A model of ventilatory instability induced in the unrestrained rat.
A classic conditioning paradigm was used to examine the hypothesis that perturbations during sleep in the neonate rat can have a lasting impact on breathing. During the first 4 wk of life, stimuli were presented to rats during behaviorally defined sleep. In a conditioned hypoxic (CH) group, brief periods of hypoxic gas were used as the unconditioned stimulus. Tactile and auditory stimuli were used as the conditioned stimuli. In a conditioned control (CC) group, air was used as the unconditioned stimulus. A third group of unconditioned control (UC) rats was not exposed to the conditioning paradigm. Animals were provided routine care for 3.5 mo; ventilation was then assessed using plethysmography. Conditioning during neonatal life produced increased ventilatory irregularities and apnea during behaviorally defined sleep in adult rats. Both CH and CC rats showed a significantly greater number of apneic events compared with UC rats. Over a 2-h sleep period, CH rats exhibited a total of 105.1 +/- 9.4 (SE) apneic events, CC rats 69.4 +/- 4.2 events, and UC rats 42.1 +/- 3.1 events [F(2,18) = 25.568; P < 0.0001]. These findings suggest that experiences in the first few weeks of life will alter ventilatory patterning in the adult animal.
Thomas
A J
AJ
Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106.
Austin
W
W
Friedman
L
L
Strohl
K P
KP
D000161:Acoustic Stimulation; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D001049:Apnea / Q000503:physiopathology; D001522:Behavior, Animal / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology; D005260:Female; D008954:Models, Biological; D010812:Physical Stimulation; D010991:Plethysmography; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D015656:Respiratory Mechanics / Q000502:physiology*; D012890:Sleep / Q000502:physiology*