Reconfiguration of the Respiratory Network at the Onset of Locust Flight

1998 ◽  
Vol 80 (6) ◽  
pp. 3137-3147 ◽  
Author(s):  
Jan-Marino Ramirez
Keyword(s):  
Respiratory Activity ◽  
Respiratory Rhythm ◽  
Quiescent State ◽  
Suboesophageal Ganglion ◽  
Rhythm Generator ◽  
Locust Flight ◽  
Respiratory Network ◽  
Intracellular Stimulation ◽  
Tonic Stimulation ◽  
Stimulation Of

Ramirez, Jan-Marino. Reconfiguration of the respiratory network at the onset of locust flight. J. Neurophysiol. 80: 3137–3147, 1998. The respiratory interneurons 377, 378, 379 and 576 were identified within the suboesophageal ganglion (SOG) of the locust. Intracellular stimulation of these neurons excited the auxillary muscle 59 (M59), a muscle that is involved in the control of thoracic pumping in the locust. Like M59, these interneurons did not discharge during each respiratory cycle. However, the SOG interneurons were part of the respiratory rhythm generator because brief intracellular stimulation of these interneurons reset the respiratory rhythm and tonic stimulation increased the frequency of respiratory activity. At the onset of flight, the respiratory input into M59 and the SOG interneurons was suppressed, and these neurons discharged in phase with wing depression while abdominal pumping movements remained rhythmically active in phase with the slower respiratory rhythm (Fig. 9 ). The suppression of the respiratory input during flight seems to be mediated by the SOG interneuron 388. This interneuron was tonically activated during flight, and intracellular current injection suppressed the respiratory rhythmic input into M59. We conclude that the respiratory rhythm generator is reconfigured at flight onset. As part of the rhythm-generating network, the interneurons in the SOG are uncoupled from the rest of the respiratory network and discharge in phase with the flight rhythm. Because these SOG interneurons have a strong influence on thoracic pumping, we propose that this neural reconfiguration leads to a behavioral reconfiguration. In the quiescent state, thoracic pumping is coupled to the abdominal pumping movements and has auxillary functions. During flight, thoracic pumping is coupled to the flight rhythm and provides the major ventilatory movements during this energy-demanding locomotor behavior.

scholarly journals Maturation of the Mammalian Respiratory System

1999 ◽  
Vol 79 (2) ◽  
pp. 325-360 ◽  
Author(s):  
Gérard Hilaire ◽  
Bernard Duron
Keyword(s):  
Respiratory Activity ◽  
Respiratory Rhythm ◽  
Ventrolateral Medulla ◽  
Pacemaker Neurons ◽  
Inhibitory Processes ◽  
Respiratory Rhythmogenesis ◽  
Respiratory Network ◽  
Network Functions

In this review, the maturational changes occurring in the mammalian respiratory network from fetal to adult ages are analyzed. Most of the data presented were obtained on rodents using in vitro approaches. In gestational day 18 (E18) fetuses, this network functions but is not yet able to sustain a stable respiratory activity, and most of the neonatal modulatory processes are not yet efficient. Respiratory motoneurons undergo relatively little cell death, and even if not yet fully mature at E18, they are capable of firing sustained bursts of potentials. Endogenous serotonin exerts a potent facilitation on the network and appears to be necessary for the respiratory rhythm to be expressed. In E20 fetuses and neonates, the respiratory activity has become quite stable. Inhibitory processes are not yet necessary for respiratory rhythmogenesis, and the rostral ventrolateral medulla (RVLM) contains inspiratory bursting pacemaker neurons that seem to constitute the kernel of the network. The activity of the network depends on CO2 and pH levels, via cholinergic relays, as well as being modulated at both the RVLM and motoneuronal levels by endogenous serotonin, substance P, and catecholamine mechanisms. In adults, the inhibitory processes become more important, but the RVLM is still a crucial area. The neonatal modulatory processes are likely to continue during adulthood, but they are difficult to investigate in vivo. In conclusion, 1) serotonin, which greatly facilitates the activity of the respiratory network at all developmental ages, may at least partly define its maturation; 2) the RVLM bursting pacemaker neurons may be the kernel of the network from E20 to adulthood, but their existence and their role in vivo need to be further confirmed in both neonatal and adult mammals.

