Synchronization of Respiratory Rhythm with Electrical Stimulation of the Phrenic Nerve

1978 ◽  
Vol BME-25 (6) ◽  
pp. 550-554 ◽  
Author(s):  
Makoto Noshiro ◽  
Shoji Suzuki
2003 ◽  
Vol 94 (1) ◽  
pp. 220-226 ◽  
Author(s):  
Weirong Zhang ◽  
Paul W. Davenport

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.


1996 ◽  
Vol 76 (4) ◽  
pp. 2393-2401 ◽  
Author(s):  
N. Buonviso ◽  
M. A. Chaput ◽  
F. Berthommier

1. Neighboring mitral/tufted cells have been previously shown to present temporal correlations of their firings related to the respiratory rhythm, particularly under odor stimulation. This occurs despite the existence of a powerful inhibitory control exerted by granule cells onto mitral/tufted cells. In the present study, we hypothesized that neighboring mitral cells can present granular induced inhibitory periods with similar latencies and durations and that such a similarity would preserve them from a possible suppression of their temporal correlations. 2. To test this hypothesis, we analyzed the latencies and durations of the inhibitory periods induced by granular activation in pairs of simultaneously recorded neighboring mitral cells. The activation of granule cells was achieved by electrical stimulation of the different pathways known to directly activate granule cells [lateral olfactory tract (LOT), anterior limb of the anterior commissure (AC), and piriform cortex (PC)]. Data from this group were compared with those of a control group composed of distant cells also recorded simultaneously. 3. Results first show that the latencies to onset of inhibition or to recovery were more frequently similar in neighboring cells than in control cells and that this similarity was enhanced by odor stimulation. Second, the probability that two cells exhibit similar inhibitory periods (i.e., similar latencies to both onset and to recovery) in response to electrical stimulation of LOT, AC, or PC was significantly higher in neighboring than in control cells. Third, only neighboring cells were found to present similar inhibitory periods in response to the stimulation of all of the three structures. 4. Granular activation was also found to modify the temporal patterns of individual mitral cells. However, although these patterns were not systematically modified similarly in neighboring mitral cells, they remained perfectly synchronized with zero delay if they were already synchronous without electrical stimulation. On the contrary, if patterns were spontaneously uncorrelated, electrical stimulation never produced a synchronization of their firings, even if their temporal relationships could be profoundly modified. 5. These results show that neighboring mitral cells can receive granular-induced inhibition with similar latencies and durations with a probability much higher than control cells. Such similarities allow neighboring mitral cells to preserve their temporal correlation despite the powerful inhibitory input from granule cells. Functional hypotheses about the role of the cortical feedback projections onto the bulb are discussed.


1987 ◽  
Vol 63 (5) ◽  
pp. 1757-1762 ◽  
Author(s):  
B. Dureuil ◽  
N. Viires ◽  
Y. Nivoche ◽  
M. Fiks ◽  
R. Pariente ◽  
...  

The effects of halothane administration on diaphragm and tibialis anterior (TA) muscle were investigated in 30 anesthetized mechanically ventilated rats. Diaphragmatic strength was assessed in 17 rats by measuring the abdominal pressure (Pab) generated during supramaximal stimulation of the intramuscular phrenic nerve endings at frequencies of 0.5, 30, and 100 Hz. Halothane was administered during 30 min at a constant minimum alveolar concentration (MAC): 0.5, 1, and 1.5 MAC in three groups of five rats. For each MAC, Pab was significantly reduced for all frequencies of stimulation except at 100 Hz during 0.5 MAC halothane exposure. The effects of halothane (0.5, 1, and 1.5 MAC) on diaphragmatic neuromuscular transmission were assessed in five other rats by measuring the integrated electrical activity of the diaphragm (Edi) during electrical stimulation of the phrenic nerve. No change in Edi was observed during halothane exposure. In five other rats TA contraction was studied by measuring the strength of isometric contraction of the muscle during electrical stimulation of its nerve supply at different frequencies (0.5, 30, and 100 Hz). Muscle function was unchanged during administration of halothane in a cumulative fashion from 0.5 to 1.5 MAC. These results demonstrate that halothane does not affect hindlimb muscle function, whereas it had a direct negative inotropic effect on rat diaphragmatic muscle.


