Fuitfly Memory Revisited
Apparently, this was the experiment to condition and test memory retention in fruitflies (thanks John for referring me to the article). Unfortunately I could not access the full article, so here is the summary:
Classical conditioning and retention in normal and mutantDrosophila melanogaster
Tim Tully1 and William G. Quinn1, 2
(1) Department of Biology, Princeton University, 08544 Princeton, New Jersey, USA (2) Present address: Whitaker College and Department of Biology, E25-436, Massachussetts Institute of Technology, 02139 Cambridge, MA, USA
Accepted: 1 April 1985
Summary
By changing the conditioned discrimination paradigm of Quinn et al. (1974) from an instrumental procedure to a classical (Pavlovian) one, we have demonstrated strong learning in type flies. About 150 flies were sequestered in a closed chamber and trained by explosing them sequentially to two odors in air currents. Flies received twelve electric shock pulses in the presence of the first odor (CS+) but not in the presence of the second odor (CS-). To test for conditioned avoidance responses, flies were transported to a Tmaze choice point, between converging currents of the two odors. Typically, 95% of trained flies avoided the shock-associated odor (CS+).
Acquisition of learning was a function of the number of shock pulses received during CS+ presentation and was asymptotic within one training cycle. Conditioned avoidance increased with increasing shock intensity or odor concentration and was very resistant to extinction. Learning was best when CS+ presentations overlap shock (delay conditioning) and then decreased with increasing CS-US interstimulus intervals. Shocking flies immediately before CS+ presentation (backward conditioning) produced no learning. Nonassociative control procedures (CS Alone, US Alone and Explicitly Unpaired) produced slight decreases in avoidance responses, but these affected both odors equally and did not alter our associative learning index (A).
Memory in wild-type flies decayed gradually over the first seven hours after training and still was present 24 h later. The mutantsamnesiac, rutabaga anddunce showed appreciable learning acquisition, but their memories decayed very rapidly during the first 30 min. After this, the rates of decay slowed sharply; conditioned avoidance still was measurable at least three hours after training.
Abbreviations OCT 3-octanol - MCH 4-methylcyclohexanol - C-S Canton-Special - CS conditioned stimulus - US unconditioned stimulus
Shocking, isn't it? Get it? Ha, I kill me.