◽  
Weather Conditions ◽  
Distribution Range ◽  
Maximum Temperature ◽  
Second Phase ◽  
Northern Distribution ◽  
Radio Transmitters ◽  
Movement Parameters ◽  
Bad Weather

Daily activity patterns of male western green lizards, Lacerta bilineata (Daudin, 1802), at the edge of their northern distribution range in western Germany after the breeding season from June to October were recorded using implanted radio transmitters. Different activity indices discriminating between stimulation, duration, and length of movement were correlated with actual weather conditions (d0) and with weather conditions on the 2 previous days (d-1 and d-2). The lizards' dependence on weather showed two different phases throughout the study period. During the first period and in the period preceding a drastic change of weather in midsummer, weather had no significant influence on movement parameters. After that event, temperatures dropped and a strong dependence on weather of all movement parameters except those indicating displacements became apparent. Thresholds for 50% activity during this second phase were a maximum temperature of 17°C and a minimum humidity of 35%. Two days after periods of bad weather, the influence of weather conditions increased again. This can be explained by physiological deficits that require compensation during the period of marginal weather conditions prior to hibernation. Displacement movements were significantly longer than home-range movements and were neither triggered nor modulated by the weather. They must therefore represent activities such as patrolling territory boundaries.

The Exoskeleton and Insect Proprioception: III. Activity of Tribal Campaniform Sensilla During Walking in the American Cockroach, Periplaneta Americana

1981 ◽  
Vol 94 (1) ◽  
pp. 57-75
Author(s):  
SASHA N. ZILL ◽  
DAVID T. MORAN
Keyword(s):  
Stance Phase ◽  
Periplaneta Americana ◽  
Specific Activity ◽  
Firing Frequency ◽  
American Cockroach ◽  
Campaniform Sensilla ◽  
Afferent Activity ◽  
Step Cycle ◽  
Slow Walking ◽  
Oriented Parallel

1. In the cockroach tibia, the activities of campaniform sensilla that monitor cuticular strain have been recorded in free-walking animals. 2. In walking, sensillum firing is correlated with myographic activity of the flexor and extensor tibiae muscles. 3. The specific activity of a single campaniform sensillum depends upon the orientation of its cuticular cap. 4. In slow walking, proximal sensilla, whose ovoid cuticular caps are oriented perpendicular to the leg long axis, fire in bursts that are initiated just prior to the onset of extensor tibiae activity in the stance phase of locomotion. The firing frequency within bursts of proximal sensilla is generally inversely related to the frequency of the slow extensor tibiae motoneurone and ceases when motoneurone activity exceeds 200 Hz. 5. Distal campaniform sensilla, oriented parallel to the leg long axis, only fire when slow extensor tibiae activity exceeds 300 Hz. In slow walking, distal sensillum activity typically occurs as a short intense burst near the end of the stance phase of the step cycle, when slow extensor frequency is maximal. Distal sensillum firing is greatly increased when forward progression is impeded. 6. The patterns of afferent activity seen in slow walking indicate that the campaniform sensilla function in load compensation and limitation of muscle tensions. The proximal sensilla respond to initial loading of the leg and can reflexly excite the slow extensor motoneurone in compensation. The distal sensilla respond to cuticular strains that result from large extensor contractions and can reflexly inhibit the slow motoneurone. 7. In rapid walking, activities of both subgroups of campaniform sensilla shift in phase relative to slow extensor firing. Proximal sensilla activity occurs after the onset of slow extensor firing. Distal sensilla bursts follow the termination of slow extensor activity. 8. These phase shifts limit the reflex functions of the tibial campaniform sensilla in rapid walking. Shifts in phase of afferent activity may contribute to the need for central programming of locomotion.

Afferent-Induced Changes in Rhythmic Motor Programs in the Feeding Circuitry of Aplysia

2004 ◽  
Vol 92 (4) ◽  
pp. 2312-2322 ◽  
Author(s):  
Avniel N. Shetreat-Klein ◽  
Elizabeth C. Cropper
Keyword(s):  
Sensory Neurons ◽  
Motor Neurons ◽  
Rhythmic Activity ◽  
Motor Program ◽  
Firing Frequency ◽  
Afferent Activity ◽  
Motor Programs ◽  
Rhythmic Motor ◽  
Induced Changes ◽  
The Impact

