1. Academic Validation
  2. CaMKII requirement for the persistence of in vivo hippocampal mossy fiber synaptic plasticity and structural reorganization

CaMKII requirement for the persistence of in vivo hippocampal mossy fiber synaptic plasticity and structural reorganization

  • Neurobiol Learn Mem. 2017 Mar:139:56-62. doi: 10.1016/j.nlm.2016.12.015.
Yectivani Juárez-Muñoz 1 Alejandro Rivera-Olvera 1 Laura E Ramos-Languren 1 Martha L Escobar 2
Affiliations

Affiliations

  • 1 División de Investigación y Estudios de Posgrado, Facultad de Psicología, Universidad Nacional Autónoma de México, 04510 México, Mexico.
  • 2 División de Investigación y Estudios de Posgrado, Facultad de Psicología, Universidad Nacional Autónoma de México, 04510 México, Mexico. Electronic address: mescobar@unam.mx.
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.

Keywords

CaMKII; LTP; Memory persistence; Mossy fiber; Synaptogenesis.

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