The general objective is to study the neural basis for generation of respiratory patterns in the mammal, with special reference to: a) switching of the respiratory phases (inspiratory-expiratory [I-E] and expiratory-inspiratory [E-I]); b) augmenting (ramp) and decrementing patterns of I neuron activity. The general method of analysis is to ascertain time relations between different respiratory neuron activities, as influenced by perturbations that change respiratory pattern (e.g. vagal and superior laryngeal inputs that advance or retard phase-switching). The role of several respiratory neuron populations in pattern generation will be studied: 1) ventral respiratory group (VRG) neurons, including airway motoneurons (hypoglossal, laryngeal) and their associated premotor neurons; 2) pontine respiratory group (PRG) neurons (region of Kolliker-Fuse nucleus and nucleus parabrachialis medialis). Respiratory neural activity will be studied in relation to: 1) mechanisms of E-I phase-switching; 2) the slow time course of vagal afferent influence on I-E phase-switching; 3) the graded inhibition of airway motoneurons by vagal afferent inputs, and identification of afferent pathways to these neurons and their premotor neurons; 4) the role of rostral pontine respiratory neurons in phase-switching, and their afferent and efferent relations to medullary respiratory neurons. Experimental analysis will involve: 1) simultaneous recording of multiple signals (unit activity from several microelectrodes, mass activity from several respiratory motor nerves) and application of multiple test procedures; 2) phase-response and phase-locking analysis by use of timed delivery of inputs, with special reference to events immediately preceding the phase transitions; 3) intracellular recording to observe both slow and rapid time courses of events during the silent period of a neuron's activity; 4) study of connectivity by recording from multiple signals and application of cross-correlation and cross-spectral analysis (including detection of monosynaptic relations and use of high-frequency oscillation as a marker of connections). The studies are relevant to control of breathing during physiological and pathophysiological conditions, and in particular to the role of airway motoneurons in controlling airway resistance.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL027300-09A2
Application #
3339063
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Project Start
1981-04-01
Project End
1995-06-30
Budget Start
1990-07-01
Budget End
1991-06-30
Support Year
9
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Albert Einstein College of Medicine
Department
Type
Schools of Medicine
DUNS #
009095365
City
Bronx
State
NY
Country
United States
Zip Code
10461
Cohen, Morton I; Shaw, Chen-Fu (2004) Role in the inspiratory off-switch of vagal inputs to rostral pontine inspiratory-modulated neurons. Respir Physiol Neurobiol 143:127-40
Marchenko, Vitaliy; Granata, Antonio R; Cohen, Morton I (2002) Respiratory cycle timing and fast inspiratory discharge rhythms in the adult decerebrate rat. Am J Physiol Regul Integr Comp Physiol 283:R931-40
Cohen, M I; Shaw, C F; Huang, W X et al. (2001) Role of brainstem respiratory neuron types in phase-switching produced by afferent vagal stimulation. Adv Exp Med Biol 499:83-8
Nakazawa, K; Granata, A R; Cohen, M I (2000) Synchronized fast rhythms in inspiratory and expiratory nerve discharges during fictive vocalization. J Neurophysiol 83:1415-25
Huang, W X; Cohen, M I (2000) Population and unit synchrony of fast rhythms in expiratory recurrent laryngeal discharges. J Neurophysiol 84:1098-102
Huang, W X; Cohen, M I; Yu, Q et al. (1996) High-frequency oscillations in membrane potentials of medullary inspiratory and expiratory neurons (including laryngeal motoneurons). J Neurophysiol 76:1405-12
Cohen, M I; Yu, Q; Huang, W X (1995) Preferential correlations of a medullary neuron's activity to different sympathetic outflows as revealed by partial coherence analysis. J Neurophysiol 74:474-8
Christakos, C N (1994) Analysis of synchrony (correlations) in neural populations by means of unit-to-aggregate coherence computations. Neuroscience 58:43-57
Christakos, C N; Cohen, M I; Sica, A L et al. (1994) Analysis of recurrent laryngeal inspiratory discharges in relation to fast rhythms. J Neurophysiol 72:1304-16
Cohen, M I; Huang, W X; Barnhardt, R et al. (1993) Timing of medullary late-inspiratory neuron discharges: vagal afferent effects indicate possible off-switch function. J Neurophysiol 69:1784-7

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