Schedule Jun 7, 2000
Small Networks of Biological and Electronic Neurons
Dr. Henry Abarbanel, U.C. San Diego
Networks of order ten neurons called Central Pattern Generators (CPG) are responsible for sending rhythmic voltage activity to muscle groups in most animals. We have studies the Pyloric CPG responsible for pumping food from the stomach to the digestive system in lobsters. Our neurophysiological experiements measuring intracellular membrane voltage show that the individual neurons in the CPG are chaotic nonlinear oscillators whose job is to work collectively with the other neurons to provide a regular control function for the pump. Nonlinear time series analysis and biological modeling shows that these individual neurons have three to five active degrees of freedom, and we built a phenomenological model which captures this aspect of neural activity. We have also constructed an analog circuit which integrates the model differential equations and shows the same membrane voltage characterstics of the biological neurons. We have shown that we can remove one of the biological neurons from the CPG and replace it with our analog circuit neuron and repair the damage to the circuit. This neural transplant has interesting potential for new biological investigations, novel neural network applications, and possibly biomedical use.

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