Respiration depends upon brainstem neuronal circuits that produce the respiratory rhythm and relay it, through the ventrolateral columns, to motor neurons in the spinal cord. This brainstem system produces respiration automatically, i.e., without conscious effort, and is responsive to chemical and mechanical stimuli that signal imbalances in respiratory homeostasis. In addition to this automatic/metabolic respiratory system, there is a voluntary/behavioral system that controls the respiratory muscles during speaking, breath holding, and other voluntary respirabory acts. Recent results from our laboratory showed that the voluntary/behavioral system interacts with respiratory cells that are part of the automatic/metabolic system. Cats were trained to halt inspiration abruptly and to prolong the following expiration when a tone sounded. Recordings of brainstem respiratory neurons showed that their activity patterns were analogous to the behavioral respiratory response, indicating there was interaction of the voluntary/behavioral system with the automatic/metabolic system, but these recordings did not show which cells might produce the shortened inspiration and the prolonged expiration. The long-term objective is to discover the neural mechanisms of voluntary/behavioral respiratory responses.
The specific aims are to record and analyze the activity of three groups of respiratory cells, each of which may have a role in either the inhibition of inspiration or the switching of the respiratory cycle from one phase to the other--necessary acts in the performance of the behavioral respiratory response. These three groups are: 1) the expiratory cells in the region of the retrofacial nucleus, 2) the inspiratory cells of the ventrolateral nucleus of tractus solitarius, and 3) the phase-spanning cells of the pontine pneumotaxic center. For these experiments, cats will be trained to stop inspiration and prolong expiration when a tone sounds. Single neurons within the three specified groups will be recorded while the animals perform these responses. Cells mediating the response should be activated during the task. Our goal is to identify the cells that inhibit inspiration and prolong expiration when the animals produce these behavioral responses.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL021257-12
Application #
3336432
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Project Start
1986-07-01
Project End
1989-06-30
Budget Start
1988-07-01
Budget End
1989-06-30
Support Year
12
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Texas Tech University
Department
Type
Schools of Medicine
DUNS #
609980727
City
Lubbock
State
TX
Country
United States
Zip Code
79430
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Dunin-Barkowski, Witali L; Sirota, Mikhail G; Lovering, Andrew T et al. (2006) Precise rhythmicity in activity of neocortical, thalamic and brain stem neurons in behaving cats and rabbits. Behav Brain Res 175:27-42
Lovering, Andrew T; Fraigne, Jimmy J; Dunin-Barkowski, Witali L et al. (2003) Hypocapnia decreases the amount of rapid eye movement sleep in cats. Sleep 26:961-7
Orem, J; Lovering, A T; Dunin-Barkowski, W et al. (2000) Endogenous excitatory drive to the respiratory system in rapid eye movement sleep in cats. J Physiol 527 Pt 2:365-76
Orem, J; Vidruk, E H (1998) Activity of medullary respiratory neurons during ventilator-induced apnea in sleep and wakefulness. J Appl Physiol 84:922-32
Orem, J (1998) Augmenting expiratory neuronal activity in sleep and wakefulness and in relation to duration of expiration. J Appl Physiol 85:1260-6
Dunin-Barkowski, W L; Orem, J M (1998) Suppression of diaphragmatic activity during spontaneous ponto-geniculo-occipital waves in cat. Sleep 21:671-5
Anderson, C A; Dick, T E; Orem, J (1996) Respiratory responses to tracheobronchial stimulation during sleep and wakefulness in the adult cat. Sleep 19:472-8
Orem, J (1996) Excitatory drive to the respiratory system in REM sleep. Sleep 19:S154-6
Orem, J; Anderson, C A (1996) Diaphragmatic activity during REM sleep in the adult cat. J Appl Physiol 81:751-60

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