Learning performance of normal and mutant Drosophila after repeated conditioning trials with discrete stimuli.
A new olfactory conditioning procedure is described using short training trials with discrete presentation of conditioned stimuli (CS) and unconditioned stimuli (US). A short odor presentation along with a single-shock stimulus produced modest but reliable and reproducible learning. Multiple trials presented sequentially improved performance with increasing trial number. Trial spacing had a significant impact on performance. Two trials presented with a short intertrial interval (ITI) produced no improvement over a single trial; two trials with a 15 min ITI significantly boosted performance. This effect required two associative trials, because substituting one of the trials with the CS alone, US alone, or an unpaired CS-US failed to boost performance. The increase in initial performance with two trials decayed within 15 min after training. Thus, the effect is short-lived. The utility of using a battery of tests, including a single short trial, two massed trials, and two spaced trials, to investigate parameters of memory formation in several mutants was demonstrated.
Beck
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CD
Department of Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
Schroeder
B
B
Davis
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RL
D000483:Alleles; D000818:Animals; D003216:Conditioning, Operant / Q000502:physiology*; D004330:Drosophila; D004558:Electric Stimulation; D007858:Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology; D009154:Mutation; D010641:Phenotype; D012903:Smell / Q000502:physiology*; D013997:Time Factors