The primary hypothesis of this study was that the cough motor pattern is produced, at least in part, by medullary respiratory neuronal network response to inputs from “cough” and pulmonary stretch receptor relay neurons nucleus tractus solitarii. Computer simulations a distributed model with proposed connections solitarii ventrolateral produced coughlike inspiratory expiratory patterns. Predicted responses various “types” (I-DRIVER, I-AUG, I-DEC, E-AUG, E-DEC) derived were tested vivo....

1 This study tested predictions from a network model of ventrolateral medullary respiratory neurone interactions for the generation cough motor pattern observed in inspiratory and expiratory pump muscles. 2 Data were 34 mid-collicularly decerebrated, paralysed, artificially ventilated cats. Cough-like patterns (fictive cough) efferent phrenic lumbar nerve activities elicited by mechanical stimulation intrathoracic trachea. Neurones ventral group, including Bötzinger pre-Bötzinger complexes,...

A large body of data suggests that the pontine respiratory group (PRG) is involved in phase-switching and reconfiguration brain stem network. However, connectivity between PRG ventral column (VRC) computational models has been largely ad hoc. We developed a network model with PRG-VRC inferred from coordinated vivo experiments. Neurons were modeled “integrate-and-fire” style; some neurons had pacemaker properties derived Breen et al. recapitulated earlier modeling results, including...

This study addressed the hypothesis that ventrolateral medullary respiratory neurones participate in control of laryngeal motoneurones during both eupnoea and coughing. Data were obtained from 28 mid‐collicular decerebrated, artificially ventilated cats. Cough‐like motor patterns (fictive cough) phrenic, lumbar recurrent nerves elicited by mechanical stimulation intrathoracic trachea. Microelectrode arrays used to monitor simultaneously several ventral group, including Bötzinger...

Data were obtained from 45 anesthetized (Dial), paralyzed, artificially ventilated, bilaterally vagotomized cats. Arrays of extracellular electrodes used to monitor simultaneously the activities lateral medullary respiratory neurons located in rostral and caudal regions ventral group. The average discharge rate as a function time cycle was determined for each neuron concurrent phrenic nerve activity. Most cells tested axonal projections spinal cord or ipsilateral vagus using antidromic...

Current models propose that a neuronal network in the ventrolateral medulla generates basic respiratory rhythm and this column (VRC) is profoundly influenced by neurons of pontine group (PRG). However, functional connectivity among PRG VRC poorly understood. This study addressed four model-based hypotheses: 1) modulation neuron populations reflects paucisynaptic actions multiple populations; 2) connections shape coordinate their respiratory-modulated activities; 3) acts on populations,...

Arrays of extracellular electrodes were used to monitor simultaneously several (2-8) respiratory neurons in the lateral medulla anesthetized, paralyzed, bilaterally vagotomized, artificially ventilated cats. Efferent phrenic nerve activity was also recorded. The average discharge rate as a function time cycle determined for each neuron. Most cells tested spinal or vagal axonal projections using antidromic stimulation methods. Cross-correlational methods analyze spike trains 480 cell pairs....

The morphology and distribution of axon terminals on central column marginal neurons the cat medial superior olivary nucleus (MSO) were analyzed by electron microscopy. Individual or groups cells oriented such that substantial lengths their dendrites within a 5-7 mu thich section selected for detailed study. Thin sections cut from remounted thick sections. Boutons with spherical vesicles arise directly myelinated axons; more than one synaptic region an axon, each separated segment, may...

Lesioning studies have demonstrated that the respiratory rhythm is generated within brain stem and connections between pons medulla must be intact for generation of eupneic breathing in decerebrate or anesthetized vagotomized cat. However, nature proposed functional pontine medullary neurons not well understood. The possibility interactions rostral (n. parabrachialis medialis, Kolliker-Fuse nucleus) ipsilateral ventral group (VRG; n. retroambigualis, ambiguus, retrofacial was investigated...

1. Stimulation of either peripheral chemoreceptors or nucleus raphe obscurus results in long‐term facilitation phrenic motoneurone activity. The first objective this work was to measure the concurrent responses neurones obscurus, tractus solitarii, and regions retrofacial nucleus, ambiguus retroambigualis during induction facilitation. A second goal assess functional relationships chemoresponsive with other monitored locations motoneurones. 2. Up thirty single medullary nerve efferent...

Perturbations of arterial blood pressure change medullary raphe neurone activity and the respiratory motor pattern. This study sought evidence for actions baroresponsive neurones on network. Blood was perturbed by intravenous injection an α 1 ‐adrenergic receptor agonist, unilateral changes in carotid sinus, or occlusion descending aorta thirty‐six Dial‐urethane‐anaesthetized, vagotomized, paralysed, artificially ventilated cats. Neurones were monitored with microelectrode arrays two three...

Lindsey, B. G., K. F. Morris, R. Shannon, and G. L. Gerstein. Repeated patterns of distributed synchrony in neuronal assemblies. J. Neurophysiol. 78: 1714–1719, 1997. Models brain function predict that the recurrence a process or state will be reflected repeated correlated activity. Previous work on medullary raphe assembly dynamics revealed transient changes inimpulse synchrony. This study tested hypothesis these variations include nonrandom association. Spike trains were recorded...

1. Considerable evidence indicates that neurons in the brain stem midline and ventrolateral medulla participate control of breathing. This work was undertaken to detect evaluate for functional links coordinate parallel operations distributed these two domains. 2. Data were from 51 Dial-urethan-anesthetized, bilaterally vagotomized, paralyzed, artificially ventilated cats. Planar arrays tungsten microelectrodes used monitor simultaneously spike trains or three following regions: n. raphe...

1. Recent evidence supports the idea that neurons distributed along midline of brain stem contribute to regulation breathing. This study sought for functional connections between with respiratory-modulated firing rates. 2. Experiments were conducted on 38 anesthetized, paralyzed, bilaterally vagotomized, artificially ventilated cats. Planar arrays tungsten microelectrodes used monitor spike trains two or more simultaneously in regions n. raphe obscurus, pallidus, and magnus. Efferent phrenic...

We tested the hypothesis, motivated in part by a coordinated computational cough network model, that alterations of mean systemic arterial blood pressure (BP) influence excitability and motor pattern cough. Model simulations predicted suppression coughing stimulation baroreceptors. In vivo experiments were conducted on anesthetized spontaneously breathing cats. Cough was elicited mechanical intrathoracic airways. Electromyograms (EMG) inspiratory parasternal, expiratory abdominal, laryngeal...

1. Long-term facilitation is a respiratory memory expressed as an increase in motor output lasting more than hour. This change induced by repeated hypoxia, stimulation of carotid chemoreceptors, or electrical the sinus nerve brainstem mid-line. The present work addressed hypothesis that persistent changes medullary neural networks contribute to long-term facilitation. 2. Carotid chemoreceptors were stimulated close arterial injection CO(2)-saturated saline solution. Phrenic efferent activity...

1. This study addressed the hypothesis that there is a parallel processing of input from carotid chemoreceptors to brainstem neurones involved in inspiratory phase timing and control motor output amplitude. Data were fifteen anaesthetized, bilaterally vagotomized, paralysed, artificially ventilated cats. Carotid stimulated by close arterial injection 200 microliters CO2‐saturated saline solution. 2. Planar arrays tungsten microelectrodes used monitor simultaneously up twenty‐two nucleus...