title: A molecular mechanism underlying gustatory memory trace for an association in the insular cortex.
abstract: Events separated in time are associatively learned in trace conditioning, recruiting more neuronal circuits and molecular mechanisms than in delay conditioning. However, it remains unknown whether a given sensory memory trace is being maintained as a unitary item to associate. Here, we used conditioned taste aversion learning in the rat model, wherein animals associate a novel taste with visceral nausea, and demonstrate that there are two parallel memory traces of a novel taste: a short-duration robust trace, lasting approximately 3 hr, and a parallel long-duration weak one, lasting up to 8 hr, and dependent on the strong trace for its formation. Moreover, only the early robust trace is maintained by a NMDAR-dependent CaMKII- AMPAR pathway in the insular cortex. These findings suggest that a memory trace undergoes rapid modifications, and that the mechanisms underlying trace associative learning differ when items in the memory are experienced at different time points.
authors.affiliation: Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.
authors.forename: Chinnakkaruppan
authors.initials: C
authors.lastname: Adaikkan
authors.affiliation: Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.|Center for Gene Manipulation in the Brain, University of Haifa, Haifa, Israel.
authors.forename: Kobi
authors.initials: K
authors.lastname: Rosenblum
mesh_terms: D000818:Animals; D001362:Avoidance Learning; D002540:Cerebral Cortex / Q000502:physiology*; D003214:Conditioning, Classical; D008568:Memory; D051381:Rats; D013649:Taste
keywords: consolidation; multiple memory trace; neuroscience; protein kinase; rat