A manipulation often used to determine whether a neuron plays a role in the generation of a motor program involves injecting current into the cell during rhythmic activity to determine whether activity is modified. We perform this type of manipulation to study the impact of afferent activity on feeding-like motor programs in Aplysia. We trigger biting-like programs and manipulate sensory neurons that have been implicated in producing the changes in activity that occur when food is ingested, i.e., when bites are converted to bite-swallows. Sensory neurons that are manipulated are the radula mechanoafferent B21 and the retraction proprioceptor B51. Data suggest that both cells are peripherally activated during radula closing/retraction when food is ingested. We found that phasic subthreshold depolarization of a single sensory neuron can significantly prolong radula closing/retraction, as determined by recording both from interneurons (e.g., B64), and motor neurons (e.g., B15 and B8). Additionally, afferent activity produces a delay in the onset of the subsequent radula opening/protraction, and increases the firing frequency of motor neurons. These are the changes in activity that are seen when food is ingested. These results add to the growing data that implicate B21 and B51 in bite to bite-swallow conversions and indicate that afferent activity is important during feeding in Aplysia.

Intraaxonal injection of neurobiotin reveals the long-ranging projections of A beta-hair follicle afferent fibers to the cat dorsal horn

1996 ◽  
Vol 76 (1) ◽  
pp. 242-254 ◽  
Author(s):  
P. Wilson ◽  
P. D. Kitchener ◽  
P. J. Snow
Keyword(s):  
Spinal Cord ◽  
Horseradish Peroxidase ◽  
Hair Follicle ◽  
Dorsal Horn ◽  
Receptive Fields ◽  
Dorsal Horn Neurons ◽  
Somatotopic Organization ◽  
Afferent Fibers ◽  
Synaptic Boutons

1. The morphology and somatotopic organization of the spinal arborizations of identified A beta-hair follicle afferent fibers (HFAs) with receptive fields (RFs) on the digits have been investigated in the cat by the use of intraaxonal injection of the tracer n-(2 aminoethyl) biotinamide. 2. In three cats, the long-ranging projections of six HFAs were examined by selectively injecting afferents with RFs on digit 2, 4, or 5, directly over the digit 3 representation, and examining their collateral morphology in transverse sections of the spinal cord. The rostral and caudal boundaries of the digit 3 representation were determined by mapping the RFs of identified spinocervical tract (SCT) neurons. 3. In two more cats, three HFAs were injected at random rostrocaudal positions and their morphology was examined in parasagittal sections. In one animal (2 HFAs), the somatotopy of the digit representation was again determined by mapping the RFs of SCT neurons. In the remaining cat (1 HFA), the somatotopy of the dorsal horn was mapped from the RFs of unidentified dorsal horn neurons. 4. Hair follicle afferents emitted many more collaterals, over much greater rostrocaudal distances, than indicated by previous horseradish peroxidase studies, and all collaterals gave rise to synaptic boutons. 5. HFAs that have RFs confined to a small part of a digit give rise to bouton-bearing axonal branches throughout the entire rostrocaudal extent of the hindpaw representation.

scholarly journals Activity Patterns of Interneurons in the Caudal Ganglion of the Crayfish

1960 ◽  
Vol 43 (3) ◽  
pp. 655-670 ◽  
Author(s):  
Donald Kennedy ◽  
James B. Preston
Keyword(s):  
Activity Patterns ◽  
Receptive Fields ◽  
Synaptic Activity ◽  
Constant Frequency ◽  
Natural Stimuli ◽  
Synaptic Potentials ◽  
Tactile Stimuli ◽  
Afferent Inputs ◽  
Degree Of Convergence ◽  
High Degree

Responses of ascending interneurons from the caudal ganglion of crayfish have been recorded from single units isolated by dissection from the ventral nerve cord; in addition, post-synaptic activity within the ganglionic neuropile has been studied with intracellular micropipettes. The following classes of interneurons have been found: (1) Large fibers which responded to tactile stimuli with single spikes or phasic bursts. These units usually showed broad receptive fields; and spontaneous activity, when present, showed transitory depressions following responses to natural stimuli. (2) A group of fibers, including many small ones, which responded to proprioceptive stimuli with tonic discharges of varying adaptation rate. (3) Interneurons which showed responses both to tactile stimuli and to activation of the sixth ganglion photoreceptor; and (4) units with constant frequency discharges which were unmodifiable by any of the above afferent inputs. Intracellular recording of post-synaptic activity has shown (1) that widely graded excitatory post-synaptic potentials occur; (2) that multiple firing from single synaptic potentials is usual; (3) that the post-synaptic responses to phasic natural stimuli and to electrical stimulation of ganglionic roots are similar. The existence of widely graded post-synaptic potentials and of extensive receptive fields suggests a high degree of convergence from primary afferents to interneurons. The activation of such post-synaptic units involves integrative synaptic transfer, without 1:1 correspondence between pre- and post-fiber activity.

