Perinates associate ethanol´s sensory cues with the drug´s depressive respiratory effects: latter re-exposure to ethanol odor generates conditioned breathing depression.

MACCHIONE, AF; CULLERE, M; HAYMAL, BO; ABATE, P; MOLINA, JC

Valencia

Congreso; 15th Congress of the European Society for Biomedical Research on Alcoholism.; 2015

Breathing depressions endanger the neurological wellbeing of human babies. In different species, intrauterine alcohol exposure exerts dramatic effects on fetal breathing patterns. Prior research also shows that perinates smell ethanol in the amniotic fluid following maternal ingestion of the drug and that they associate these cues with different physiological effects of the drug. In this study (Experiment 1), pregnant rats were exposed to 0.0 or 2.0 g/kg ethanol during late pregnancy. During postnatal day 7 (PD7), pups representative of these gestational treatments received an i.g. administration of 0.0, 0.5, 1.0 or 2.0 g/kg ethanol. Neonates were evaluated using a whole body plethysmograph scented or not with ethanol odor. Ethanol exerted dose dependent effects upon breathing frequencies and apneic alterations. These effects were exacerbated in pups with prior prenatal exposure to the drug and tested under the presence of ethanol odor. In Experiment 2, pups during PDs 3-7 (developmental stage equivalent to the 3rd human gestational trimester) experienced ethanol odor or an unscented chamber under a state of sobriety or when intoxicated (2.0 g/kg ethanol). At PD9, pups were exposed to the smell of the drug while sober. Pups that originally experienced ethanol odor associated with the state of intoxication exhibited a dramatic conditioned respiratory depression. These results indicate that: a) minimal prenatal ethanol exposure sensitizes the organism to the drug´s detrimental effects upon respiration and b) the smell of the drug acts as a conditioned stimulus capable of modulating or generating breathing depressions and apneic disruptions.