Hippocampal place fields require direct experience
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Date
2010-12
Authors
Rowland, David Clayton, 1981-
Journal Title
Journal ISSN
Volume Title
Publisher
University of Oregon
Abstract
In humans and other mammals the hippocampus is critical for episodic memories, or memories of events that happen in a particular place and at a particular time. When one records from hippocampal pyramidal neurons in awake, behaving rodents, however, the most obvious firing correlate of these neurons is the animal's position within the environment, earning them the name "place cells". Their aggregate activity is thought to provide the animal with a "cognitive map": a map-like neural representation of the external world used to solve spatial problems. Since rats' ability to take shortcuts through novel space was the major evidence leading Edward Tolman to propose the concept of a cognitive map, it follows that place cells should exist for parts of the environment that the animal has not directly-experienced. We therefore compared the relative stability of place cells recorded from rats in observed versus directly explored parts of an environment in response to a pharmacological manipulation that preferentially destabilizes newly-generated place fields. In contrast to the classical cognitive map hypothesis, the formation of stable place fields clearly requires direct experience with a space, suggesting place cells are part of an autobiographical record of events and their spatial context rather than a map-like representation of space automatically calculated from observed environmental geometry.
This dissertation includes previously unpublished co-authored material.
Description
xi, 64 p. : ill. (some col.)
Keywords
Electrophysiology, Hippocampus, Learning, Memory, Navigation, Neurosciences