Electrophysiological demonstration of the projection from expiratory neurones in rostral medulla to contralateral dorsal respiratory group

Lipski, Janusz; Merrill, E. G.

doi:10.1016/0006-8993(80)91140-3

Cited by 122 publications

(29 citation statements)

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“…14C of Cohen (1979); step-ramp patterns are shown in Fig. 2 of Lipski & Merrill (1980) and in Fig. 3 of Feldman & Cohen (1978).…”

Section: Spontaneous Discharge Patternsmentioning

confidence: 99%

“…However, a number of authors have recorded the discharges of expiratory motoneurones or expiratory muscles (internal intercostal or abdominal) (Sears, 1964a, b; Bainton, Ledlie, Pack & Fishman, 1983;Arita & Bishop, 1983). Of the many studies of respiratory neurone activity in the medulla, only some have paid special attention to expiratory neurones (Koepchen, Kliissendorf & Philipp, 1973;Feldman & Cohen, 1978; Sommer, 1978;Bainton & Kirkwood, 1979; Koepchen, Sommer, Frank, Kliissendorf, Kriimer, Rosin & Forstreuter, 1979;Lipski & Merrill, 1980;Merrill, Lipski, Kubin & Fedorko, 1983;Fedorko & Merrill, 1984).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Caudal medullary expiratory neurone and internal intercostal nerve discharges in the cat: effects of lung inflation.

Cohen¹,

Feldman²,

Sommer³

1985

The Journal of Physiology

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SUMMARY1. In midcollicular decerebrate, thoracotomized, paralysed cats that were ventilated by a cycle-triggered pump and had an expiratory load, recordings were taken from expiratory neurones in the nucleus retroambigualis of the caudal medulla and from the internal intercostal nerves at T8-T9 levels.2. Expiratory neurone and internal intercostal activities had augmenting patterns of two types: (a) step-ramp (one-third of the neurones): a large initial increase of activity synchronous with inspiratory termination, followed by a ramp increase throughout the expiratory phase; (b) ramp (two-thirds of the neurones): a steady rise of activity without a sharp initial increase, discharge usually starting after a delay (as much as several hundred milliseconds) from the onset of expiration. Both types of unit pattern could occur together with each type of internal intercostal pattern. At the end of expiration, unit activity shut off abruptly just prior (0-120 ms) to the onset of phrenic discharge. 3. The effects of pulmonary afferent discharge on unit and internal intercostal activities were evaluated by use of inflation tests: (a) withholding inflation during the preceding inspiratory phase; (b) maintaining inflation at the end-inspiratory level during expiration. Both tests produced lengthening of expiratory phase duration (TE), but their effects on activity differed. (a) Following no-inflation during inspiration, the discharge onset delay was lengthened for most ramp neurones, but for only a minority of step-ramp neurones; the slope of activity augmentation did not change on the average; and the peak (end-expiratory) discharge frequency was only slightly increased. (b) The predominant effect of maintained expiratory inflation was reduction of activity slope for ramp neurones and for a minority of step-ramp neurones, as well as increase of peak frequency; there was a moderate increase of discharge onset delay for ramp neurones, but not for step-ramp neurones.4 M. I. COHEN, J. L. FELDMAN AND D. SOMMERassociated with lengthening of the durations of both the discharge onset delay and the discharge burst, but there was no correlation between changes of these two variables.5. We observed a 'reversal phenomenon': moderate inflation facilitated activity, whereas higher inflation levels depressed activity, as demonstrated by: (a) comparison of effects of maintained expiratory deflation (removal of the expiratory load) and of maintained expiratory inflation, both of which reduced activity; (b) comparison of effects of phasic expiratory inflations having different magnitudes.6. The existence of a 'mobilization time' for production of the expiratoryinspiratory phase-switch is suggested by the observation that when maintained expiratory inflation was terminated before the onset of inspiration, there was usually a delay of several hundred milliseconds between the end of inflation and the onset of inspiration.7. Monosynaptic excitation of internal intercostal motoneurones by medullary expiratory neurones was indicated by cross-cor...

