Framework for Memory:

James J. Knierim, Ph.D., assistant professor of neurobiology and anatomy, Medical School and GSBS

The main character in the movie “Memento” lived entirely in the moment, unable to create new, long-term memories. This type of amnesia, sometimes shared by people with stroke or Alzheimer’s disease, is caused by damage to a part of the brain called the hippocampus.

James J. Knierim, Ph.D.

By studying the hippocampus, Knierim attempts to understand the brain mechanisms involved in learning and memory and in high-level cognition, or the process of knowing. The research group records the activity of hippocampal neurons while rats perform various spatial tasks – hippocampal damage in rats causes deficits in spatial memory, similar to the spatial memory loss of an early Alzheimer’s patient.

“Neurons in the rat hippocampus are selectively active when the rat occupies specific locations in its environment,” Knierim said, “and it is thought that these cells form the basis of the rat’s mental image, or ‘cognitive map,’ of its environment. Recent results from another laboratory have shown that the human hippocampus also contains these types of cells. We try to understand how the brain constructs this cognitive map, and how it is used to underlie spatial memory in the rat and serve as the organizing framework for explicit, conscious memory in humans.”

As a graduate student, Knierim already was interested in learning and memory and how the brain creates mental representations of the external world. “Then I heard a talk on the ‘place cells’ of the hippocampus and was so fascinated by the subject that I decided to do my postdoctoral training in that field,” he said. “I then continued this work when I set up my own lab at UT.”