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Biomedical subjects

J F Pfister

Publications and source records attributed to J F Pfister.

3 recordsLinked to original sources
PubMed1997

Instrumental learning for a thermal reinforcer in 1-day-old rats.

One-day-old rats in a cool environment (25 degrees C) quickly acquired an instrumental response when rewarded with a 20-s warming of the platform (from 25 degrees C to 36 degrees C) on which they lay. The instrumental response, turning the head to one side, was learned within 30 min after the thermal contingency began and extinguished when the contingency was reversed. This experiment demonstrates rapid operant learning by neonates in a task that does not contain a Pavlovian stimulus-reinforcer contingency. The novel experimental method has wide applicability in psychology and neuroscience.

Animals↗
PubMed1984

Transitions in the dehydration-induced inhibition of milk intake in suckling rats.

The effects of acute cellular or extracellular dehydration on milk intake via suckling were determined in rats 5, 10, 15, and 20 days of age. Milk was made available 10 times to each rat pup by the intravenous infusion of oxytocin to anesthetized test dams. Prior to 15 days of age, milk intake was not affected by either intracellular or extracellular dehydration. In rats 15 days and older, however, both forms of dehydration reduced milk intake at the nipple. Thus, dehydration starts to inhibit suckling behavior at the onset of weaning, when food and water are both taken directly from the environment by the developing animal.

Animals↗