Lateralized phrenic nerve responses to stimulating respiratory afferents in the cat

1976 ◽  
Vol 230 (5) ◽  
pp. 1314-1320 ◽  
Author(s):  
AJ Berger ◽  
RA Mitchell
Keyword(s):  
Phrenic Nerve ◽  
Carotid Sinus ◽  
Short Latency ◽  
Evoked Response ◽  
Internal Branch ◽  
Reflex Pathway ◽  
Low Intensity ◽  
Inspiratory Neurons ◽  
Pharyngeal Branch ◽  
Stimulation Of

We stimulated electrically pharyngeal branch of both glossopharyngeal nerves (PGLN), internal branch of superior laryngeal nerves (ISLN), and carotid sinus nerves (CSN) in anesthetized cats. We recorded simultaneously, averaged, and compared bilaterally evoked phrenic nerve (PHR) activity. Our objective was to demonstrate a short-latency evoked response in the PHR contralateral to the stimulus. Low-intensity stimulation of PGLN and ISLN during inspiration evoked a short-latency contralateral excitation with a latency of 5.2 ms +/- 0.2 SE (16 cats) for PGLN, and 3.8 ms +/- 0.1 SE (13 cats) for ISLN. This excitation could follow stimuli delivered at 100 Hz. Stimulation during expiration did not result in a lateralized excitation. The excitation is followed by bilateral inhibition. Neither strychnine nor picrotoxin prevented either the lateralized response or the inhibition, though strychnine diminished a delayed bilateral excitation following PGLN stimulation. This dalayed (latency 18.7 ms +/- 0.7 SE) bilateral excitation corresponds to the sniff reflex. CSN stimulation did not result in lateralized excitation. We suggest that the lateralized evoked response results from a gated paucisynaptic reflex pathway involving the PGLN and ISLN, ipsilateral inspiratory neurons, and contralateral PHR motoneurons.

Respiratory motor responses to cranial nerve afferent stimulation in rats

1996 ◽  
Vol 271 (4) ◽  
pp. R1054-R1062 ◽  
Author(s):  
F. Hayashi ◽  
D. R. McCrimmon
Keyword(s):  
Cranial Nerve ◽  
Superior Laryngeal Nerve ◽  
Single Pulse ◽  
Short Latency ◽  
Lung Inflation ◽  
Dorsal Respiratory Group ◽  
Inspiratory Activity ◽  
Pharyngeal Branch ◽  
Pulse Stimulation ◽  
Stimulation Of

It was hypothesized that, because rats appear to lack a prominent disynaptic projection from the dorsal respiratory group to phrenic motoneurons (Phr), they would lack the short-latency excitation of Phr output seen in cats in response to stimulation of some cranial nerve afferents. Single-pulse superior laryngeal nerve (SLN) stimulation elicited a short-latency bilateral excitation of glossopharyngeal (IX) and hypoglossal (XII) nerves and an ipsilateral excitation of pharyngeal branch of vagus (PhX) in 67% of rats, but no excitation of Phr. Vagus (X) stimulation elicited a bilateral excitation of Phr and a predominantly ipsilateral excitation of IX and PhX. Single-pulse stimulation of SLN or X also elicited longer-latency, bilateral decreases in activity of all recorded nerves. Repetitive stimulation (50 Hz) of SLN or X suppressed inspiratory activity and prolonged expiration. Lung inflation (7.5 cmH2O) inhibited Phr and PhX activity; X stimulation inhibited Phr but prolonged PhX activity. In conclusion, rats predictably lack the SLN-induced short latency Phr excitation but exhibit other short latency reflexes for which the underlying circuitry is not clear.

Baroreflex Sensitivity Assessment – Latest Advances and Strategies

2011 ◽  
Vol 7 (2) ◽  
pp. 89 ◽  
Author(s):  
Maria Teresa La Rovere ◽  
Roberto Maestri ◽  
Gian Domenico Pinna ◽  
◽  
◽  
...  
Keyword(s):  
Baroreflex Sensitivity ◽  
Carotid Sinus ◽  
Lower Blood Pressure ◽  
Vasomotor Tone ◽  
Sensitivity Assessment ◽  
Lower Blood ◽  
Prognostic Implications ◽  
Novel Therapeutic Strategies ◽  
Sympathetic Vasomotor Tone ◽  
Stimulation Of

