Place cells are nerve cells, or neurons, located in the hippocampus, a seahorse-shaped structure in the center of the brain that plays a major role in spatial navigation and memory. These neurons fire at a high rate when an animal occupies a part of an environment corresponding to the cell's "place field." Different cells respond to different locations in the environment. In his 1971 paper with Jonathan Dostrovsky, O'Keefe first described the existence of place cells and first suggested the hypothesis that place cells might form the basis of a cognitive map of the environment.
In their experiments, O'Keefe and his colleagues have found that the mapping system creates the sense of place by integrating information from different environmental landmarks such as walls and corners together with information from the animal's own movements as it navigates around the environment. Knowing how far the animal has moved in a particular direction allows the hippocampus to keep track of an animal's position even in the dark.
Work in many laboratories around the world has revealed the existence of other types of spatial cells including ones coding for direction and distance, has identified some of the environmental cues used by place cells, and has begun to uncover aspects of the synaptic plasticity and cellular pathways which enable the hippocampus to remember places in the environment. O'Keefe's own lab has identified both short-term and long-term memory properties of these cells.
MEDICA.de; Source: Robin Leedy & Associates, Inc.