The Journal of Neuroscience, November 15, 1999, 19(22):10125-10134
Reversible Downregulation of Protein Kinase A during Olfactory
Learning Using Antisense Technique Impairs Long-Term Memory Formation
in the Honeybee, Apis mellifera
André
Fiala,
Uli
Müller, and
Randolf
Menzel
Institut für Neurobiologie der Freien Universität
Berlin, 14195 Berlin, Germany
In this study, we examined the role of cAMP-dependent protein
kinase (PKA) in associative olfactory learning of the honeybee, Apis mellifera. In the bee, specific interference with
molecules to clarify their role in a certain behavior is difficult,
because genetic approaches, such as mutants or transgenic animals, are not feasible at the moment. As a new approach in insects in
vivo, we report the use of short antisense oligonucleotides. We
show that phosphorothioate-modified oligodeoxynucleotides
complementary to the mRNA of a catalytic subunit of PKA directly
injected into the bee brain cause a reversible and specific
downregulation of both the amount of the catalytic subunit and of PKA
activity by 10-15%. The amounts of the regulatory subunit of PKA, as
well as PKC, are not affected. The slight "knockdown" of PKA
activity during the training procedure, a classical olfactory
conditioning of the proboscis extension reflex, neither affects
acquisition nor memory retention 3 or 6 hr after training. However, it
causes an impairment of long-term memory retention 24 hr after
training. Downregulation of PKA 3 hr after training has no detectable
effect on memory formation. We conclude that PKA contributes to the
induction of a long-term memory 24 hr after training when activated
during learning. Second, we demonstrate that the antisense technique is
feasible in honeybees in vivo and provides a new and
powerful tool for the study of the molecular basis of learning and
memory formation in insects.
Key words:
antisense oligonucleotides; Apis mellifera; cAMP-dependent protein kinase; honeybee; insect; long-term memory; olfactory learning; PKA
Copyright © 1999 Society for Neuroscience 0270-6474/99/192210125-10$05.00/0
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