Temporal Event Association and Output-Dependent Learning: A Proposed Scheme of Neural Molecular Connections
Yukifumi Shigematsu*, Hiroshi Okamoto**, Kazuhisa Ichikawa** and Gen Matsumoto***
*Faculty of Egineering, Ehime University
3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
**Corporate Research Centre, Fuji Xerox Co., Ltd. 430 Sakai Nakai-machi, Kanagawa 259-0157 Japan
***Brainway Group, Brain Science Institute, RIKEN 2-1 Hirosawa Wako, Saitama 351-0198, Japan
We introduce a model of temporal-event-associated and output-dependent learning rule, genetically acquired and expressed in a single neuron. This is essentially indispensable for the brain to acquire algorithms, how to process its self-selected information, by itself. This proposed learning rule is revised-Hebbian with a synaptic history trace to correlate one temporal event to others. Temporal events are memorized to be expressed at the synaptic site of inputs and in the form of the asymmetric neural strength corrections associated with temporal events. This learning algorithm has an advantage to associate one temporal event with others, resulting in the neuron with predictability but also makes recalling flexible. Re ’ calling is, according to this learning, independent of timing, supposed to be crucial in learning. Underlying molecular mechanisms for our proposed learning rule are discussed and we identify three important factors: 1) the back-propagating action potentials experimentally observed a single neuron play a crucial role for outputdependent learning, 2) temporally associated, nonlinear couplings are modeled at molecular levels with glutamate receptors, voltage-dependent channels, intracellular calcium concentration, protein kinases and phosphatase, and 3) intracellular concentration of inositol-tri-phosphate [IP3] is the memory substrate of synaptic history.