Figure 5.

Aminergic pathways underlying gustatory SER conditioning. (a) Antennal discrimination learning of 1 M sucrose vs. 3 M NaCl in control bees. PBS-injected bees (n = 85) learned the discrimination and remembered it 1 h later. (b) Blockade of octopaminergic signaling for 3 M NaCl (+) vs. 1 M sucrose (−). Δ_disc values of epinastine-injected bees (n = 88) show that the discrimination was learned and retained, thus showing no effect of octopaminergic blockade. (c) Blockade of octopaminergic signaling for 1 M sucrose (+) vs. 3 M NaCl (−). Δ_disc values of epinastine-injected bees (n = 64) show that in this case the discrimination was not learned; retention, although significant, reached only 15%. (d) Blockade of dopaminergic signaling for 3 M NaCl (+) vs. 1 M sucrose (−). Flupentixol-injected bees (n = 86) did not learn the discrimination and therefore did not exhibit significant retention. (e) Blockade of dopaminergic signaling for 1 M sucrose (+) vs. 3 M NaCl (−). Flupentixol-injected bees (n = 64) did neither learn nor memorize the gustatory discrimination. NS: non-significant; *P < 0.05; **P < 0.01, ***P < 0.0001. Error bars on Δ_disc levels represent 95% confidence intervals.