scholarly journals Distribution of Intersegmental Interneurones That Can Reset the Respiratory Rhythm of the Locust

1989 ◽  
Vol 141 (1) ◽  
pp. 151-176 ◽  
Author(s):  
J. M. RAMIREZ ◽  
K.G. PEARSON
Keyword(s):  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Rate Increase ◽  
Respiratory Rhythm ◽  
Abdominal Ganglion ◽  
Suboesophageal Ganglion ◽  
Active Components ◽  
Rhythm Generator ◽  
Metathoracic Ganglion ◽  
Staining Techniques

Interneurones in the respiratory rhythm generator of the locust were identified by means of intracellular recording and staining techniques. A description is made of the properties and structures of nine intersegmental neurones which reset the respiratory rhythm when injected with current pulses. All but one of these neurones discharged in phase with expiration. The injection of constant depolarizing current into these interneurones altered the respiratory rate (increase for six, decrease for three). The respiratory rhythm generator extends more posteriorly within the ventral nerve cord than the metathoracic ganglion. In the first fused abdominal ganglion, four individual interneurones were identified descending into the unfused abdominal ganglia. In the first unfused abdominal ganglion an intemeurone which reset the respiratory rhythm was found ascending into the metathoracic ganglion. The respiratory rhythm generator also extends more anteriorly within the ventral nerve cord than the metathoracic ganglion. Two interneurones influencing the respiratory rhythm send their axons from the first fused abdominal ganglion into the meta- and mesothoracic ganglia. One of these directly excited a mesothoracic intemeurone which also influenced the respiratory rhythm when injected with current. In the suboesophageal ganglion another intemeurone was found which, although capable of resetting the respiratory rhythm, was not alway active during respiration. We conclude that the respiratory rhythm generator is distributed over abdominal, thoracic and suboesophageal ganglia. At least one part of the respiratory rhythm generator (in the suboesophageal ganglion) is not always active and can be recruited during vigorous respiration. Thus the number of active components in the respiratory rhythm generator is variable and additional elements can be recruited depending on the behavioural situation.

Control of feeding motor output by paracerebral neurons in brain of Pleurobranchaea californica

1982 ◽  
Vol 47 (5) ◽  
pp. 885-908 ◽  
Author(s):  
R. Gillette ◽  
M. P. Kovac ◽  
W. J. Davis
Keyword(s):  
Feeding Behavior ◽  
Action Potentials ◽  
Tactile Stimulation ◽  
Natural Food ◽  
Buccal Ganglion ◽  
Pleurobranchaea Californica ◽  
Feeding Rhythm ◽  
Intracellular Stimulation ◽  
Motor Rhythm ◽  
Stimulation Of

