Fig. 3
From: Criteria for identifying the molecular basis of the engram (CaMKII, PKMzeta)
Use of the erasure test. a (Top) Protocol for testing the effect of PKM-zeta antisense (injected into hippocampus) on 1-day memory. (Bottom) Grey lines show track of rat on rotating platform that moved the rat into triangular shock zone defined relative to the room. After injection of scrambled DNA, the rat learned to avoid the shock zone and remembered 1 day later. If antisense was injected into the brain during multiple phases of the learning process, 1-day retention was abolished. Because the antisense was present during learning and probably also during retention, the failure of memory may be due to effects on induction or expression processes and thus do not provide specific information about the maintenance process. From [15] b. (left) Maximal LTP was induced by 4 tetani delivered to the CA1 region of a hippocampal slice. Bath application of tatCN21, a peptide that interferes with CaMKII function, produced a decrease in response that persisted after removal of tatCN21. Erasure of LTP was confirmed by the fact that LTP could then be reinduced (right). From [50]