title: Memory reconsolidation and its maintenance depend on L-voltage-dependent calcium channels and CaMKII functions regulating protein turnover in the hippocampus.
abstract: Immediate postretrieval bilateral blockade of long-acting voltage-dependent calcium channels (L-VDCCs), but not of glutamatergic NMDA receptors, in the dorsal CA1 region of the hippocampus hinders retention of long-term spatial memory in the Morris water maze. Immediate postretrieval bilateral inhibition of calcium/calmodulin-dependent protein kinase (CaMK) II in dorsal CA1 does not affect retention of this task 24 h later but does hinder it 5 d later. These two distinct amnesic effects are abolished if protein degradation by proteasomes is inhibited concomitantly. These results indicate that spatial memory reconsolidation depends on the functionality of L-VDCC in dorsal CA1, that maintenance of subsequent reconsolidated memory trace depends on CaMKII, and these results also suggest that the role played by both L-VDCC and CaMKII is to promote the retrieval-dependent, synaptically localized enhancement of protein synthesis necessary to counteract a retrieval-dependent, synaptic-localized enhancement of protein degradation, which has been described as underlying the characteristic labilization of the memory trace triggered by retrieval. Thus, conceivably, L-VDCC and CaMKII would enhance activity-dependent localized protein renewal, which may account for the improvement of the long-term efficiency of the synapses responsible for the maintenance of reactivated long-term spatial memory.
authors.affiliation: Centro de Memória, Instituto do Cérebro, Pontifícia Universidade Católica do Rio Grande do Sul, RS90610-000 Porto Alegre, Brazil. wwwclaudion@gmail.com
authors.forename: Weber Cláudio
authors.initials: WC
authors.lastname: Da Silva
authors.forename: Gabriela
authors.initials: G
authors.lastname: Cardoso
authors.forename: Juliana Sartori
authors.initials: JS
authors.lastname: Bonini
authors.forename: Fernando
authors.initials: F
authors.lastname: Benetti
authors.forename: Ivan
authors.initials: I
authors.lastname: Izquierdo
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism*; D006624:Hippocampus / Q000502:physiology*; D017774:Long-Term Potentiation / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D057567:Memory, Long-Term / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D015220:Calcium Channels; D009419:Nerve Tissue Proteins; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2