IBCN   20355
INSTITUTO DE BIOLOGIA CELULAR Y NEUROCIENCIA "PROFESOR EDUARDO DE ROBERTIS"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
In the search for the behavioral tag
Autor/es:
D. MONCADA; C. MARTINEZ; F. BALLARINI; N. ALEN; H. VIOLA
Lugar:
Washington, DC, ESTADOS UNIDOS
Reunión:
Congreso; Neuroscience Meeting Planner; 2008
Institución organizadora:
Society for Neuroscience
Resumen:
We have recently demonstrated the existence of a behavioral analogue of the synaptic tagging and capture process by using two different learning tasks: a weak inhibitory avoidance training (wIA) that induces short- but not long-term memory (S/LTM), and the exploration to a novel open field (OF). The combination of both paradigms in a critical time window enabled the consolidation of the IA-STM into IA-LTM. This effect depends on both, hippocampal integrity of the translational machinery after the OF exploration and dopamine D1/D5 receptors functionality during exposure to that novel arena. We propose that in this behavioral tagging model the OF synthesize proteins that will be captured in the tag set by the wIA.Open Field exploration promoted IA-LTM formation when performed between -1 h and +1 h (respect to IA training), with exception of a brief period comprising -30 to +0 min. We believe that the negative influence of the OF on the IA-LTM promotion occurs by a restraint in the tagging formation. Consistently we observed that when the OF exploration was performed 5 min before wIA training, not only did not promote IA-LTM but also impaired the promotion induced by an OF exploration performed 1 h before training. In contrast, when the second OF exploration was performed 15 min after wIA training (instead of 5 min pre), an improved IA-LTM was observed respect to animals that explored only one OF; concluding that IA tag setting could be impaired by a behavioral task preformed close to training.Then, we decided to investigate the nature of the IA tag itself, studying the role of several protein kinases, previously found to be needed in the formation of IA memory or in the LTP tagging process, particularly focusing in αCAMKII, PKA, PKMζ and ERK 1/2. Our results showed that inhibition of αCAMKII, PKA and PKMζ close to IA training impaired the promotion of IA-STM into IA-LTM, normally induced by the exposure to a novel OF one hour before a wIA.In sum, our results demonstrate, that IA-LTM promoted by the exposure to OF depends on both, protein synthesis elicited by OF exploration, and the correct setting of a mark induced by the wIA training. Moreover, if the tag is properly set, the positive influence of two OF exposure promotes a larger IA-LTM than the obtained with a single OF exploration, probably reflecting that the presence of more proteins in the neuronal substrate allows an improved capture in the IA-tagged synapses. Finally, we show suitable candidates to take part of the tagging machinery. As these kinases are normally involved in LTM formation, our results also provide an explanation for their function in the early stages of memory formation processes