title: CaMKII requirement for the persistence of in vivo hippocampal mossy fiber synaptic plasticity and structural reorganization.
abstract: CaMKII has been proposed as a molecular substrate for long-term memory storage due to its capacity to maintain an active autophosporylated state even after the decay of the external stimuli. The hippocampal mossy fiber-CA3 pathway (MF-CA3) is considered as a relevant area for acquisition and storage of different learning tasks. MF-CA3 pathway exhibits a form of LTP characterized by a slow initial increase in the EPSP slope that is independent of NMDA receptors activation. Our previous studies show that application of high frequency stimulation sufficient to elicit MF-CA3 LTP produces structural reorganization, in a manner independent of LTP induction, at the stratum oriens of hippocampal CA3 area 7days after stimulation. However, the molecular mechanisms that underlie the maintenance of MF-CA3 LTP as well as the concomitant structural reorganization in this area remain to be elucidated. Here we show that acute microinfusion of myr-CaMKIINtide, a noncompetitive inhibitor of CaMKII, in the hippocampal CA3 area of adult rats during the late-phase of in vivo MF-CA3 LTP blocked its maintenance and prevented the accompanying morphological reorganization in CA3 area. These findings support the idea that CaMKII is a key molecular substrate for the long-term hippocampal synaptic plasticity maintenance.
authors.affiliation: División de Investigación y Estudios de Posgrado, Facultad de Psicología, Universidad Nacional Autónoma de México, 04510 México, Mexico.
authors.forename: Yectivani
authors.initials: Y
authors.lastname: Juárez-Muñoz
authors.affiliation: División de Investigación y Estudios de Posgrado, Facultad de Psicología, Universidad Nacional Autónoma de México, 04510 México, Mexico.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Rivera-Olvera
authors.affiliation: División de Investigación y Estudios de Posgrado, Facultad de Psicología, Universidad Nacional Autónoma de México, 04510 México, Mexico.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Ramos-Languren
authors.affiliation: División de Investigación y Estudios de Posgrado, Facultad de Psicología, Universidad Nacional Autónoma de México, 04510 México, Mexico. Electronic address: mescobar@unam.mx.
authors.forename: Martha L
authors.initials: ML
authors.lastname: Escobar
mesh_terms: D000818:Animals; D056654:CA3 Region, Hippocampal / Q000187:drug effects / Q000378:metabolism*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008297:Male; D019599:Mossy Fibers, Hippocampal / Q000187:drug effects / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004791:Enzyme Inhibitors; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2
keywords: CaMKII; LTP; Memory persistence; Mossy fiber; Synaptogenesis