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“…14C of Cohen (1979); step-ramp patterns are shown in Fig. 2 of Lipski & Merrill (1980) and in Fig. 3 of Feldman & Cohen (1978).…”

Section: Spontaneous Discharge Patternsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Caudal medullary expiratory neurone and internal intercostal nerve discharges in the cat: effects of lung inflation.

Cohen¹,

Feldman²,

Sommer³

1985

The Journal of Physiology

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“…Neurons within the VRG can be divided into 2 populations based on their impulse discharge pattern. Neurons that produce bursts of action potentials synchronous with the phrenic nerve discharge (inspiratory neurons) are concentrated between the obex and most rostra1 portion of the VRG--the BGtzinger complex (Kalia et al, 1979;Lipski and Merrill, 1980;Merrill and Fedorko, 1984). Neurons that produce bursts of impulse activity during the periods of phrenic nerve silence (expiratory neurons) are located between the obex and the upper cervical spinal cord and in the B&zinger complex.…”

mentioning

confidence: 99%

Respiratory motoneuronal activity is altered by injections of picomoles of glutamate into cat brain stem

McCrimmon¹,

Feldman²,

Speck³

1986

J. Neurosci.

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The local neural circuitry underlying the control of breathing was studied by injecting nanoliter volumes of excitatory amino acids into discrete regions of cat brain stem. Experiments were performed on chloralose-urethane anesthetized, vagotomized, paralyzed, and artificially ventilated cats. Phrenic, intercostal, and recurrent laryngeal nerve discharges were recorded. Multibarrel pipettes were used for recording and pressure ejection of drugs or a dye for marking recording and ejection sites. Ejected volumes were directly monitored for every injection. Injections, proximal to neurons discharging with a respiratory periodicity, of as little of 200 fmol of L-glutamate in 200 pl of saline elicited marked, site-specific increases or decreases in respiratory motoneuronal discharge. N-Methyl-D-aspartic acid and homocysteic acid elicited similar site-specific alterations in respiratory motor output, although some details of the response could differ qualitatively. Responses to all the excitatory agents used were attenuated by concurrent injection of kynurenic acid, DL-2-aminoA-phosphonobutyric acid, or glutamic acid diethyl ester. There was no change in spontaneous phrenic nerve discharge in response to injections of equivalent or larger volumes of saline or lidocaine. These results indicate a heterogeneity in the spatial organization of the brain-stem neural circuitry underlying respiratory control, which has not been described previously. This injection technique may provide a mechanism for probing the neural circuitry underlying other behaviors.Brain function underlying behavior in mammals involves information transfer between neurons in complex networks. The nuclear and layered structure of the mammalian brain suggests that small aggregates of neurons act as functional units. It is of fundamental interest to determine the nature of this local information transfer and its consequences in terms of behavior. In this paper, we present an approach to study this problem using site-specific delivery of (sub)picomolar amounts of excitatory amino acids in nanoliter volumes. Using this approach, we present evidence of a neuronal mosaic underlying the control of breathing.Neurons that discharge with a respiratory periodicity are concentrated in the nucleus ambiguus-retroambigualis (ventral respiratory group, VRG) and the nucleus tractus solitarius of the medulla (Cohen, 1979; Feldman, in press;von Euler, 1983). Received Oct. 24, 1985; revised Jan. 21, 1986; accepted Jan. 22, 1986. The technical assistnce of Paul G. Bums and the helpful comments of Professor Oscar Hechter are gratefully acknowledged. We would like to thank Drs. Howard H. Ellenberger, Debra E. Weese-Mayer, and Jeffery C. Smith for their help in experiments at the latter stages of this study. This work was supported by NIH Grant NS-21036.Correspondence should be addressed to Jack L. The VRG extends rostrally from the spinomedullary junction to the level of the retrofacial nucleus. Neurons within the VRG can be divided into 2 populations based on their impuls...

