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