Published in:
The Journal of Neuroscience, 29 (2009) 7, Seite 2225-2230
Language:
English
DOI:
10.1523/jneurosci.3789-08.2009
ISSN:
1529-2401;
0270-6474
Origination:
Footnote:
Description:
It is generally accepted that, after learning, memories stabilize over time and integrate into long-term memory (LTM) through the process of consolidation, which depends onde novoprotein synthesis. Besides, studies on several species have shown that reactivation of already stabilized LTM can either make this memory labile and then restabilize it (a process called reconsolidation) or inhibit it (extinction). However, the identity of both processes and their interactions with consolidation are still under debate. Regarding memory stabilization,Drosophilaoffers a striking exception since, in this species, LTM is not the sole stable form of memory. Under specific learning conditions, anesthesia-resistant memory (ARM) can be formed through processes yet unknown but that are resistant to cycloheximide, a classical protein synthesis inhibitor that impairs LTM. Here, we took advantage of this dichotomy to ask whether both ARM and LTM could be extinguished and/or reconsolidated. We also studied whether two forms of memory extinction and reconsolidation exist in flies, as for memory stabilization. We show that either reconsolidation or extinction can be induced after olfactory conditioning inDrosophila, depending on the number of reactivations as in other species. Furthermore, regarding the effect of cycloheximide, the ARM/LTM dichotomy for stabilization does not apply to extinction and reconsolidation. Blocking protein synthesis interfered with both processes regardless of whether initial stabilization was sensitive (LTM) or not (ARM) to cycloheximide. These results thus show thatDrosophilais a useful model to tackle these questions and that reconsolidation is not necessarily a mere repetition of consolidation.