Figure 2.

Robust memory is not immune to the ZIP effect in cortex. (A) Three consecutive CTA training sessions (CS = saccharin) generated robust memory. ZIP was administrated to the IC 1 wk after training and significantly disrupted the memory, as shown in successive tests, 1 d apart. (B) Two successive CTA trainings (CS = NaCl) generated a strong memory, which is resistant to extinction by three consecutive tests (Tests 1–3; open and filled circles represent the groups of rats which were subsequently used as control and ZIP injected, respectively). Microinfusion of ZIP into the IC 24 d later abolished memory performance, while the control rats still showed marked preference to water (Tests 4 and 5).