1. A population of interneurons that control feeding behavior in the mollusk Pleurobranchaea has been analyzed by dye injection and intracellular stimulation/recording in whole animals and reduced preparations. The population consists of 12-16 somata distributed in two bilaterally symmetrical groups on the anterior edge of the cerebropleural ganglion (brain). On the basis of their position adjacent to the cerebral lobes, these cells have been named paracerebral neurons (PCNs). This study concerns pme subset pf [MCs. the large, phasic ones, which have the strongest effect on the feeding rhythm (21). 2. Each PCN sends a descending axon via the ipsilateral cerebrobuccal connective to the buccal ganglion. Axon branches have not been detected in other brain or buccal nerves and hence the PCNs appear to be interneurons. 3. In whole-animal preparations, tonic intracellular depolarization of the PNCs causes them to discharge cyclic bursts of action potentials interrupted by a characteristic hyperpolarization. In all specimens that exhibit feeding behavior, the interburst hyperpolarization is invariably accompanied by radula closure and the beginning of proboscis retraction (the "bite"). No other behavorial effect of PCN stimulation has been observed. 4. In whole-animal preparations, the PCNs are excited by food and tactile stimulation of the oral veil, rhinophores, and tentacles. When such stimuli induce feeding the PCNs discharge in the same bursting pattern seen during tonic PCN depolarization, with the cyclic interburst hyperpolarization phase locked to the bit. When specimens egest an unpalatable object by cyclic buccal movements, however, the PCNs are silent. The PCNs therefore exhibit properties expected of behaviorally specific "command" neurons for feeding. 5. Silencing one or two PCNs by hyperpolarization may weaken but does not prevent feeding induced by natural food stimuli. Single PCNs therefore can be sufficient but are not necessary to induction of feeding behavior. Instead the PCNs presumably operate as a population to control feeding. 6. In isolated nervous system preparations tonic extracellular stimulation of the stomatogastric nerve of the buccal ganglion elicits a cyclic motor rhythm that is similar in general features to the PNC-induced motor rhythm. Bursts of PCN action potentials intercalated at the normal phase position in this cycle intensify the buccal rhythm. Bursts of PCN impulses intercalated at abnormal phase positions reset the buccal rhythm. The PCNs, therefore, also exhibit properties expected of pattern-generator elements and/or coordinating neurons for the buccal rhythm. 7. The PCNs are recruited into activity when the buccal motor rhythm is elicited by stomatogastric nerve stimulation or stimulation of the reidentifiable ventral white cell. The functional synergy between the PCNs and the buccal rhythm is therefore reciprocal. 8...

The neurophysiology of respiration in decapod crustacea. II. The sensory system

1969 ◽  
Vol 47 (3) ◽  
pp. 435-441 ◽  
Author(s):  
Valerie M. Pasztor
Keyword(s):  
Connective Tissue ◽  
Sensory Input ◽  
Respiratory Rhythm ◽  
Sensory System ◽  
Nerve Fibers ◽  
Rhythm Generator ◽  
Decapod Crustacea ◽  
New Type

The mechanoreceptors of the respiratory appendage were studied by histological and electrophysiological techniques.A new type of mechanoreceptor is described and named the "oval organ". It consists of a specialized oval patch of cuticle 1–2 mm in length which is traversed by a spine or longitudinal thickening. Closely applied to the cuticle is a pad of connective tissue richly supplied with dendrites from two large nerve fibers. The orientation of the spine and the dendrites ensures that the receptor responds preferentially to certain stresses or foldings of the oval organ. It lies at the base of the scaphognathite on the dorsal surface.No internal proprioceptors were observed. Movements of the appendage are signalled either by the oval organ, epidermal receptors, or hair sensilla.The possible effect of sensory input upon the central respiratory rhythm generator is discussed.

Increased corticospinal excitability prior to arm cycling is due to enhanced supraspinal but not spinal motoneurone excitability

2013 ◽  
Vol 38 (11) ◽  
pp. 1154-1161 ◽  
Author(s):  
Kevin E. Power ◽  
David B. Copithorne
Keyword(s):  
Magnetic Stimulation ◽  
Corticospinal Tract ◽  
Biceps Brachii ◽  
Motor Evoked Potentials ◽  
Corticospinal Excitability ◽  
Quiescent State ◽  
M Wave ◽  
Arm Cycling ◽  
Intention To Move ◽  
Stimulation Of

Human studies have not assessed supraspinal or spinal motoneurone excitability in the quiescent state prior to a rhythmic and alternating cyclical motor output. The purpose of the current study was to determine whether supraspinal and (or) spinal motoneurone excitability was modulated in humans prior to arm cycling when compared with rest with no intention to move. We hypothesized that corticospinal excitability would be enhanced prior to arm cycling due, in part, to increased spinal motoneurone excitability. Supraspinal and spinal motoneurone excitability were assessed via transcranial magnetic stimulation (TMS) of the motor cortex and transmastoid stimulation of the corticospinal tract, respectively. Surface electromyography recordings of TMS motor evoked potentials (MEPs) and cervicomedullary MEPs (CMEPs) were made from the relaxed biceps brachii muscle prior to rhythmic arm cycling and at rest with no intention to move. The amplitude of the MEPs was greater (mean increase: +9.8% of maximal M wave; p = 0.006) and their onset latencies were shorter (mean decrease: –1.5 ms; p < 0.05) prior to cycling when compared with rest. The amplitudes of the CMEPs at any of 3 stimulation intensities were not different between conditions. We conclude that premovement enhancement of corticospinal excitability is greater prior to arm cycling than at rest because of increases in supraspinal but not spinal motoneurone excitability.

