The role of the hippocampus and post-learning hippocampal activity in long-term consolidation of context memory

Sutherland, Sparks and Lehmann (2010) proposed a new theory of memory consolidation, termed Distributed Reinstatement Theory (DRT), where the hippocampus (HPC) is needed for initial encoding but some types of memories are established in non-HPC systems through post-learning HPC activity. An evaluation of the current methodology of temporary inactivation was conducted experimentally. By permanently implanting two bilateral guide cannulae in the HPC and infusing ropivacaine cellular activity could be reduced by 97%. Rats were trained in a context-fear paradigm. Six learning episodes distributed across three days made the memory resistant to HPC inactivation while three episodes did not. Blocking post-learning HPC activity following three of six training sessions failed to reduce the rat’s memory of the fearful context. These results fail to support DRT and indicate that one or more memory systems outside the HPC can acquire context memory without HPC post-event activity.

Authors

• Gulbrandsen-MacDonald, Tine L
• University of Lethbridge. Faculty of Arts and Science

• Hippocampus (Brain) -- Physiology
• Hippocampus (Brain) -- Research
• Memory -- Research
• Memory -- Physiological aspects
• Memory disorders
• Brain -- Localization of functions
• Rats as laboratory animals
• Dissertations, Academic

Identifier

hdl:10133/2635

OAI identifier oai:identifier

oai:opus.uleth.ca:10133/2635