1994 ◽  
Vol 33 (01) ◽  
pp. 129-133 ◽  
Author(s):  
K. Kawahara ◽  
Y. Yamauchi ◽  
K. Niizeki ◽  
T. Yoshioka

Abstract:Interactions are described of central origin between respiratory, cardiac and stepping rhythms during fictive locomotion in paralyzed, vagotomized, and decerebrated cats. Fictive locomotion was induced by tonic electrical stimulation of the mesencephalic locomotor region (MLR). The coherence between heart beat fluctuation, the efferent discharges of the phrenic, and the lateral gastrocnemius nerves was used to evaluate the strength of the coupling between those three rhythms. The heart beat rhythm was modulated by the centrally generated respiratory and stepping rhythms. The central respiratory rhythm was modulated by the centrally generated stepping rhythm. Based on the present findings, we have proposed a new model concerning the functional hierarchical structures of the three biological oscillators.


2001 ◽  
Vol 90 (4) ◽  
pp. 1570-1576 ◽  
Author(s):  
Jalal M. Abu-Shaweesh ◽  
Ismail A. Dreshaj ◽  
Musa A. Haxhiu ◽  
Richard J. Martin

Stimulation of the superior laryngeal nerve (SLN) results in apnea in animals of different species, the mechanism of which is not known. We studied the effect of the GABAA receptor blocker bicuculline, given intravenously and intracisternally, on apnea induced by SLN stimulation. Eighteen 5- to 10-day-old piglets were studied: bicuculline was administered intravenously to nine animals and intracisternally to nine animals. The animals were anesthetized and then decerebrated, vagotomized, ventilated, and paralyzed. The phrenic nerve responses to four levels of electrical SLN stimulation were measured before and after bicuculline. SLN stimulation caused a significant decrease in phrenic nerve amplitude, phrenic nerve frequency, minute phrenic activity, and inspiratory time ( P < 0.01) that was proportional to the level of electrical stimulation. Increased levels of stimulation were more likely to induce apnea during stimulation that often persisted beyond cessation of the stimulus. Bicuculline, administered intravenously or intracisternally, decreased the SLN stimulation-induced decrease in phrenic nerve amplitude, minute phrenic activity, and phrenic nerve frequency ( P < 0.05). Bicuculline also reduced SLN-induced apnea and duration of poststimulation apnea ( P < 0.05). We conclude that centrally mediated GABAergic pathways are involved in laryngeal stimulation-induced apnea.


1988 ◽  
Vol 65 (4) ◽  
pp. 1572-1578 ◽  
Author(s):  
D. F. Speck

Electrical stimulation (50-150 microA, 0.5-ms duration, 3-300 Hz) was performed within three different regions (lateral, ventrolateral, and ventral) of the C2-C3 spinal cord of decerebrate, vagotomized, paralyzed, and artificially ventilated cats. Spinal cord stimulation sites were located by inserting monopolar or bipolar stimulating electrodes either at the dorsolateral sulcus or at least 1 mm medial or lateral to the sulcus. With stimulation at each site, alterations in respiratory rhythm, orthodromic phrenic nerve responses, and antidromic activation of medullary respiratory-modulated neurons were examined. Phrenic nerve responses to cervical spinal cord stimulation consisted of an early excitation (2-4 ms) and/or a late excitation (4-8 ms). Stimulation of the lateral region evoked the greatest amplitude early response and stimulation of the ventrolateral region produced the greatest late excitation. All three stimulus sites elicited antidromic activation of some respiratory-modulated neurons in the dorsal (DRG) and ventral respiratory groups (VRG). The lateral region was the least effective resetting site, and it had the highest incidence of antidromic activation of both DRG and VRG neurons. The ventrolateral region of the cervical spinal cord was the most effective resetting site, but it had the lowest incidence of antidromic activation of DRG respiratory-modulated neurons. In addition, resetting responses were observed with spinal cord stimulation at similar sites in the thoracic and lumbar spinal cord regions thought to be devoid of inspiratory bulbospinal axons.(ABSTRACT TRUNCATED AT 250 WORDS)


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