INVESTIGADORES
ROMANO Arturo Gabriel
congresos y reuniones científicas
Título:
labilize or not to labilize? The importance of being proteasome
Autor/es:
FUSTIÑANA, MARIA SOL; FREUDENTHAL, RAMIRO; ROMANO, ARTURO
Lugar:
Florencia
Reunión:
Congreso; 8th IBRO World Congress; 2011
Institución organizadora:
International Brain Research Organization
Resumen:
Once a memory is consolidated, the
presentation of a reminder can induce reconsolidation, a process that has
inherent stages: reactivation, labilización and restabilization of the memory
trace. We are studying the labilization process in two contextual associative
models in phylogeneticaly distant species: context-signal memory in
the crab Chasmagnathus and fear conditioning in mouse.
We analysed the role of the proteasome system
in memory labilization. A previous study indicated that the labilization process
involved protein degradation by the proteasome. Here we found that the inhibition of the proteasome
system by MG132 block labilization. Our laboratory had shown that this drug is
capable to inhibit NF-kB during consolidation and the inhibition of this
transcription factor results in an amnesic effect. Paradoxically, when we
administered MG132 previous the re-exposure we did not find an amnesic effect
on memory reconsolidation. However, when we co-injected this proteasoma
inhibitor with sulfasalazine (a NF-kB inhibitor) we could not find the amnesic effect we used to obtain
after sulfasalazine administration previous to the reexposure. It had been
demonstrated that bicuculline, a GABA inhibitor can facilitate memory
reconsolidation in the crab paradigm. Hence we co-injected bicuculline with
MG132 and we were incapable to facilitate memory reconsolidation. When we
co-administered MK801, a NMDA receptor inhibitor with MG132, we also coud not
find the amnesic effect of MK801. All together these results indicate that
proteasoma is involved in memory labilization. The hypothesis underlying is that
memory labilization implies at least partial synapses retraction involving
proteasoma dependent protein degradation and then stabilization during the
reconsolidation process.