Conditioned breathing depression during perinatal life as a function of associating ethanol odor and the drug´s intoxicating effects

MACCHIONE AF; HAYMAL BO; MOLINA JC

Foz de Iguazú

Congreso; PanAmerican Congress of Physiological Sciences (PanAm); 2014

Fetal ethanol exposure is a risk factor associated with the sudden infant death syndrome. Ethanol alters respiratory plasticity and sensitizes the organism to the drug´s depressant effects. In addition, human and rat fetuses perceive ethanol´s sensory cues present in the amniotic fluid and are capable of associating them with different physiological effects of the drug. In this study we analyzed the possibility of conditioned breathing responses in 3-9 day-old-rats (3rd gestational trimester in humans) mediated by the association between the odor of the drug and the state of intoxication. During postnatal days (PDs) 3, 5 and 7, pups sensed ethanol odor or were exposed to an unscented chamber. These experiences were associated with the administration of 0.0 or 2.0 g/kg ethanol (i.g). At PD9, all pups experienced ethanol odor while sober. Whole body plethysmography analyses indicated breathing depressions caused by ethanol intoxication during PDs 3, 5 and 7. At test (PD9) alcohol odor elicited a significant depression in breathing only in pups previously exposed to the sensory cue paired with ethanol intoxication. An additional pharmacokinetic profiles study indicated that this result was not related with changes in ethanol metabolism. The results indicate that brief experiences with the sensory cues of alcohol associated with non-teratological doses of the drug are sufficient to promote conditioned breathing depression.