Figure 3.

Formation of an extinction memory after extinction with two CS-only trials is sensitive to protein synthesis inhibition when the animals are trained with a long US duration. On day 1, animals were subjected to three CS–US pairings (A1–A3) with a short (2 s, circles) or long (10 s, triangles) US presentation (acquisition). After 24 h, on day 2, emetine (black symbols) or PBS (gray symbols) was injected 30 min before two CS-only trials (E1, E2). On day 3, memory was tested (retention). Presented are percentages of bees showing the CR to the CS at different phases of the experiment. Asterisk indicates significant differences (p < 0.05). Arrow, Time of injection. Number of animals: long-Eme, n = 86; long-PBS, n = 72; short-Eme, n = 75; short-PBS, n = 89.