Cellular Basis of Learning in the Mammalian Cortex: Role of Postsynaptic Glutamate Receptors

University Of Maryland, College Park, College Park MD

Investigators

Abstract

The ability of the nervous system to learn and remember ultimately depends on the changes in the strength of synapses, the points of contact between individual nerve cells. The majority of research on memory formation has focused on early time points during the encoding of a memory, when the change in synaptic strength is first induced. Therefore, little is known about the mechanisms by which memories are retained over the lifetime of an organism. This obstacle can be overcome by using a multi-disciplinary approach to studying the molecular basis of olfactory discrimination learning in rodents. Olfaction is the primary sensory modality in the rat, and rats quickly learn to associate odor with reward. Olfactory discrimination is a robust animal learning paradigm that results in activation of a large population of synapses in the piriform cortex, thereby offering an invaluable opportunity to combine behavioral, electrophysiological and biochemical methods to study the cellular mechanisms of learning. Olfactory discrimniation learning will be used to test the hypothesis that synapses in the piriform cortex become less "plastic" after learning. The proposed experiments merge the research efforts of two laboratories in very different geographical/political environments. It is predicted that the data gleaned from these experiments have a wide readership, and will help to build bridges between the fields of behavioral neuroscience, synaptic physiology, molecular and cell biology. In addition it will focus research attention on a very important aspect of memory processes, memory retention, which has been previously ignored.