Alternating dominance of NMDA and AMPA for learning and recall: a computer model.
Physiological studies reveal a dichotomy in biological Hebbian learning: NMDA receptors are utilized for induction of long term potentiation (LTP) whereas AMPA is used for LTP expression. We propose that this dichotomy would have functional value: preventing previously stored memories from interfering with the storage of new memories. A previous hypothesis reduces this interference by temporarily reducing associative weights during learning. Complementary to this model, we propose a dual transmission algorithm in which one set of synaptic weights are used primarily for learning and another primarily for recall. This algorithm shows good performance in a simple neural network model. Biologically, the model could be mediated by a cholinergic switch from dominance of learning-insensitive NMDA receptors to dominance of learning-modifiable AMPA receptors.
Chover
J
J
Departments of Mathematics, University of Wisconsin, USA.
Haberly
L B
LB
Lytton
W W
WW
D000109:Acetylcholine / Q000502:physiology; D000465:Algorithms; D003198:Computer Simulation; D017774:Long-Term Potentiation / Q000502:physiology; D011939:Mental Recall / Q000502:physiology*; D016571:Neural Networks, Computer; D018091:Receptors, AMPA / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*
D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D000109:Acetylcholine