Reflex Responses in Human Jaw, Lip, and Tongue Muscles Elicited by Mechanical Stimulation

1987 ◽  
Vol 30 (1) ◽  
pp. 70-79 ◽  
Author(s):  
Christine M. Weber ◽  
Anne Smith
Keyword(s):  
Mechanical Stimuli ◽  
Observable Effect ◽  
Direct Stimulation ◽  
Muscle Spindle Afferents ◽  
Lower Lip ◽  
Reflex Responses ◽  
Reflex Pathways ◽  
Tongue Muscles ◽  
Jaw Muscle ◽  
Stimulation Of

Reflex responses in human jaw, lip, and tongue muscles were elicited with brief, innocuous mechanical stimuli. Stimuli were applied to the masseter (and overlying tissue), the lower lip vermilion, and the tongue dorsum. Reflex responses occurred in masseter, orbicularis oris inferior, and genioglossus muscles upon direct stimulation of the sites associated with each of these muscles. In contrast, reflex responses to stimulation of "distant" sites occurred almost exclusively in masseter; that is, stimulation of the lip and tongue produced responses in masseter, but, stimulation of jaw muscle spindle afferents and overlying cutaneous receptors had no observable effect on activity in genioglossus or orbicularis oris inferior muscles. It could be hypothesized that the motoneuron pools controlling jaw muscles are more sensitive to synaptic inputs generated by reflex pathways originating in other structures. The sensitivity of the masseter muscle to inputs from the lip and tongue may serve to link these structures functionally.

scholarly journals Focal Laser Stimulation of Fly Nociceptors Activates Distinct Axonal and Dendritic Ca2+ Signals

2021 ◽  
Author(s):  
Rajshekhar Basak ◽  
Sabyasachi Sutradhar ◽  
Jonathon Howard
Keyword(s):  
Morphological Changes ◽  
Mechanical Stimuli ◽  
Direct Stimulation ◽  
Calcium Signals ◽  
Precise Position ◽  
Contact Pathway ◽  
Contact Response ◽  
Escape Behaviors ◽  
Class Iv ◽  
Stimulation Of

Drosophila Class IV neurons are polymodal nociceptors that detect noxious mechanical, thermal, optical and chemical stimuli. Escape behaviors in response to attacks by parasitoid wasps are dependent on Class IV cells, whose highly branched dendritic arbors form a fine meshwork that is thought to enable detection of the wasp's needle-like ovipositor barb. To understand how mechanical stimuli trigger cellular responses, we used a focused 405-nm laser to create highly local lesions to probe the precise position needed in evoke responses. By imaging calcium signals in dendrites, axons, and soma in response to stimuli of varying positions, intensities and spatial profiles, we discovered that there are two distinct nociceptive pathways. Direct stimulation to dendrites (the contact pathway) produces calcium responses in axons, dendrites and the cell body whereas stimulation adjacent to the dendrite (the non-contact pathway) produces calcium responses in the axons only. We interpret the non-contact pathway as damage to adjacent cells releasing diffusible molecules that act on the dendrites. Axonal responses have higher sensitivities and shorter latencies. In contrast, dendritic responses have lower sensitivities and longer latencies. Stimulation of finer, distal dendrites leads to smaller responses than stimulation of coarser, proximal dendrites, as expected if the contact response depends on the geometric overlap of the laser profile and the dendrite diameter. Because the axon signals to the CNS to trigger escape behaviors, we propose that the density of the dendritic meshwork is high not only to enable direct contact with the ovipositor, but also to enable neuronal activation via diffusing signals from damaged surrounding cells. Dendritic contact evokes responses throughout the dendritic arbor, even to regions distant and distal from the stimulus. These dendrite-wide calcium signals may facilitate hyperalgesia or cellular morphological changes following dendritic damage.

Asymmetry in reflex responses of nasal muscles in anesthetized guinea pigs

1998 ◽  
Vol 85 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Shin-Ichi Sekizawa ◽  
Teruhiko Ishikawa ◽  
Giuseppe Sant’Ambrogio
Keyword(s):  
Electrical Stimulation ◽  
Nasal Cavity ◽  
Guinea Pigs ◽  
Contralateral Side ◽  
Mechanical Stimuli ◽  
Reflex Responses ◽  
Two Sides ◽  
Nasal Muscles ◽  
Stimulation Of ◽  
Expired Air

Nasal reflexes elicited by mechanical or electrical stimulation of nasal afferents were studied in anesthetized guinea pigs. Probing the nasal cavity of one side evoked a greater activation of the contralateral than the ipsilateral nasal muscles and, occasionally, sneezing. Similarly, electrical stimulation of the ethmoidal nerve often caused sneezing, with a greater activation of the nasal muscles and a greater increase in resistance on the contralateral side. Asymmetrical activation of the nasal muscles in response to mechanical stimuli induces asymmetrical airflows, especially during sneezing, between the two sides of the nasal cavity. Most of the expired air is forcibly blown out through the ipsilateral nostril, thus improving the elimination of irritants from the nose.

