Learning Performance of Normal and Mutant Drosophila after Repeated Conditioning Trials with Discrete Stimuli

• Published in: The Journal of neuroscience 2000-04, Vol.20 (8), p.2944-2953
• Main Authors: Beck, C. D. O, Schroeder, Bradley, Davis, Ronald L
• Format: Article
• Language: English
• Subjects: Alleles; Animals; Conditioning, Operant - physiology; Drosophila; Electric Stimulation; Learning - physiology; Memory - physiology; Mutation; Phenotype; Smell - physiology; Time Factors
• ISSN: 0270-6474; 1529-2401; 1529-2401
• DOI: 10.1523/jneurosci.20-08-02944.2000

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.