SPATIAL MEMORY · Characterization of the spatial and mnemonic functions of the hippocampus in the non-human primate
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2005-10-01 → 2007-09-30
- EU contribution
- €80,000
- Participants
- 1
- Scheme
- IRG
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - SPATIAL MEMORY (Characterization of the spatial and mnemonic functions of the hippocampus in the non-human primate)
Our project aimed at understanding the neural bases of mnemonic and spatial functions of the hippocampus. To this end, we developed behavioural testing approaches which were designed to mimic real life situations and used electrophysiological techniques to study the neural patterns underlying these memories. Our report was articulated over two research lines: 1. the neural correlates underlying visuo-spatial learning in primates including human; 2. the neural correlates of voice-face pair associates in the monkey within the hippocampus. These two projects both aimed at understanding the neural basis of episodic memory, which allowed us to remember events, where they took place, when they occurred and who they involved. Using virtual reality techniques, we studied oscillatory activity in human subjects performing navigational tasks. The results associated with our first project showed larger oscillatory activity before environments became familiar, which suggested a broad recruitment of the population before learning. With learning, oscillatory activity tended to be observed in tighter time periods, which suggested that formed memory was supported with smaller neurones population. Our second project combined single unit recording and behavioural techniques in macaques and aimed at understanding how hippocampal neurones combined multimodal information to represent identity. Using spontaneous recognition techniques we showed that monkeys, like human, oriented towards familiar speakers based on their voice. Single unit recordings showed that the neural response elicited by a face was enhanced if it followed the voice matching it. This suggested a cross-sensory preparedness of the hippocampal neuronal network that conveyed information about identity through multisensory elements.
Data: CORDIS, © European Union
Project objective
Spatial memory is the memory system that allows an individual to answer questions such as: Where am I? Where is it and How do I get there? Hippocampus is critical for spatial memory as its lesion induces profound deficits in spatial learning in human, non-human primates and rats. In the rat, electrophysiological studies show that a large proportion of hippocampal neurons, called place cells, signal the animals' position in the environment. Place cells are thought to constitute the neuronal basis of spatial memory, although only few studies attempted to test this hypothesis directly. In the primate, the lack of studies does not clearly allow to determine how spatial representations are encoded in the hippocampus at the neuronal level.This project aims to bring further our knowledge on the neuronal basis of memory using the closest experimental model to human. I propose a neurophysiological and behavioural approach featuring a virtual reality environment adapted to the monkey that allows studying single cell activity directly as animals form new spatial memories.Specifically this projects aims at addressing 3 questions:1) How is spatial information represented in the primate hippocampus?2) What is the link between the activity of place cells and memory formation,3) What are the physiological and functional properties of hippocampal cells in the primate?To address these questions, I will record the activity of hippocampal neurons as animals navigate in the virtual environment with or without memory demand. In parallel, I will use physiological criteria to characterize the hippocampal neurons and evaluate their functional properties with respect to the task demands. This type of information is critical as to build realistic models of hippocampus that take in account physiological and functional properties of the cells. In the long-term this project will allow to better understanding how hippocampal neurons underlie the formation of new spatial memories.
Original text from CORDIS.
Participants
- CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE · PARISCoordinatorFrance
Links
Data: CORDIS, © European Union