Identification of Mechanoafferent Neurons in Terrestrial Snail: Response Properties and Synaptic Connections

2002 ◽  
Vol 87 (5) ◽  
pp. 2364-2371 ◽  
Author(s):  
Aleksey Y. Malyshev ◽  
Pavel M. Balaban
Keyword(s):  
Avoidance Behavior ◽  
Receptive Fields ◽  
Dorsal Surface ◽  
Mechanical Stimulus ◽  
Terrestrial Snail ◽  
Mechanosensory Neurons ◽  
Intracellular Stimulation ◽  
Pleural Ganglion ◽  
Withdrawal Response ◽  
Stimulation Of

In this study, we describe the putative mechanosensory neurons, which are involved in the control of avoidance behavior of the terrestrial snail Helix lucorum. These neurons, which were termed pleural ventrolateral (PlVL) neurons, mediated part of the withdrawal response of the animal via activation of the withdrawal interneurons. Between 15 and 30 pleural mechanosensory neurons were located on the ventrolateral side of each pleural ganglion. Intracellular injection of neurobiotin revealed that all PlVL neurons sent their axons into the skin nerves. The PlVL neurons had no spontaneous spike activity or fast synaptic potentials. In the reduced “CNS-foot” preparations, mechanical stimulation of the skin covering the dorsal surface of the foot elicited spikes in the PlVL neurons without any noticeable prepotential activity. Mechanical stimulus-induced action potentials in these cells persisted in the presence of high-Mg2+/zero-Ca2+ saline. Each neuron had oval-shaped receptive field 5–20 mm in length located on the dorsal surface of the foot. Partial overlapping of the receptive fields of different neurons was observed. Intracellular stimulation of the PlVL neurons produced excitatory inputs to the parietal and pleural withdrawal interneurons, which are known to control avoidance behavior. The excitatory postsynaptic potentials (EPSPs) in the withdrawal interneurons were induced in 1:1 ratio to the PlVL neuron spikes, and spike-EPSP latency was short and highly stable. These EPSPs also persisted in the high-Mg2+/high-Ca2+ saline, suggesting monosynaptic connections. All these data suggest that PlVL cells were the primary mechanosensory neurons.

scholarly journals Multimodal Medullary Neurons and Correlational Linkages of the Respiratory Network

1999 ◽  
Vol 82 (1) ◽  
pp. 188-201 ◽  
Author(s):  
Zhongzeng Li ◽  
Kendall F. Morris ◽  
David M. Baekey ◽  
Roger Shannon ◽  
Bruce G. Lindsey
Keyword(s):  
Firing Rate ◽  
Nucleus Tractus Solitarius ◽  
Motor Pattern ◽  
Sensory Modality ◽  
Spike Trains ◽  
Negative Feedback Regulation ◽  
Firing Rates ◽  
Respiratory Network ◽  
Cross Correlation Analysis ◽  
Stimulation Of

