Papassotiropoulos A, Stetak A, de Quervain DJ, Freytag V, Gabor Fenyves B, Demougin P, Probst S, Hadziselimovic N, Milnik A, Peter F, Hauser Y, Vukojevic V, Boglari C
[
J Neurosci,
2017]
The identification of genes related to encoding, storage, and retrieval of memories is a major interest in neuroscience. In the current study, we analyzed the temporal gene expression changes in a neuronal mRNA pool during an olfactory long-term associative memory (LTAM) in C. elegans hermaphrodites. Here we identified a core set of 712 (538 upregulated and 174 downregulated) genes that follow three distinct temporal peaks demonstrating multiple gene regulation waves in LTAM. Comparing with the previously published positive LTAM gene sets (Lakhina et al., 2015), 50% of the identified upregulated genes here overlap with the previous dataset, possibly representing stimulus-independent memory regulated genes. On the other hand, the remaining genes were previously not identified in positive associative memory, and may specifically regulate aversive LTAM. Our results suggest a multistep gene activation process during the formation and retrieval of long-term memory and define general memory implicated genes as well as conditioning-type dependent gene sets.SIGNIFICANCE STATEMENTThe identification of genes regulating different steps of memory is of major interest in neuroscience. Identification of common memory genes across different learning paradigms and the temporal activation of the genes is poorly studied. Here, We investigated the temporal aspects of C. elegans gene expression changes using aversive olfactory associative long-term memory (LTAM) and identified three major gene activation waves. Like previous studies, aversive LTAM is also CREB dependent, and CREB activity is necessary immediately following training. Finally, we define a list of memory paradigm independent core gene set as well as conditioning dependent genes.