Human fetal ethanol exposure is strongly associated with ethanol avidity during adolescence. Evidence that intrauterine olfactory experience influences chemosensory-guided postnatal behaviors suggests that an altered response to ethanol odor resulting from fetal exposure may contribute to later abuse risk. Using behavioral and neurophysiological methods, the authors tested whether ethanol exposure via the dam's diet resulted in an altered responsiveness to ethanol odor in infant and adult rats. Compared with controls, (a) fetal exposure tuned the neurophysiologic response of the olfactory epithelium to ethanol odor at some expense to its responsiveness to other odorants in infantile rats-this effect was absent in adults; (b) the neural effect in infantile rats was paralleled by an altered behavioral response to ethanol odor that was specific to this odorant-this effect was also absent in adults; and (c) a significant component of the infantile behavioral effect was attributable to ethanol's effect on the olfactory neural modality. These data provide evidence for an important relationship between prenatal ethanol experience and postnatal behavioral responsiveness to the drug that is modulated or determined by olfactory function.
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NIH-PA Author ManuscriptThe chemical senses are among the earliest systems to develop (Gottlieb, 1971;Schaal & Orgeur, 1992;Smotherman & Robinson, 1990), and in the chemosensory world of the uterus, they may have a unique salience. This statement is of potential significance to the field of ethanol research given that clinical and epidemiological studies provide strong data for a predictive relationship between prenatal ethanol exposure and the risk for ethanol abuse in adolescent and young adults (Alati et al., 2006;Baer, Bar, Bookstein, Sampson, & Streissguth, 1998;Streissguth, 1998;Yates, Cadoret, Troughton, Steward, & Giunta, 1998).It is well documented that olfactory function is fundamental to regulating a variety of biological processes, such as reproduction, food intake, and different social behaviors. Even communication between conspecific and heterospecific animals relies heavily on the reception and processing of odors produced by body glands and even feces and urine. Given this profound level of functional importance, not surprisingly, experience-induced plasticity in response to odorants is a means by which the olfactory system can be tuned to emphasize the transduction of stimuli that are deemed relevant within the animal's environment (Hudson, 1993(Hudson, , 1999. A variety of data indicate that the olfactory system is plastic in response to the odorant environment and have been gathered using different experimental manipulations, such as selective odorant exposure in neonates (Coopersmith & Leon, 1984;Johnson, Woo, Duong, Nguyen, & Leon, 1995;McCollum, Woo, & Leon, 1997;McLean & Harley, 2004;Sullivan & Leon, 1986;Sullivan, McGaugh, & Leon, 1991;Sullivan, Wilson, & Leon, 1989;Woo, Coopersmith, & Leon, 1987;Wo...