scholarly journals The primary afferent activity cannot capture the dynamical features of muscle activity during reaching movements

2017 ◽  
Author(s):  
Russell L. Hardesty ◽  
Matthew T. Boots ◽  
Sergiy Yakovenko ◽  
Valeriya Gritsenko
Keyword(s):  
Muscle Activity ◽  
Sensory Feedback ◽  
Muscle Activation ◽  
Activity Patterns ◽  
Afferent Feedback ◽  
Reaching Movements ◽  
Afferent Activity ◽  
Primary Afferent ◽  
Limb Dynamics ◽  
Dynamical Features

AbstractThe stabilizing role of sensory feedback in relation to realistic 3-dimensional movement dynamics remains poorly understood. The objective of this study was to quantify how primary afferent activity contributes to shaping muscle activity patterns during reaching movements. To achieve this objective, we designed a virtual reality task that guided healthy human subjects through a set of planar reaching movements with controlled kinematic and dynamic conditions that minimized inter-subject variability. Next, we integrated human upper-limb models of musculoskeletal dynamics and proprioception to analyze motion and major muscle activation patterns during these tasks. We recorded electromyographic and motion-capture data and used the integrated model to simulate joint kinematics, joint torques due to muscle contractions, muscle length changes, and simulated primary afferent feedback. The parameters of the primary afferent model were altered systematically to evaluate the effect of fusimotor drive. The experimental and simulated data were analyzed with hierarchical clustering. We found that the muscle activity patterns contained flexible task-dependent groups that consisted of co-activating agonistic and antagonistic muscles that changed with the dynamics of the task. The activity of muscles spanning only the shoulder generally grouped into a proximal cluster, while the muscles spanning the wrist grouped into a distal cluster. The bifunctional muscle spanning the shoulder and elbow were flexibly grouped with either proximal or distal cluster based on the dynamical requirements of the task. The composition and activation of these groups reflected the relative contribution of active and passive forces to each motion. In contrast, the simulated primary afferent feedback was most related to joint kinematics rather than dynamics, even though the primary afferent models had nonlinear dynamical components and variable fusimotor drive. Simulated physiological changes to the fusimotor drive were not sufficient to reproduce the dynamical features in muscle activity pattern. Altogether, these results suggest that sensory feedback signals are in a different domain from that of muscle activation signals. This indicates that to solve the neuromechanical problem, the central nervous system controls limb dynamics through task-dependent co-activation of muscles and non-linear modulation of monosynaptic primary afferent feedback.New & NoteworthyHere we answered the fundamental question in sensorimotor transformation of how primary afferent signals can contribute to the compensation for limb dynamics evident in muscle activity. We combined computational and experimental approaches to create a new experimental paradigm that challenges the nervous system with passive limb dynamics that either assists or resists the desired movement. We found that the active dynamical features present in muscle activity are unlikely to arise from direct feedback from primary afferents.

scholarly journals Functional changes in the temporomandibular joint mechanoreceptors associated with experimentally induced condylar resorption in rats

2020 ◽  
Vol 90 (6) ◽  
pp. 831-836
Author(s):  
Satomi Naito ◽  
Chiho Kato ◽  
Tadachika Yabushita ◽  
Takashi Ono
Keyword(s):  
Temporomandibular Joint ◽  
Single Unit ◽  
Compressive Force ◽  
Firing Frequency ◽  
Control Group ◽  
Gasserian Ganglion ◽  
Firing Threshold ◽  
Functional Changes ◽  
Force Loading ◽  
Experimentally Induced

ABSTRACT Objectives To evaluate the influence of experimentally induced progressive condylar resorption (PCR) on temporomandibular joint (TMJ) mechanoreception. Materials and Methods Twenty 13-week-old male albino Wistar rats were divided equally into control and PCR groups. A compressive force was loaded on the left TMJ of PCR group rats to induce condylar resorption. Single-unit activities of TMJ mechanoreceptors were also induced through passive jaw movement. Recording was performed for the left Gasserian ganglion at 3 days and 1 week after the establishment of PCR group. The effects of PCR on TMJ units were assessed by measuring the firing threshold, maximum instantaneous firing frequency, and average firing frequency. Results Compared with the control group, there were no significant differences in the firing threshold of the PCR group after 3 days. The thresholds were significantly higher 1 week after compressive force loading on the condyle. The maximum instantaneous firing frequencies and the average firing frequencies showed no significant differences after 3 days. However, these were significantly lower 1 week after compressive force loading. Conclusions The findings suggest that compressive force loading on the condyle may influence the function of TMJ mechanoreceptors.

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