Passive avoidance memory consolidation and reinstatement in the young rat.
Young rats (16-30 days), trained on a one-trial passive avoidance task, were subsequently submitted to the amnesic agent hypothermia 0, 5, 10, 20 or 30 min later, and tested for retention 6 h after training. While hypothermia administered 10 min after training was no longer effective in 30-day rats, it still induced a significant retrograde amnesia in younger animals. In 16- and 18-day rats, administration of hypothermia 20 min after training could still produce a slight but statistically non-significant amnesia. Additionally, exposition to a reinstatement treatment was found to alleviate the amnesic effects of hypothermia in 20- and 30-day-old animals, while it seemed ineffective in 16- and 18-day rats. These findings suggest that the more immature the animal, the longer the consolidation period, the more vulnerable the mnemonic trace, and the less effective a reinstatement treatment for alleviation of retrograde amnesia.
Blozovski
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D
Université Pierre et Marie Curie, C.N.R.S. 1199, Département de Neurophysiologie Comparée, Paris, France.
Buser
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P
D000375:Aging / Q000502:physiology*; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D007035:Hypothermia / Q000503:physiopathology; D008568:Memory / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000502:physiology; D012153:Retention, Psychology / Q000502:physiology*