scholarly journals Anatomy and neuro-pathophysiology of the cough reflex arc

2012 ◽  
Vol 7 ◽  
Author(s):  
Mario Polverino ◽  
Francesca Polverino ◽  
Marco Fasolino ◽  
Filippo Andò ◽  
Antonio Alfieri ◽  
...  
Keyword(s):  
General Practitioner ◽  
Cough Reflex ◽  
Defensive Reflex ◽  
Reflex Arc ◽  
Stimulation Of

Coughing is an important defensive reflex that occurs through the stimulation of a complex reflex arc. It accounts for a significant number of consultations both at the level of general practitioner and of respiratory specialists. In this review we first analyze the cough reflex under normal conditions; then we analyze the anatomy and the neuro-pathophysiology of the cough reflex arc. The aim of this review is to provide the anatomic and pathophysiologic elements of evaluation of the complex and multiple etiologies of cough.

Supraspinal inhibition of a cutaneous vascular reflex in the cat

1964 ◽  
Vol 207 (2) ◽  
pp. 303-307 ◽  
Author(s):  
B. J. Prout ◽  
J. H. Coote ◽  
C. B. B. Downman
Keyword(s):  
Carotid Sinus ◽  
Spinal Reflexes ◽  
Descending Pathways ◽  
Skin Response ◽  
Reflex Arc ◽  
Vascular Reflex ◽  
Carotid Sinus Nerve Stimulation ◽  
Sympathetic Discharge ◽  
Stimulation Of ◽  
Cerebellar Stimulation

In cats anesthetized with chloralose-urethane mixture, stimulation of an afferent nerve evoked a vasoconstrictor reflex (VCR) and a galvanic skin response (GSR) in the pads of the feet. Stimulation of the ventromedial medullary reticular substance at the level of the obex abolished the VCR and the GSR. VCR could also be reduced by occlusion during prolonged stimulation of another spinal or visceral afferent pathway. Medulla stimulation was effective without itself causing a sympathetic discharge to the paw, showing that inhibition rather than occlusion was operative. Anterior cerebellar stimulation also inhibited the VCR. Carotid sinus nerve stimulation did not abolish the VCR. It is concluded that the effective mechanism includes a bulbospinal inhibitory path projecting on a spinal vasoconstrictor reflex arc. This arrangement is similar to the descending pathways inhibiting other spinal reflexes but the VCR-inhibitory path can be activated independently of them.

Deep Inspiration-Provoked Cough: A Sign of Cough Reflex Arc Hypersensitivity

Lung ◽  
2021 ◽  
Author(s):  
Heikki O. Koskela ◽  
Hanna M. Nurmi ◽  
Woo-Jung Song
Keyword(s):  
Deep Inspiration ◽  
Cough Reflex ◽  
Reflex Arc

Utriculoocular reflex arc of the cat

1996 ◽  
Vol 76 (3) ◽  
pp. 1896-1903 ◽  
Author(s):  
Y. Uchino ◽  
M. Sasaki ◽  
H. Sato ◽  
M. Imagawa ◽  
H. Suwa ◽  
...  
Keyword(s):  
Head Tilt ◽  
Vestibular Nuclei ◽  
Intracellular Recordings ◽  
Additional Increase ◽  
Extraocular Motoneurons ◽  
Eye Rotation ◽  
Reflex Arc ◽  
Supramaximal Stimulation ◽  
Utricular Nerve ◽  
Stimulation Of

1. Intracellular recordings of synaptic potentials in extraocular motoneurons were studied to determine the connectivities between the utricular nerve and the extraocular motoneurons in cats. 2. Stimulating electrodes were placed within the left utricular nerve, while other branches of the vestibular nerve were removed. Subsequently, the N1 field potentials evoked by utricular nerve stimulation were recorded in the vestibular nuclei. The potential typically grew until reaching a plateau (submaximal stimulation). Stimulus spread to the other nerve branches appeared as an additional increase in N1 amplitude after the plateau discontinued (supramaximal stimulation). 3. Intracellular recordings were made from 200 identified motoneurons in the bilateral III, IV, and VI cranial nuclei. 4. Stimulation of the utricular nerve at submaximal intensity evoked a longer latency depolarizing and hyperpolarizing potentials in contra- and ipsilateral medial rectus motoneurons, respectively. Complex potentials with longer latencies also were recorded in ipsilateral inferior oblique and contralateral trochlear motoneurons after stimulation of the utricular nerve at a submaximal intensity. Monosynaptic and disynaptic connections between the utricular nerve and ipsilateral abducens motoneurons and interneurons were recorded as described previously. 5. The results of the present study confirm our initial findings that a disynaptic pathway from the utricular nerve to contralateral trochlear motoneurons is absent or very poorly developed, whereas polysynaptic circuits from the utricular nerve to inferior oblique and trochlear motoneurons may play a role in eye rotation during head tilt.

