Prenatal exposure to vanilla or alcohol induces crawling after these odors in the neonate rat: The role of mu and kappa opioid receptor systems

Prenatal Alcohol Exposure as a Case of Involuntary Early Onset of Alcohol Use: Consequences and Proposed Mechanisms From Animal Studies

“…The appetitive learning acquired in utero after alcohol exposure can also account for the increased preference or enhanced behavioral response to the odor of alcohol observed from newborns to adult rats (Youngentob et al, 2007;Eade et al, 2009Eade et al, , 2010Middleton et al, 2009;March et al, 2013b;Gaztañaga et al, 2015). Interestingly, similar results have been reported in humans.…”

“…Some studies explain postnatal increased alcohol intake in terms of a mere stimulus exposure effect, that is, familiarity with the alcohol flavor, or habituation to neophobia, which facilitates the initial acceptance of the particular chemosensory aspects of alcohol (Spear and Molina, 2005;Díaz-Cenzano and Chotro, 2010). However, this mechanism alone is not sufficient to explain the increased alcohol consumption observed when subjects are tested repeatedly and/or after a long period after the prenatal experience (Fabio et al, 2015;Gaztañaga et al, 2015).…”

“…A mechanism that has been broadly investigated and has obtained abundant support in the last two decades, is one that links increased alcohol consumption to fetal associative learning about alcohol (Chotro and Arias, 2003;Chotro, 2005a,b, 2006;Chotro et al, 2007Chotro et al, , 2009Díaz-Cenzano and Chotro, 2010;Miranda-Morales et al, 2010;Youngentob et al, 2012;Díaz-Cenzano et al, 2014;Bordner and Deak, 2015;Gaztañaga et al, 2015). The working hypothesis of most of these studies begins with the assumption that the fetus acquires an appetitive conditioned response to alcohol by the formation of an association between the flavor of alcohol (the conditioned stimulus) and its pharmacological effects (the reinforcer).…”

“…In addition to the enhanced response to alcohol odor, the prenatal experience has been observed to increase the reinforcing capacity of alcohol in operant conditioning tasks (March et al, 2009;Miranda-Morales et al, 2010;Gaztañaga et al, 2015); and has also been shown to interact with postnatal conditioning, potentiating appetitive learning about alcohol and retarding the acquisition of an aversion to this substance (Arias and Chotro, 2006;Chotro et al, 2009). The enhanced appetitive reinforcing properties of alcohol, together with the development of tolerance and reduced sensitivity to alcohol's aversive effects, have also been proposed as mechanisms by which prenatal alcohol may lead to high postnatal alcohol consumption (Arias et al, 2008;Pautassi et al, 2012;Fabio et al, 2015;Gore-Langton and Spear, 2019).…”

Early ontogeny as a unique developmental epoch for learning, memory and consequences of alcohol exposure: A Festschrift to honor the work of Dr. Norman E. Spear

“…They found greater consumption of an aversive solution (quinine), but not of a palatable one (saccharin) in the presence of the familiar odor cue, suggesting that neonatal rats were more accepting of (normally aversive) substances in the presence of familiar cues. Gaztanaga et al [7] (this issue) tested a similar hypothesis regarding how early sensory experiences via the chemical senses (odorant and tastant) impact later chemosensory preferences. They found that prenatal exposure to either vanilla or alcohol odor led to increased neonatal crawling behavior when rat pups were re-exposed to the same cue.…”