In utero release from a single transient hypoxic episode: a positive reinforcer?
In this experiment, fetal rats, Rattus norvegicus, were subjected to a single transient hypoxic episode before an injection of orange essence or isotonic saline through the uterine and amniotic membranes into the amniotic fluid within 5 s of the release from hypoxia. Other animals experienced either orange essence or isotonic saline alone following no hypoxic episode. At 120 days after birth, adult rats were given a two-choice preference test between orange and water. Only those animals who experienced the orange following release from hypoxia showed a preference for the orange. These results suggest that the acquired preference is not a result of simple exposure but is suggestive of a role for reoxygenation as a positive reinforcer.
Hepper
P G
PG
School of Psychology, Queen's University of Belfast, N. Ireland.
D000818:Animals; D001245:Association Learning / Q000502:physiology*; D002628:Chemoreceptor Cells / Q000502:physiology*; D005260:Female; D011939:Mental Recall / Q000502:physiology*; D010100:Oxygen / Q000502:physiology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012054:Reinforcement, Psychology; D013649:Taste / Q000502:physiology; D013650:Taste Buds / Q000502:physiology
D010100:Oxygen