Effect of thiamylal on discharge of brain stem respiratory neurons during the respiratory phase transition

Our purpose was to compare further eupneic ventilatory activity with that of gasping. Decerebrate, paralyzed, and ventilated cats were used; the vagi were sectioned within the thorax caudal to the laryngeal branches. Activities of the phrenic nerve and medullary respiratory neurons were recorded. Antidromic invasion was used to define bulbospinal, laryngeal, or not antidromically activated units. The ventilatory pattern was reversibly altered to gasping by exposure to 1% carbon monoxide in air. In eupnea, activities of inspiratory neurons commenced at various times during inspiration, and for most the discharge frequency gradually increased. In gasping, the peak discharge frequency of inspiratory neurons was unaltered. However, all commenced activities at the start of the phrenic burst and reached peak discharge almost immediately. The discharge frequencies of all groups of expiratory neurons fell in gasping, with many neurons ceasing activity entirely. These data are consistent with the hypothesis that brain stem mechanisms controlling eupnea and gasping differ fundamentally.

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Effect of morphine on breath-to-breath fluctuation of intra-cycle discharge pattern of brain stem respiratory neurons in rabbits.

The Japanese Journal of Pharmacology ◽

10.1016/s0021-5198(19)50455-3 ◽

1994 ◽

Vol 64 ◽

pp. 205

Author(s):

Yoko Tsukamoto ◽

Fusao Kato ◽

Kazuo Takano ◽

Naofumi Kimura ◽

Takehiko Hukuhara

Keyword(s):

Brain Stem ◽

Respiratory Neurons ◽

Discharge Pattern

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FUNCTIONAL ORGANIZATION OF BRAIN STEM RESPIRATORY NEURONS

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.1963.tb13488.x ◽

2006 ◽

Vol 109 (2) ◽

pp. 571-585 ◽

Cited By ~ 30

Author(s):

G. C. Salmoiraghi

Keyword(s):

Brain Stem ◽

Functional Organization ◽

Respiratory Neurons

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Dynamic reconfiguration of brain stem neural assemblies: respiratory phase-dependent synchrony versus modulation of firing rates

Journal of Neurophysiology ◽

10.1152/jn.1992.67.4.923 ◽

1992 ◽

Vol 67 (4) ◽

pp. 923-930 ◽

Cited By ~ 43

Author(s):

B. G. Lindsey ◽

Y. M. Hernandez ◽

K. F. Morris ◽

R. Shannon ◽

G. L. Gerstein

Keyword(s):

Brain Stem ◽

Temporal Variations ◽

Data Sets ◽

Firing Rates ◽

Neural Assemblies ◽

Cross Correlation Analysis ◽

Respiratory Phase ◽

Sequential Samples ◽

Spike Train Data ◽

Respiratory Phases

1. The objective of this work was to determine whether configurations of midline brain stem neural assemblies change during the respiratory cycle. 2. Spike trains of several single neurons were recorded simultaneously in anesthetized, paralyzed, bilaterally vagotomized, artificially ventilated cats. Data were analyzed with cross-correlational and gravity methods. 3. Sequential samples from each of eight groups of neurons known to contain synchronously discharging neurons exhibited temporal variations in that synchrony. 4. Gravity analysis of short (less than 200-s) samples of spike train data revealed 20 pairs of clustered particles that were not predicted from cross-correlation analysis of the parent data sets (greater than 20 min). 5. Twenty-nine groups of three to eight simultaneously monitored neurons, each with at least two synchronously discharging neurons, were analyzed for evidence of respiratory phase-dependent modulation of that coordinated activity. Spikes from successive interleaved inspiratory and expiratory intervals were analyzed separately. 6. Neurons pairs in 11 groups were more synchronous during the inspiratory interval; six groups had pairs that were more synchronous during the expiratory period. In two groups, different pairs were synchronous in different respiratory phases. In 11 of the 26 pairs that exhibited phase-dependent differences in synchrony, neither neuron had a respiratory-modulated firing rate as judged by either the cycle-triggered histogram or an analysis of variance of their firing rates. 7. Configurations of respiratory-related brain stem neural networks changed with time and the phases of breathing. Neurons with no apparent respiratory modulation of their individual firing rates collectively exhibited respiratory phase-dependent modulation of their impulse synchrony.(ABSTRACT TRUNCATED AT 250 WORDS)