This study addresses the hypothesis that multiple sensory systems, each capable of reflexly altering breathing, jointly influence neurons of the brain stem respiratory network. Carotid chemoreceptors, baroreceptors, and foot pad nociceptors were stimulated sequentially in 33 Dial-urethan–anesthetized or decerebrate vagotomized adult cats. Neuronal impulses were monitored with microelectrode arrays in the rostral and caudal ventral respiratory group (VRG), nucleus tractus solitarius (NTS), and n. raphe obscurus. Efferent phrenic nerve activity was recorded. Spike trains of 889 neurons were analyzed with cycle-triggered histograms and tested for respiratory-modulated firing rates. Responses to stimulus protocols were assessed with peristimulus time and cumulative sum histograms. Cross-correlation analysis was used to test for nonrandom temporal relationships between spike trains. Spike-triggered averages of efferent phrenic activity and antidromic stimulation methods provided evidence for functional associations of bulbar neurons with phrenic motoneurons. Spike train cross-correlograms were calculated for 6,471 pairs of neurons. Significant correlogram features were detected for 425 pairs, including 189 primary central peaks or troughs, 156 offset peaks or troughs, and 80 pairs with multiple peaks and troughs. The results provide evidence that correlational medullary assemblies include neurons with overlapping memberships in groups responsive to different sets of sensory modalities. The data suggest and support several hypotheses concerning cooperative relationships that modulate the respiratory motor pattern. 1) Neurons responsive to a single tested modality promote or limit changes in firing rate of multimodal target neurons. 2) Multimodal neurons contribute to changes in firing rate of neurons responsive to a single tested modality. 3) Multimodal neurons may promote responses during stimulation of one modality and “limit” changes in firing rates during stimulation of another sensory modality. 4) Caudal VRG inspiratory neurons have inhibitory connections that provide negative feedback regulation of inspiratory drive and phase duration.

Organization of rat vibrissa motor cortex and adjacent areas according to cytoarchitectonics, microstimulation, and intracellular stimulation of identified cells

2004 ◽  
Vol 479 (4) ◽  
pp. 360-373 ◽  
Author(s):  
Michael Brecht ◽  
Andreas Krauss ◽  
Sajjad Muhammad ◽  
Laleh Sinai-Esfahani ◽  
Sebastiano Bellanca ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Intracellular Stimulation ◽  
Stimulation Of

scholarly journals Reciprocal connectivity of the periaqueductal gray with the ponto-medullary respiratory network in rat

2020 ◽  
Author(s):  
Pedro Trevizan-Baú ◽  
Werner I. Furuya ◽  
Stuart B. Mazzone ◽  
Davor Stanić ◽  
Rishi R. Dhingra ◽  
...  
Keyword(s):  
Respiratory Rhythm ◽  
Upper Airway ◽  
Periaqueductal Gray ◽  
List Type ◽  
Airway Patency ◽  
Respiratory Network ◽  
Cholera Toxin Subunit B ◽  
Motor Activities ◽  
Descending Projections ◽  
Subunit B

AbstractSynaptic activities of the periaqueductal gray (PAG) can modulate or appropriate the respiratory motor activities in the context of behavior and emotion via descending projections to nucleus retroambiguus. However, alternative anatomical pathways for the mediation of PAG-evoked respiratory modulation via core nuclei of the brainstem respiratory network remains only partially described. We injected the retrograde tracer Cholera toxin subunit B (CT-B) in the pontine Kölliker-Fuse nucleus (KFn, n=5), medullary Bötzinger (BötC, n=3) and pre-Bötzinger complexes (pre-BötC; n=3), and the caudal raphé nuclei (n=3), and quantified the ascending and descending connectivity of the PAG. CT-B injections in the KFn, pre-BötC, and caudal raphé, but not in the BötC, resulted in CT-B-labeled neurons that were predominantly located in the lateral and ventrolateral PAG columns. In turn, CT-B injections into the lateral and ventrolateral PAG columns (n=4) yield the highest numbers of CT-B-labeled neurons in the KFn and far fewer numbers of labeled neurons in the pre-BötC and caudal raphé. Analysis of the relative projection strength revealed that the KFn shares the densest reciprocal connectivity with the PAG (ventrolateral and lateral columns, in particular). Overall, our data imply that the PAG may engage a distributed respiratory rhythm and pattern generating network beyond the nucleus retroambiguus to mediate downstream modulation of breathing. However, the reciprocal connectivity of the KFn and PAG suggests specific roles for synaptic interaction between these two nuclei that are most likely related to the regulation of upper airway patency during vocalization or other volitional orofacial behaviors.HighlightsThe lateral and ventrolateral PAG project to the primary respiratory network.The Kölliker-Fuse nucleus shares the densest reciprocal connectivity with the PAG.The Bötzinger complex appears to have very little connectivity with the PAG.

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