WP SMOTHERMAN's research while affiliated with Binghamton University and other places

... By what structural and/or dynamical mechanisms prenatal exposure to cocaine influences fetal development remains an open question. Our investigations examined the effects of cocaine in an experimental animal model that permits drug administration to individual fetal subjects followed by quantitative observation of their motor behaviors over time (Simonik et al., 1993Simonik et al., , 1994). These studies have shown that cocaine administered into the peripheral circulation or directly into the central nervous system of individual fetal rats produces three-to four-fold increases in motor activity in the forelimbs and hindlimbs lasting several minutes. ...

... Observation of fetuses in uterus provides the closest approximation to the natural prenatal environment, and preparation of fetuses in amnion and in bath permits a detailed analysis of fetal movements and precise control over chemosensory and tactile stimulation. These techniques have been successfully applied to the analysis of age-related change in fetal behavior (Smotherman and Robinson, 1986); the emergence of behavioral organization (Smotherman and Robinson, 1986); fetal sensory capabilities (Smotherman and Robinson, 1985a); fetal learning and responsiveness to conditioned stimuli in utero (Smotherman and Robinson, 1985b); and the effect of experimentally induced behavioral suppression in utero on the development of subsequent physical anomalies (Barron, Riley, and Smotherman, 1986;Smotherman, Woodruff, Robinson, del Real, Barron, and Riley, 1986b). Each of these areas of inquiry is discussed below. ...

... Generally, it is assumed that changes in the uterine environment are capable to exert long-lasting changes in behaviour and physiology[31][32][33][34]. Already during prenatal development, motor-sensory and cognitive behaviours can be observed in rodents[35,36]. Testing learning abilities in utero is challenging and was conducted during the last day of uterine life in rats in a taste/odour aversion learning task[36]. In mice, possibly due to size limitations, tasks investigating early learning have been conducted more focused on the postnatal phase, with successful conditioning as early as PND 3[37]. ...

... Before being re-exposed to pairings of ethanol and naloxone, animals in the present experiments had experienced ethanol or sucrose reinforcement for two consecutive trials. Opioid activity (specifically, μ-opioid receptors) can be conditioned after pairing a chemosensory CS with a US that promotes the release of endogenous opioids, and subsequently, the animal is capable of exhibiting a conditioned opioid response when the CS is again presented (Arnold et al. 1993). So, given that both USs—ethanol and sucrose—are capable of releasing endogenous opioids [unconditioned response] , small quantities of these reinforcers acting as a CS may promote a similar conditioned opioid response that is counterconditioned or extinguished by the pairing with naloxone. ...