Coordinated Interlimb Compensatory Responses to Electrical Stimulation of Cutaneous Nerves in the Hand and Foot During Walking

2003 ◽  
Vol 90 (5) ◽  
pp. 2850-2861 ◽  
Author(s):  
Carlos Haridas ◽  
E. Paul Zehr
Keyword(s):  
Electrical Stimulation ◽  
Motor Coordination ◽  
The Body ◽  
Emg Activity ◽  
Motor Tasks ◽  
Step Cycle ◽  
Reflex Responses ◽  
Cutaneous Reflex ◽  
Reflex Pathways ◽  
Stimulation Of

It has been shown that stimulation of cutaneous nerves innervating the hand (superficial radial, SR) and foot (superficial peroneal, SP) elicit widespread reflex responses in many muscles across the body. These interlimb reflex responses were suggested to be functionally relevant to assist in motor coordination between the arms and legs during motor tasks such as walking. The experiments described in this paper were conducted to test the hypothesis that interlimb reflexes were phase-dependently modulated and produced functional kinematic changes during locomotion. Subjects walked on a treadmill while electromyographic (EMG) activity was collected continuously from all four limbs, and kinematic recordings were made of angular changes across the ankle, knee, elbow, and shoulder joints. Cutaneous reflexes were evoked by delivering trains of electrical stimulation pseudorandomly to the SP nerve or SR nerves in separate trials. Reflexes were phase-averaged according to the time of occurrence in the step cycle, and phasic amplitudes and latencies were calculated. For both nerves, significant phase-dependent modulation (including reflex reversals) of interlimb cutaneous reflex responses was seen in most muscles studied. Both SR and SP nerve stimulation resulted in significant alteration in ankle joint kinematics. The results suggest coordinated and functionally relevant reflex pathways from the SP and SR nerves onto motoneurons innervating muscles in nonstimulated limbs during walking, thus extending observations from the cat to that of the bipedal human.

Trigemino-Bulbar Reflex Pathways

1957 ◽  
Vol 189 (2) ◽  
pp. 384-388 ◽  
Author(s):  
John D. Green ◽  
Jacob De Groot ◽  
Jerome Sutin
Keyword(s):  
Heart Rate ◽  
Dura Mater ◽  
Trigeminal Nerve ◽  
Cranial Nerves ◽  
Nucleus Ambiguus ◽  
Direct Stimulation ◽  
Reflex Pathways ◽  
The Face ◽  
Vagal Reflex ◽  
Stimulation Of

In decerebrate and decerebellate cats stimulation of any division of the trigeminal nerve induces efferent volleys in the VIIth, Xth, XIth and XIIth nerves. Direct stimulation of the face, internal nares and dura mater produces similar volleys. In uncurarized animals similar stimuli cause twitches of face and neck muscles. Slowing of the heart rate may also be induced. Conduction times measured in the brainstem and cranial nerves show that conduction is very rapid in the brainstem to the level of the obex, so that large medullated fibers may be inferred. At the level of the obex a delay of 2–4 msec. occurs, presumably due to synapses and internuncial neurones. Conduction of the volleys in the Xth and XIth nerves is rapid and large fibers must be involved. Removal of the dorsal vagal nuclei does not abolish the vagal reflex which is presumed to relay at the nucleus ambiguus. The vagal responses are very easily fatigued.

