Optogenetic investigation of hippocampal ripples influence on prefrontal circuits during contextual fear memory formation

• Grant number: 15/25275-8
• Support type: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): May 01, 2016
• Effective date (End): November 30, 2016
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal researcher: João Pereira Leite
• Grantee: Cleiton Lopes Aguiar
• Supervisor abroad: Kamran Diba
• Home Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Research place: University of Wisconsin-Milwaukee (UW-Milwaukee), United States
• Associated to the scholarship: 14/18211-0 - Characterization and optogenetic control of the hippocampus-medial prefrontal cortex interplay during the post-learning sleep in an experimental model of early-life seizures, BP.PD

Abstract

How do memories persist? Network activity during sleep is thought to support memory through a process known as systems consolidation. In this process, neuronal circuits are reorganized, and new cell assemblies are bound with neurons that were previously activated during acquisition of the memory itself. In particular, reorganization between the hippocampus and the medial prefrontal cortex (mPFC) is considered to play a critical role. These regions are activated during working memory components of behavior and later reactivate in synchrony during sleep. Sharp-wave ripples (SWR), oscillations in the local field of electrodes at the CA1 pyramidal hippocampal layer, seems to provide effective windows for the propagation of information out of the hippocampus and can affect activity throughout the neocortex. Importantly, we hypothesize that this activity provides a mechanism for the systems consolidation of memory. Using large-scale neurophysiological recordings, state-of-the-art mathematical analyses, and optogenetics technology in freely-moving animals, we will test whether hippocampal SWR activity can drive changes in the connectivity of mPFC local circuits. A closed-loop strategy will be implemented and validated to examine directly the role of the hippocampal-prefrontal communication on contextual fear memory consolidation. Optogenetic silencing of prefrontal cortex neurons will subsequently be performed upon the onset of SWRs during post-learning sleep, to test the causal outcome of this activity. We anticipate this work will provide a major advance in our understanding of hippocampal-neocortical information transfer and memory formation during sleep. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ESTEVES, I. M.; LOPES-AGUIAR, C.; ROSSIGNOLI, M. T.; RUGGIERO, R. N.; BROGGINI, A. C. S.; BUENO-JUNIOR, L. S.; KANDRATAVICIUS, L.; MONTEIRO, M. R.; ROMCY-PEREIRA, R. N.; LEITE, J. P. CHRONIC NICOTINE ATTENUATES BEHAVIORAL AND SYNAPTIC PLASTICITY IMPAIRMENTS IN A STREPTOZOTOCIN MODEL OF ALZHEIMER'S DISEASE. Neuroscience, v. 353, p. 87-97, JUN 14 2017. Web of Science Citations: 6.

MASINI, D.; LOPES-AGUIAR, C.; BONITO-OLIVA, A.; PAPADIA, D.; ANDERSSON, R.; FISAHN, A.; FISONE, G. The histamine H3 receptor antagonist thioperamide rescues circadian rhythm and memory function in experimental parkinsonism. TRANSLATIONAL PSYCHIATRY, v. 7, APR 11 2017. Web of Science Citations: 9.