T Wigal — Page 2 | PubMed Health

PubMed1988

Effects on the partial reinforcement extinction effect and on physical and reflex development of short-term in utero exposure to ethanol at different periods of gestation.

Ethanol was intubated into pregnant rats at Gestational Days 7-9 (G7-9) or 14-16 (G14-16). At both gestational ages, ethanol intubation affected reflex development but not physical development of resulting offspring. At G14-16, but not at G7-9, ethanol intubation resulted in the elimination of the partial reinforcement extinction effect when pups were tested at 15 days of age. These latter results confirm and extend previous ones in which ethanol was administered in a liquid diet throughout gestation.

Animals↗

PubMed1984

Familiar contextual odors promote discrimination learning in preweanling but not in older rats.

For rats 16- or 28-days-old postnatal, we tested the source of the facilitation in instrumental learning provided by odors from home nest materials. Three experiments confirmed that acquisition of a spatial discrimination (to escape footshock) was facilitated not only by the presence of typical nest odors in the training context, but also by the presence of a non-rat odor (banana) to which the animals had been familiarized for 4 hr/day for 7 days. There was a borderline tendency for a similar facilitation after familiarization to the latter odor for only 10 min. These effects occurred for rats 16 days postnatal but not for those 28 days old. The experiments also confirmed that the prior exposure to non-rat odors did not in itself, in the absence of that odor during learning, affect discriminated escape learning, and that enhanced affinity for a contextual odor is not a sufficient condition for enhancement of learning in its presence. There was some indication that the 16-day-old rat was more likely to select a discriminative odor to guide their choice of spatial locations if a familiar contextual odor was present.

Aging↗