Stimulation of the cough reflex

1968 ◽  
Vol 17 (5) ◽  
pp. 473
Author(s):  
JOAN E. HEDGES ◽  
CAROLYN J. BRIDGES ◽  
L. Christman
Keyword(s):  
Cough Reflex ◽  
Stimulation Of

The Effect of Local Anaesthesia of the Airway on Respiratory Reflexes in the Rabbit

1973 ◽  
Vol 44 (6) ◽  
pp. 519-538 ◽  
Author(s):  
S. K. Jain ◽  
Diana Trenchard ◽  
Felicity Reynolds ◽  
M. I. M. Noble ◽  
A. Guz
Keyword(s):  
Ventilatory Response ◽  
Plasma Concentrations ◽  
Systemic Effects ◽  
Pathological Changes ◽  
Vagus Nerves ◽  
Cough Reflex ◽  
Alveolar Level ◽  
Toxic Concentrations ◽  
Respiratory Reflexes ◽  
Stimulation Of

1. The effect of breathing anaesthetic aerosols (lignocaine 20% and bupivacaine 5%) on respiratory reflexes was studied in rabbits. 2. The cough reflex was blocked in every experiment. 3. The inflation reflex was abolished in eleven out of twenty-six rabbits given lignocaine aerosol and in fourteen out of fifteen rabbits given bupivacaine aerosol. 4. The deflation reflex was blocked pari passu with the inflation reflex. 5. The ventilatory response to histamine was sometimes blocked; more commonly it was partially preserved. 6. The ventilatory response to phenyldiguanide was never impaired and often enhanced. 7. Bronchoconstriction produced by electrical stimulation of the peripheral cut ends of the cervical vagus nerves was unaffected. 8. Block of the above respiratory reflexes was associated with slower, deeper breathing. 9. Bupivacaine has produced more consistent and reliable results than lignocaine; the effects were reversible in both cases usually within 30 min. 10. Plasma concentrations of both anaesthetics were usually below the generally accepted toxic concentrations in man. 11. Control experiments using intravenous infusions of the anaesthetics proved that none of the effects could have been produced by systemic effects of the absorbed anaesthetic. 12. No pathological changes were found in the airways on both macroscopic and microscopic examination. 13. The experiments show that it is possible to block respiratory reflexes whose afferents arise from the airways, and to preserve a reflex arising at alveolar level.

Stimulation of vagal afferents inhibits locomotion in mesencephalic cats

1993 ◽  
Vol 74 (1) ◽  
pp. 103-110 ◽  
Author(s):  
J. G. Pickar ◽  
J. M. Hill ◽  
M. P. Kaufman
Keyword(s):  
Intravenous Injection ◽  
Left Atrial ◽  
Onset Time ◽  
Vagal Afferents ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
C Fibers ◽  
Cervical Vagotomy ◽  
Reflex Arc ◽  
Stimulation Of

Using electrical stimulation of the mesencephalic locomotor region, we made decerebrate unanesthetized cats walk on a treadmill. The locomotion induced by stimulation of this midbrain area was assessed before and during activation of vagal afferents by either intravenous injection of phenylbiguanide or inflation of a balloon placed in the left atrium. Inflation of a balloon, which increased left atrial pressure by 7–25 mmHg, abolished locomotion in 9 of 10 cats tested. Bilateral cervical vagotomy prevented the abolition of locomotion by balloon inflation in each of two cats tested. Intravenous phenylbiguanide (50 or 100 micrograms/kg) or serotonin (40 micrograms/kg) injections abolished or attenuated walking induced by midbrain stimulation in 11 of 13 cats tested. In addition, intravenous phenylbiguanide injections abolished or attenuated locomotion with a shorter onset time than did systemic injections of this substance in five of six cats tested. Bilateral cervical vagotomy prevented the abolition of locomotion by phenylbiguanide injection in each of five cats tested. We conclude that locomotion can be prevented by a viscerosomatic reflex arising from the lungs and heart. The afferent arm of this reflex arc is the vagus nerve. Afferents such as slowly and rapidly adapting pulmonary stretch receptors, atrial receptors, and lung C-fibers may have had a role in preventing locomotion during the increase in left atrial pressure in our experiments. On the other hand, pulmonary C-fibers had a crucial role in preventing locomotion during intravenous injection of phenyl-biguanide. We speculate that this viscerosomatic reflex may help to explain in part the intolerance for exercise displayed by patients with congestive heart failure.

