Reversible downregulation of protein kinase a during olfactory learning using antisense technique impairs long-term memory formation in the honeybee,Apis mellifera
A. Fiala et al., Reversible downregulation of protein kinase a during olfactory learning using antisense technique impairs long-term memory formation in the honeybee,Apis mellifera, J NEUROSC, 19(22), 1999, pp. 10125-10134
In this study, we examined the role of cAMP-dependent protein kinase (PKA)
in associative olfactory learning of the honeybee, Apis mellifera. In the b
ee, specific interference with molecules to clarify their role in a certain
behavior is difficult, because genetic approaches, such as mutants or tran
sgenic animals, are not feasible at the moment. As a new approach in insect
s in vivo, we report the use of short antisense oligonucleotides. We show t
hat phosphorothioate-modified oligodeoxynucleotides complementary to the mR
NA of a catalytic subunit of PKA directly injected into the bee brain cause
a reversible and specific downregulation of both the amount of the catalyt
ic subunit and of PKA activity by 10-15%. The amounts of the regulatory sub
unit of PKA, as well as PKC, are not affected. The slight "knockdown" of PK
A activity during the training procedure, a classical olfactory conditionin
g of the proboscis extension reflex, neither affects acquisition nor memory
retention 3 or 6 hr after training. However, it causes an impairment of lo
ngterm memory retention 24 hr after training. Downregulation of PKA 3 hr af
ter training has no detectable effect on memory formation. We conclude that
PKA contributes to the induction of a long-term memory 24 hr after trainin
g 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.