Direct and relayed projection of periodontal receptor afferents to the cerebellum in the ferret

1987 ◽  
Vol 231 (1263) ◽  
pp. 199-216 ◽  
Keyword(s):  
Cerebellar Cortex ◽  
Evidence Based ◽  
Field Potentials ◽  
Muscle Spindle Afferents ◽  
Latency Analysis ◽  
Jaw Muscle ◽  
To Come ◽  
Periodontal Afferent ◽  
Mossy Fibres ◽  
Stimulation Of

Field potentials in the cerebellar cortex of the ferret have been studied in response to stimulation of alveolar, muscular and cutaneous branches of the trigeminal nerve. Responses from the alveolar nerves are unusual in their very short latency. Evidence based on latency analysis, frequency following and comparison with other well-known inputs supports the view that the earliest field potentials are due to direct, unrelayed afferents, which terminate as mossy fibres. There is, in addition, a monosynaptically relayed afferent path via mossy fibres. The alveolar nerve afferents concerned with the direct projection are shown to come from periodontal mechanoreceptors and not from cutaneous receptors. No such connections are found from jaw-muscle spindle afferents. The direct and relayed periodontal pathways are both ipsilateral and crossed. They terminate in the cerebellar cortex in the parvermal region of lobules IV, V and VI. The functional significance of the direct periodontal afferent projection is considered particularly in the light of parallels with the vestibular system, which also has direct and relayed cerebellar projections.

Changes of the Jaw Opening Reflex Activity by Electroacupuncture Stimulation in Rat

1981 ◽  
Vol 09 (03) ◽  
pp. 236-242 ◽  
Author(s):  
Kazuo Toda
Keyword(s):  
Tooth Pulp ◽  
Spinal Trigeminal Nucleus ◽  
Trigeminal Nucleus ◽  
Direct Stimulation ◽  
Lower Lip ◽  
Jaw Opening ◽  
Jaw Opening Reflex ◽  
Sensory Pathway ◽  
Main Action ◽  
Stimulation Of

After electroacupuncture stimulation applied to bilateral Ho-Ku points in the rat forepaw, jaw opening reflex to tooth pulp stimulation was fairly suppressed, but that to gingiva, upper lip or lower lip stimulation was scarely affected. By direct stimulation of afferent sensory pathway in the spinal trigeminal nucleus, jaw opening reflex was also evoked. Suppressive effects of electroacupuncture were more markedly observed when the jaw opening reflex was evoked by stimulating the caudal part of the spinal trigeminal nucleus than when the reflex was evoked by stimulation of the rostral area of the nucleus. One of the main action sites of the electroacupuncture on the jaw opening reflex was the caudal spinal trigeminal nucleus, which is the secondary neuron level in the trigeminal noxious sensory pathway, suggesting that electroacupuncture can provoke the pain suppressive effects strongly in the lower part of the brain with the higher brain function being intact. Therefore, this observation is thought to be well coincident with clinical data that acupuncture produces analgesia without affecting patients' consciousness during surgical operations.

Reflex responses evoked from cats' coccygeal ventral roots by electrical stimulation of the tail nerves

1987 ◽  
Vol 96 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Margarita Martinez-Gomez ◽  
Pablo Pacheco ◽  
Bernardo Dubrovsky
Keyword(s):  
Electrical Stimulation ◽  
Reflex Responses ◽  
Ventral Roots ◽  
Stimulation Of

scholarly journals The Role of BMP Signaling in Osteoclast Regulation

2021 ◽  
Vol 9 (3) ◽  
pp. 24
Author(s):  
Brian Heubel ◽  
Anja Nohe
Keyword(s):  
Bone Formation ◽  
Bone Morphogenetic Proteins ◽  
Bone Diseases ◽  
Bmp Signaling ◽  
Bone Homeostasis ◽  
Direct Stimulation ◽  
Federal Drug Administration ◽  
Bmp Pathway ◽  
Stimulation Of

The osteogenic effects of Bone Morphogenetic Proteins (BMPs) were delineated in 1965 when Urist et al. showed that BMPs could induce ectopic bone formation. In subsequent decades, the effects of BMPs on bone formation and maintenance were established. BMPs induce proliferation in osteoprogenitor cells and increase mineralization activity in osteoblasts. The role of BMPs in bone homeostasis and repair led to the approval of BMP2 by the Federal Drug Administration (FDA) for anterior lumbar interbody fusion (ALIF) to increase the bone formation in the treated area. However, the use of BMP2 for treatment of degenerative bone diseases such as osteoporosis is still uncertain as patients treated with BMP2 results in the stimulation of not only osteoblast mineralization, but also osteoclast absorption, leading to early bone graft subsidence. The increase in absorption activity is the result of direct stimulation of osteoclasts by BMP2 working synergistically with the RANK signaling pathway. The dual effect of BMPs on bone resorption and mineralization highlights the essential role of BMP-signaling in bone homeostasis, making it a putative therapeutic target for diseases like osteoporosis. Before the BMP pathway can be utilized in the treatment of osteoporosis a better understanding of how BMP-signaling regulates osteoclasts must be established.

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