ABSTRACT
Rodent hippocampus is known to represent spatial maps of environments. Hippocampal
pyramidal cells called place cells each fire when the animal is located in a particular
spatial domain, called a place field of the place cell. The system of place fields forms a
cognitive map of an environment. Although cognitive maps are believed to play a critical
role in navigation and in formation of episodic memories, many questions about place
fields remain unanswered. What are the general principles of place field formation? Why
do they come in various shapes and sizes and typically have broad tails? How can a
cognitive map be used for navigation, if its activity (e.g., during maze running) only
provides information about the current location? Alternatively, what exactly do place
fields encode? Previously proposed theoretical frameworks, including local view models
(O’Keefe & Burgess, 1996), path integration models (Redish & Touretzky, 1997),
trajectory learning models (Bloom & Abbott, 1996) and combinations of the above, do
not suggest unambiguous and general answers.
