Two-trial spaced training in Drosophila reveals that repetition and spacing in learning improves memory by similar mechanisms

CATTANEO V.Y PAGANI M.R.

Córdoba

Congreso; XXIX Congreso anual de la sociedad Argentina de investigación en neurociencias; 2014

Sociedad Argentina de Investigación en Neurociencias

Long-term memory (LTM) deficit has been detected in animal models of Neurofibromatosis type-1 (NF1) and Noonan syndrome (NS), two disorders caused by mutations that enhance the activity of ERK1/2. NF1 mutant mice and patients showed a memory improvement by additional training, whereas in animal models of NS the memory deficit can be restored by a longer spacing between trials of training. Therefore, it seems that two strategies can provide memory recovery in these models; however, the mechanisms involved remain obscure. Based on the time course of ERK activity during training we developed a protocol of training. Unexpectedly, our studies provide evidence indicating that both, over-training and longer spacing during training share the same molecular properties. We found that LTM can be produced by multiple trials of training with a regular spacing (7 trials spaced by 15 min) or by a fewer number of trials with a longer spacing (2 trials spaced by 30 min). Other memory (ARM) was unaffected by repetition or spacing. This suggested that repetition and spacing are equivalent since the ability of the long protocol to induce LTM can be substituted by a longer spacing in a short protocol. Memory produced by those protocols requires the same molecular component (i.e. the small G-protein RAS). Our studies support the idea that ERK activity during training can be used to design learning protocols which improves memory.