Inhibition of respiratory reflexes by local anesthetic aerosols in dogs and rabbits

1975 ◽  
Vol 38 (6) ◽  
pp. 1045-1050 ◽  
Author(s):  
D. S. Dain ◽  
H. A. Boushey ◽  
W. M. Gold
Keyword(s):  
Electrical Stimulation ◽  
Local Anesthetic ◽  
Nervous Activity ◽  
Smooth Muscles ◽  
Vagus Nerves ◽  
Cough Reflex ◽  
Bupivacaine Hydrochloride ◽  
Anesthetized Dogs ◽  
Respiratory Reflexes ◽  
Stimulation Of

The effects of inhalation of 100 breaths of bupivacaine hydrochloride (5 percent solution in saline) on the cough reflex, the Breuer-Hering inflation, reflex, and the duration of apnea and bronchoconstriction produced by histamine aerosol were studied in nine anesthetized dogs. Cough was abolished in every animal; the duration of the inflation reflex was shortened from 47 +/- 4.6 s (mean plus or minus SE) to 16 +/- 3.4 s. The duration apnea produced by histamine was abolished or shortened and the rise in resistance was diminished from 170 plus or minus 22 per cent (control) to 49 +/- 6 per cent (after bupivacaine). These reflexes returned toward control values within 45 min. Bupivacaine inhibited the bronchoconstriction produced by electrical stimulation of the distal ends of cut vagus nerves both in dogs and in rabbits, but it did not alter the rise in resistance produced by histamine aerosol in vagotomized dogs. We conclude that administration of bupivacaine aerosol produces a reversible blockage of both afferent and efferent nervous activity in airways without abolishing the ability of smooth muscles to contract.

scholarly journals Cough-provocation tests with hypertonic aerosols

2020 ◽  
Vol 6 (2) ◽  
pp. 00338-2019
Author(s):  
Heikki O. Koskela ◽  
Hanna M. Nurmi ◽  
Minna K. Purokivi
Keyword(s):  
Chronic Cough ◽  
Smooth Muscles ◽  
Clinical Importance ◽  
Clinical Work ◽  
Special Equipment ◽  
Cough Reflex ◽  
Provocation Tests ◽  
Related Quality ◽  
Reflex Arc ◽  
Long Term Prognosis

Recent advances in cough research suggest a more widespread use of cough-provocation tests to demonstrate the hypersensitivity of the cough reflex arc. Cough-provocation tests with capsaicin or acidic aerosols have been used for decades in scientific studies. Several factors have hindered their use in everyday clinical work: i.e. lack of standardisation, the need for special equipment and the limited clinical importance of the response. Cough-provocation tests with hypertonic aerosols (CPTHAs) involve provocations with hypertonic saline, hypertonic histamine, mannitol and hyperpnoea. They probably act via different mechanisms than capsaicin and acidic aerosols. They are safe and well tolerated and the response is repeatable. CPTHAs can assess not only the sensitivity of the cough reflex arc but also the tendency of the airway smooth muscles to constrict (airway hyper-responsiveness). They can differentiate between subjects with asthma or chronic cough and healthy subjects. The responsiveness to CPTHAs correlates with the cough-related quality of life among asthmatic subjects. Furthermore, the responsiveness to them decreases during treatment of chronic cough. A severe response to CPTHAs may indicate poor long-term prognosis in chronic cough. The mannitol test has been stringently standardised, is easy to administer with simple equipment, and has regulatory approval for the assessment of airway hyper-responsiveness. Manual counting of coughs during a mannitol challenge would allow the measurement of the function of the cough reflex arc as a part of clinical routine.

Reflex Control of Nasal Blood Vessels

1987 ◽  
Vol 96 (3) ◽  
pp. 273-277 ◽  
Author(s):  
Shigeki Nishihira ◽  
Thomas V. Mccaffrey
Keyword(s):  
Blood Vessels ◽  
Nasal Mucosa ◽  
Vagus Nerves ◽  
Lung Inflation ◽  
Afferent Fibers ◽  
Reflex Arc ◽  
Capacitance Vessels ◽  
Nasal Blood Vessels ◽  
Pulmonary Stretch Receptor ◽  
Stimulation Of

The effect of stimulation of vagal afferent fibers on nasal blood vessels was studied in 36 cats. Volume change of the nasal capacitance vessels was measured by plethysmographic balloons inserted into the nose. Electrical stimulation of the vagus nerve produced a vasodilatation of nasal mucosa. Pulmonary stretch receptor stimulation by veratridine alkaloid and progressive lung inflation in open-chest cats also produced a vasodilatation of the nasal mucosa. These reflexes were abolished by sectioning the vagus nerves. These results suggest a reflex arc between the lung and nasal capacitance vessels which arises from pulmonary stretch receptors.

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