Hippocampal Representation of Space in Birds: An Electrophysiological Analysis

Bowling Green State University, Bowling Green OH

Investigators

Abstract

Vertebrate animals, including man, are able to experience past events in their lives as memory because the nerve cells of the brain are able to create a physical record of those past events. A large body of experimental research has identified one brain structure, the hippocampus, as being critically important for the formation of new memories. However, how the physiological activity of nerve cells in the hippocampus are able to contribute to the physical record of past events we call memory remains uncertain. The problem to be studied in the proposed research exploits the remarkable spatial memory ability of homing pigeons and the important role of the hippocampus in that spatial memory. Electrodes, which permit the recording of activity from single nerve cells, will be surgically implanted in the hippocampus of homing pigeons. The electrodes will be used to observe how nerve cell activity changes as a consequence of exploration and the formation of new memory in pigeons allowed to freely move in an open environment. Changes in nerve cell activity as a consequence of behavior and memory would provide important information on how the hippocampus creates a physical record of past events. How the brain creates a physical record of past experiences is one critical dimension that contributes to the uniqueness of each individual. This is apparent and tragically evident in people who suffer memory loss as a consequence of brain disease, brain trauma or just aging, and gradually or quickly experience a loss of identity. Basic research using animal models is a fundamental part of unraveling the mystery of how the brain creates memories and what goes wrong when an unhealthy brain loses its ability to create new memories. By studying how activity in the nerve cells of the bird hippocampus participates in memory formation, valuable insight may be gained regarding the relationship between the hippocampus, including the human hippocampus, and memory, and help in understanding how dysfunction in the hippocampus can lead to memory loss.