Sequence learning in differentially activated dendrites.
Differentially activated areas of a dendrite permit the existence of zones with distinct rates of synaptic modification, and such areas can be individually accessed using a reference signal which localizes synaptic plasticity and memory trace retrieval to certain subregions of the dendrite. It is proposed that the neural machinery required in such a learning/retrieval mechanism could involve the NMDA receptor, in conjunction with the ability of dendrites to maintain differentially activated regions. In particular, it is suggested that such a parcellation of the dendrite allows the neuron to participate in multiple sequences, which can be learned without suffering from the 'wash-out' of synaptic efficacy associated with superimposition of training patterns. This is a biologically plausible solution to the stability-plasticity dilemma of learning in neural networks.
Nielsen
Bjørn Gilbert
BG
Quantum Protein Centre, Physics Institute, Technical University of Denmark, Bygn. 309, Anker Engelundsvej, DK-2800 Lyngby, Denmark. bjorn.nielsen@fysik.dtu.dk
D000818:Animals; D003198:Computer Simulation; D003213:Conditioning, Psychological / Q000502:physiology*; D003712:Dendrites / Q000502:physiology*; D008959:Models, Neurological; D016571:Neural Networks, Computer; D009473:Neuronal Plasticity / Q000502:physiology; D017966:Pyramidal Cells / Q000502:physiology / Q000648:ultrastructure; D013569:Synapses / Q000502:physiology