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“…The ventral group consists of inspiratory and expiratory neurones lying in a region associated with the nucleus paraambiguus and retroambigalis in the vicinity of the nucleus ambiguus and having bulbospinal or propriobulbar axons (Batsel, 1964;Merrill, 1970;Bianchi, 1971). Recently, a third group of respiratory neurones, at the rostral extension of the ventral respiratory group, has been identified by neuroanatomical (Kalia, Feldman & Cohen, 1979 ;Bystrzycka, 1980) and electrophysiological (Lipski & Merrill, 1980;Bianchi & Barillot, 1982;Fedorko & Merrill, 1984) studies. This group includes the so-called 'B6tzinger complex' which consists primarily of expiratory neurones (Lipski & Merrill, 1980) and the retrofacial group, including respiratory neurones of both the 'Botzinger complex' and the retrofacial nucleus (Bianchi & Barillot, 1982;Bianchi, 1985).…”

mentioning

confidence: 99%

“…In addition, other types of respiratory neurones exist in the region of the retrofacial nucleus. These include early burst inspiratory and early expiratory (postinspiratory) neurones with decrementing discharge patterns, inspiratory neurones with augmenting discharge patterns, and phase-spanning neurones (Lipski & Merrill, 1980;Bianchi & Barillot, 1982;Bianchi, 1985;Remmers, Takeda, Schultz & Haji, 1985b). Some of these may be motoneurones of upper-airway muscles, the cell bodies of which lie in the rostral part of the nucleus ambiguus or in the retrofacial nucleus itself.…”

mentioning

confidence: 99%

Electrophysiological properties of rostral medullary respiratory neurones in the cat: an intracellular study.

Bianchi¹,

Grélot²,

Iscoe³

et al. 1988

The Journal of Physiology

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SUMMARY1. We recorded the membrane potentials of sixty-three respiratory neurones in the rostral, ventral medulla of decerebrate vagotomized cats. Stable recordings were obtained in thirty-eight expiratory and twenty-five inspiratory neurones. Axonal projections were identified by antidromic invasion after electrical stimulation of the region of the dorsal respiratory group (DRG), spinal cord, and the cervical vagus, superior laryngeal and pharyngeal nerves.2. Two types of expiratory neurones were encountered: those in which the membrane potential progressively depolarized (augmenting neurones, n = 22) and those in which the membrane potential repolarized (decrementing or post-inspiratory neurones, n = 16) during the interval between phrenic bursts. Both types were hyperpolarized during inspiration by chloride-dependent, inhibitory postsynaptic potentials (IPSPs) which decreased membrane resistance. In augmenting neurones two waves of IPSPs appeared, one early and one late in inspiration.3. Five out of seventeen augmenting expiratory neurones tested were antidromically activated by contralateral stimulation of the spinal cord (n = 3) or the DRG (n = 2). Spinal axons were not detected in any of the sixteen decrementing expiratory neurones tested. Of thirteen expiratory neurones tested with pharyngeal nerve stimulation, one (an augmenting type) was antidromically activated. Superior laryngeal or vagal axons could not be demonstrated for any expiratory neurones.4. Two types of inspiratory neurones were also encountered: those displaying progressive depolarization throughout inspiration (n = 5) and those which gradually repolarized after maximal depolarization at the onset of inspiration (n = 10). None of the former had identifiable spinal or medullary axons, but superior laryngeal axons were demonstrated in three and pharyngeal axons were found in three. None of the latter was antidromically activated from any of the sites stimulated.5. Stimulation of the superior laryngeal or pharyngeal nerves evoked excitatory postsynaptic potentials (EPSPs) in all neurones except in post-inspiratory neurones.

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Electrophysiological demonstration of the projection from expiratory neurones in rostral medulla to contralateral dorsal respiratory group

Cited by 122 publications

References 8 publications

Caudal medullary expiratory neurone and internal intercostal nerve discharges in the cat: effects of lung inflation.

Caudal medullary expiratory neurone and internal intercostal nerve discharges in the cat: effects of lung inflation.

Respiratory motoneuronal activity is altered by injections of picomoles of glutamate into cat brain stem

Electrophysiological properties of rostral medullary respiratory neurones in the cat: an intracellular study.

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