Effects of a conditional Drosophila PKA mutant on olfactory learning and memory.
The requirement for cAMP-dependent protein kinase (PKA) in associative learning of Drosophila was assessed in mutant flies hemizygous for a cold-sensitive allele, X4, of the DC0 gene, which encodes the major catalytic subunit of PKA. DC0X4 hemizygotes died as third-instar larvae at 18 degrees C, the restrictive temperature, but were viable when raised at 25 degrees C. Shifting adult DC0X4 hemizygotes from 25 degrees C to 18 degrees C led to a decrease in PKA activity from 24% to 16% of wild-type without impairing viability. At 25 degrees C, DC0X4 hemizygotes exhibited reduced initial learning relative to controls but normal memory decay in a Pavlovian olfactory learning assay. Shifting the temperature from 25 degrees C to 18 degrees C prior to training reduced initial learning to a similar extent in DC0X4 hemizygotes and controls but resulted in a steeper memory decay curve only in DC0X4 hemizygotes. These observations are suggestive of a role for PKA in medium-term memory formation in addition to its previously established role in initial learning.
Li
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Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
Tully
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Kalderon
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D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology; D004330:Drosophila; D007858:Learning / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology*; D009154:Mutation / Q000502:physiology*; D009420:Nervous System / Q000201:enzymology; D011494:Protein Kinases / Q000378:metabolism; D012903:Smell / Q000235:genetics* / Q000502:physiology*
D011494:Protein Kinases