The baroreflex mechanism has been recognised as a key part of cardiovascular regulation. Alterations in the baroreceptor-heart rate reflex (baroreflex sensitivity [BRS]) contribute to sympathetic–parasympathetic imbalance, playing a major role in the development and progression of many cardiovascular disorders. Therefore, the measurement of the baroreflex is a source of valuable information in the clinical management of cardiac disease patients. This article reviews the most relevant advances for the measurement of BRS and their clinical and prognostic implications. Novel therapeutic strategies, exploring the use of electrical stimulation of the carotid sinus, have been evaluated recently in experimental and preliminary clinical studies to lower blood pressure and to reduce the level of baroreflex-mediated sympathoexcitation in heart failure. A recent study has also shown that the implementation of an artificial baroreflex system to regulate sympathetic vasomotor tone automatically is feasible.

Electrical stimulation of the carotid sinus lowers arterial pressure and improves heart rate variability in l-NAME hypertensive conscious rats

2020 ◽  
Vol 43 (10) ◽  
pp. 1057-1067 ◽  
Author(s):  
Gean Domingos-Souza ◽  
Fernanda Machado Santos-Almeida ◽  
César Arruda Meschiari ◽  
Nathanne S. Ferreira ◽  
Camila A. Pereira ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Electrical Stimulation ◽  
Arterial Pressure ◽  
Carotid Sinus ◽  
Conscious Rats ◽  
Stimulation Of

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.

scholarly journals Assessment of magnetic flux density properties of electromagnetic noninvasive phrenic nerve stimulations for environmental safety in an ICU environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
K. Friedrich Kuhn ◽  
Julius J. Grunow ◽  
Pascal Leimer ◽  
Marco Lorenz ◽  
David Berger ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Magnetic Flux ◽  
Flux Density ◽  
Muscle Fiber ◽  
Phrenic Nerve ◽  
Magnetic Flux Density ◽  
Training Center ◽  
Electromagnetic Stimulation ◽  
Stimulation Of

AbstractDiaphragm weakness affects up to 60% of ventilated patients leading to muscle atrophy, reduction of muscle fiber force via muscle fiber injuries and prolonged weaning from mechanical ventilation. Electromagnetic stimulation of the phrenic nerve can induce contractions of the diaphragm and potentially prevent and treat loss of muscular function. Recommended safety distance of electromagnetic coils is 1 m. The aim of this study was to investigate the magnetic flux density in a typical intensive care unit (ICU) setting. Simulation of magnetic flux density generated by a butterfly coil was performed in a Berlin ICU training center with testing of potential disturbance and heating of medical equipment. Approximate safety distances to surrounding medical ICU equipment were additionally measured in an ICU training center in Bern. Magnetic flux density declined exponentially with advancing distance from the stimulation coil. Above a coil distance of 300 mm with stimulation of 100% power the signal could not be distinguished from the surrounding magnetic background noise. Electromagnetic stimulation of the phrenic nerve for diaphragm contraction in an intensive care unit setting seems to be safe and feasible from a technical point of view with a distance above 300 mm to ICU equipment from the stimulation coil.

Activation of thalamic ventroposteriolateral neurons by phrenic nerve afferents in cats and rats

2003 ◽  
Vol 94 (1) ◽  
pp. 220-226 ◽  
Author(s):  
Weirong Zhang ◽  
Paul W. Davenport
Keyword(s):  
Electrical Stimulation ◽  
Somatosensory Cortex ◽  
Phrenic Nerve ◽  
Proprioceptive Information ◽  
Neural Responses ◽  
Afferent Stimulation ◽  
Physiological Conditions ◽  
Sensory Pathways ◽  
Increased Activity ◽  
Stimulation Of

It has been demonstrated that phrenic nerve afferents project to somatosensory cortex, yet the sensory pathways are still poorly understood. This study investigated the neural responses in the thalamic ventroposteriolateral (VPL) nucleus after phrenic afferent stimulation in cats and rats. Activation of VPL neurons was observed after electrical stimulation of the contralateral phrenic nerve. Direct mechanical stimulation of the diaphragm also elicited increased activity in the same VPL neurons that were activated by electrical stimulation of the phrenic nerve. Some VPL neurons responded to both phrenic afferent stimulation and shoulder probing. In rats, VPL neurons activated by inspiratory occlusion also responded to stimulation on phrenic afferents. These results demonstrate that phrenic afferents can reach the VPL thalamus under physiological conditions and support the hypothesis that the thalamic VPL nucleus functions as a relay for the conduction of proprioceptive information from the diaphragm to the contralateral somatosensory cortex.

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