Persistence, reticence, and opportunism of place-field activity in hippocampal neurons

The results indicate that place fields respond in ways similar to the animal’s behavior in processing information from the environment, and the system appears to be well designed to serve as a cognitive map.

Abstract

The experiments described here were done to determine if the nature of hippocampal place-cell activity is consistent with O’Keefe and NadeFs theory that the hippocampus serves as a cognitive map. The results indicate that place fields respond in ways similar to the animal’s behavior in processing information from the environment. Both place fields and behavior are determined more by extramaze than by intramaze cues on the elevated radial-arm maze. The fields are opportunistic in selecting any information available to the organism. Like the behavior, the place-field activity is disrupted by lesions of hippocampal connections. The place-field activity is apparently so specific that the cells are virtually silent in most environments. Finally, the place fields are extremely stable for periods of time approaching the life of the organism in stable environments. Thus, the system appears to be well designed to serve as a cognitive map.