Work in the previous support period led to a finding that electrical stimulation of the medial temporal lobe of monkeys during the delay period of a delayed matching-to-sample task was highly disruptive of performance if only a few images were repeatedly reused. The identical stimulation was only mildly disruptive if fresh images were used for each trial. In memory tasks with human subject, the use of repeated images leads to a strategy of active rehearsal during the delay period. In monkeys, the use of repeated images is a key to inducing the so- called delay activity. This is an elevated discharge rate in neurons usually lasting throughout the delay period, with different neurons selectively active for different stimuli. Thus, the activity across the population of neurons encodes a memory of that which is to-be- remembered. The delay activity appears like a neuronal version of continuous rehearsal, and is an excellent candidate for the neural embodiment of memory during the delay under these conditions. The fascination with this delay activity is that it may be our best model for the everyday human working memory which is the substrate for thought. The evidence that delay activity is the holder of the memory is, however, indirect. The purpose of the current proposal is to test that hypothesis directly. This will be done by using electrical stimulation which is known to disrupt that delay activity (see Preliminary Studies). If delay activity of neurons is the carrier of the memory then disruption of the delay activity should disrupt the behavioral memory. The contribution of this project is aimed directly at a prominent candidate neuronal mechanism of memory. Its clinical relevance is not immediate but could nonetheless be profound since a full understanding of the mnemonic circuitry should have a major impact on the important - and with the aging population - growing health problems involving memory.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS024217-12
Application #
2891692
Study Section
Special Emphasis Panel (ZRG2-BPO (01))
Program Officer
Edwards, Emmeline
Project Start
1997-07-01
Project End
2001-05-31
Budget Start
1999-06-01
Budget End
2000-05-31
Support Year
12
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Rochester
Department
Neurosciences
Type
Schools of Dentistry
DUNS #
208469486
City
Rochester
State
NY
Country
United States
Zip Code
14627