Retention of CS-US association learned under ketamine anesthesia.
In order to assess learning possibilities under ketamine anesthesia, rats underwent a pavlovian conditioning (tone paired with foot-shock), and were subsequently tested in a conditioned suppression of lever pressing for food paradigm. First, two sessions of 70 trials were conducted, on 4 groups of anesthetized rats: a conditioned group (group C) experienced the tone (CS+) always paired with foot-shocks, whereas a discriminative group (group D) was submitted to a differential conditioning (CS+ followed by the US and a CS- always presented alone). Another group (habituated, H) received presentations of tone (CS+) alone and the fourth group (naive animals, N) was never anesthetized. Seven days later, while rats were pressing the lever to get food, CS+ presentations elicited a significant conditioned suppression of instrumental responses only in groups C and D. Moreover, a differential effect between CS+ and CS- was obtained for group D. These results indicate that a Pavlovian conditioning can occur under anesthesia, and then that its memory can last at least 7 days. The particular specific effects of ketamine are discussed to account for these results.
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JM
Département de Psychophysiologie, Laboratoire de Physiologie Nerveuse, C.N.R.S., Gif sur Yvette, France.
Neuenschwander-el Massioui
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D000768:Anesthesia, General; D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology*; D007649:Ketamine / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012153:Retention, Psychology / Q000187:drug effects*
D007649:Ketamine