Neonatal expression of respiration frequency as a function of pre and postnatal exposure to moderate ethanol doses and alcohol related sensory cues.

CULLERÉ, ME; SPEAR, N.E.; MOLINA, J.C.

San Francisco

Congreso; 35th Annual Scientific Meeting of the Research Society on Alcoholism; 2012

Research Society on Alcoholism

NEONATAL DEPRESSION OF RESPIRATION FREQUENCY AS A FUNCTION OF PREAND POSTNATAL EXPOSURE TO MODERATE ETHANOL DOSES AND ALCOHOLRELATED SENSORY CUES Cullere´ , ME, Spear, NE, Molina JC Instituto de Investigacio´n Me´dica Mercedes y Martı´n Ferreyra, Co´rdoba, Argentina Human and animal studies indicate a substantial depression of fetal respiration rates as a function of maternal ethanol intoxication. This effect seems to be linked with a variety of factors; among others hypoxia due to vasoconstriction of blood vessels in the umbilical cord, hypercanea, direct action of the drug upon neural systems controlling fetal breathing and suppression of fetal activity. In a variety of preclinical studies, we have observed that rat fetuses sense ethanol-related sensory cues when the drug accumulates in the amniotic fluid. In addition, the near term fetus also exhibits pavlovian conditioning when these cues are contigous with different unconditioned effects of the drug such as maternal hypothermia. The hypothesis under analysis in the present study is linked to the possibility of establishing early conditioned respiration responses as a function of the explicit association between ethanol odor sensed in utero in contiguity with depressed respiratory frequency. In this study we also examined whether prenatal exposure to the drug either results in infantile sensitization or tolerance in terms of respiration frequencies when the developing organism experiences different ethanol doses. Pregnant dams (gestational days 17?20) received a daily intragastric administration of 2.0 g/kg ethanol or water (vehicle). At postnatal day 7, infants either received i.g. administration of vehicle, 0.5, 1.0 or 2.0 g/kg ethanol. Respiration rates were evaluated in freely behaving unrestrained pups by whole body flow through plethysmography. These evaluations took place under the presence or absence of ethanol odor. As expected, relatively high ethanol doses resulted in depressed respiration rates. Pertinent ANOVAs and post-hoc comparisons also indicated that pups prenatally exposed to ethanol exhibit marked sensitization to the depressant effects of the drug particularly when ethanol odor was present. These results strongly suggest that prenatal ethanol experience results in conditioned respiration patterns that may endanger the physiological wellbeing of the infant when reexposed to ethanol sensory cues or the combination of these cues and the process of ethanol intoxication.