Fig. 1.

Conditioned courtship indicates that Notch dysfunction impairs long-term memory. (a) Short-term memory was examined 30 min after training. Wild-type (CS) and N^ts1 flies display intact short-term memory after 2 days in nonpermissive conditions.^*, Statistical differences between naïve and trained cohorts indicating memory of training (P = 0.0087 for CS and P = 0.0088 for N^ts1). (b) Long-term memory was examined 2 days after training. CS males show intact long-term memory (P = 0.0007 for CS) after 2 days in nonpermissive conditions, whereas N^ts1 flies do not demonstrate long-term memory. (c) Long-term memory was examined in flies maintained at permissive temperatures to test for developmental enfeeblement. Under permissive conditions, both CS and N^ts1 flies display statistically significant differences in naïve versus trained data sets, demonstrating the presence of long-term memory (P = 0.0188 for CS and P = 0.0003 for N^ts1). (d) Two-day long-term memory was examined in N^ts1 flies bearing heat shock-driven wild-type Notch transgene (N^ts1;hs-N⁺/+) or a phenotypically nonfunctional control Notch missing ligand-interaction domains (N^ts1;hs-ΔEgf-Ni/+). Only flies carrying functional Notch displayed statistically significant rescue of long-term memory (P = 0.0430 for N^ts1;hs-N⁺/+). These results indicate that requirements for long-term memory are specific for functional Notch. At least 15 flies were examined in every cohort shown.