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Transcription factors and the genetic organization of brain stem respiratory neurons

Journal of Applied Physiology ◽

10.1152/japplphysiol.01383.2007 ◽

2008 ◽

Vol 104 (5) ◽

pp. 1513-1521 ◽

Cited By ~ 60

Author(s):

Paul A. Gray

Keyword(s):

Transcription Factor ◽

Transcription Factors ◽

Brain Stem ◽

Respiratory Neurons ◽

Genetic Organization ◽

Parabrachial Nuclei ◽

Genetically Determined ◽

Transcription Factor Expression ◽

The Brain ◽

Anterior Posterior

Breathing is a genetically determined behavior generated by neurons in the brain stem. Transcription factors, in part, determine the basic developmental identity of neurons, but the relationships between these genes and the neural populations generating and modulating respiration are unclear. The diversity of brain stem populations has been proposed to result from a combinatorial code of transcription factor expression corresponding to the anterior-posterior (A-P) and dorsal-ventral (D-V) location of a neuron's birth. I provide a schematic of transcription factor coding identifying at least 15 genetically distinct D-V subdivisions of brain stem neurons that, combined with A-P patterning, may provide a genetic organization of the brain stem in general, with the eventual goal of describing respiratory populations in particular. Using a combination of fate mapping in transgenic mouse lines and immunohistochemistry, we confirm the parabrachial nuclei are derived from a subset of Atoh1 expression progenitor neurons. I hypothesize the Kölliker-Fuse nucleus can be uniquely defined in the neonate mouse by the coexpression of the transcription factor FoxP2 in Atoh1-derived neurons of rhombomere 1.

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Functional organization of respiratory neurons in the central respiratory mechanisms in brain stem and drug action thereon.

The Japanese Journal of Pharmacology ◽

10.1016/s0021-5198(19)63296-8 ◽

1985 ◽

Vol 39 ◽

pp. 59

Author(s):

Takehiko Hukuhara

Keyword(s):

Brain Stem ◽

Functional Organization ◽

Drug Action ◽

Respiratory Neurons

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Pontine respiratory activity involved in inspiratory/expiratory phase transition

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2009.0074 ◽

2009 ◽

Vol 364 (1529) ◽

pp. 2517-2526 ◽

Cited By ~ 67

Author(s):

Michael Mörschel ◽

Mathias Dutschmann

Keyword(s):

Phase Transition ◽

Sensory Feedback ◽

Respiratory Pattern ◽

Respiratory Neurons ◽

Related Activity ◽

Lung Inflation ◽

Pulmonary Stretch Receptors

Control of the timing of the inspiratory/expiratory (IE) phase transition is a hallmark of respiratory pattern formation. In principle, sensory feedback from pulmonary stretch receptors (Breuer–Hering reflex, BHR) is seen as the major controller for the IE phase transition, while pontine-based control of IE phase transition by both the pontine Kölliker–Fuse nucleus (KF) and parabrachial complex is seen as a secondary or backup mechanism. However, previous studies have shown that the BHR can habituate in vivo . Thus, habituation reduces sensory feedback, so the role of the pons, and specifically the KF, for IE phase transition may increase dramatically. Pontine-mediated control of the IE phase transition is not completely understood. In the present review, we discuss existing models for ponto-medullary interaction that may be involved in the control of inspiratory duration and IE transition. We also present intracellular recordings of pontine respiratory units derived from an in situ intra-arterially perfused brainstem preparation of rats. With the absence of lung inflation, this preparation generates a normal respiratory pattern and many of the recorded pontine units demonstrated phasic respiratory-related activity. The analysis of changes in membrane potentials of pontine respiratory neurons has allowed us to propose a number of pontine-medullary interactions not considered before. The involvement of these putative interactions in pontine-mediated control of IE phase transitions is discussed.

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