Memory extinction, learning anew, and learning the new: dissociations in the molecular machinery of learning in cortex.
The rat insular cortex (IC) subserves the memory of conditioned taste aversion (CTA), in which a taste is associated with malaise. When the conditioned taste is unfamiliar, formation of long-term CTA memory depends on muscarinic and beta-adrenergic receptors, mitogen-activated protein kinase (MAPK), and protein synthesis. We show that extinction of CTA memory is also dependent on protein synthesis and beta-adrenergic receptors in the IC, but independent of muscarinic receptors and MAPK. This resembles the molecular signature of the formation of long-term memory of CTA to a familiar taste. Thus, memory extinction shares molecular mechanisms with learning, but the mechanisms of learning anew differ from those of learning the new.
Berman
D E
DE
Department of Neurobiology, The Weizmann Institute of Science, Rehovot 76100, Israel.
Dudai
Y
Y
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D000841:Anisomycin / Q000494:pharmacology; D002540:Cerebral Cortex / Q000378:metabolism / Q000502:physiology*; D003213:Conditioning, Psychological; D005108:Extinction, Psychological / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D018021:Lithium Chloride / Q000494:pharmacology; D020935:MAP Kinase Signaling System; D008297:Male; D008568:Memory / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D018727:Muscarinic Antagonists / Q000494:pharmacology; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism; D012054:Reinforcement, Psychology; D012439:Saccharin; D013649:Taste
D000319:Adrenergic beta-Antagonists; D018727:Muscarinic Antagonists; D011500:Protein Synthesis Inhibitors; D011943:Receptors, Adrenergic, beta; D011976:Receptors, Muscarinic; D016194:Receptors, N-Methyl-D-Aspartate; D000841:Anisomycin; D020928:Mitogen-Activated Protein Kinases; D012439:Saccharin; D018021:Lithium Chloride