Short- and long-term memory in Drosophila require cAMP signaling in distinct neuron types.
BACKGROUND
A common feature of memory and its underlying synaptic plasticity is that each can be dissected into short-lived forms involving modification or trafficking of existing proteins and long-term forms that require new gene expression. An underlying assumption of this cellular view of memory consolidation is that these different mechanisms occur within a single neuron. At the neuroanatomical level, however, different temporal stages of memory can engage distinct neural circuits, a notion that has not been conceptually integrated with the cellular view.


RESULTS
Here, we investigated this issue in the context of aversive Pavlovian olfactory memory in Drosophila. Previous studies have demonstrated a central role for cAMP signaling in the mushroom body (MB). The Ca(2+)-responsive adenylyl cyclase RUTABAGA is believed to be a coincidence detector in gamma neurons, one of the three principle classes of MB Kenyon cells. We were able to separately restore short-term or long-term memory to a rutabaga mutant with expression of rutabaga in different subsets of MB neurons.


CONCLUSIONS
Our findings suggest a model in which the learning experience initiates two parallel associations: a short-lived trace in MB gamma neurons, and a long-lived trace in alpha/beta neurons.
Blum
Allison L
AL
Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.
Li
Wanhe
W
Cressy
Mike
M
Dubnau
Josh
J
D000262:Adenylyl Cyclases / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D000818:Animals; D030801:Animals, Genetically Modified; D001362:Avoidance Learning / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology; D000242:Cyclic AMP / Q000502:physiology*; D029721:Drosophila Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D005260:Female; D055786:Gene Knockout Techniques; D005816:Genetic Complementation Test; D008297:Male; D008568:Memory / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology; D024521:Mushroom Bodies / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000145:classification / Q000502:physiology*; D017354:Point Mutation; D011993:Recombinant Fusion Proteins / Q000502:physiology; D012153:Retention, Psychology / Q000502:physiology; D015290:Second Messenger Systems / Q000502:physiology*; D012903:Smell / Q000502:physiology
D029721:Drosophila Proteins; D011993:Recombinant Fusion Proteins; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; C479926:Rut protein, Drosophila