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.
Audio for this talk requires sound hardware, and RealPlayer or RealAudio
by RealNetworks.
Begin continuous audio for the whole
talk. (Or, right-click to download the whole audio file.)
To begin viewing slides, click on the first slide below.
Author entry (protected)