[PAST EVENT] Matt Peppe--Honors Thesis Defense

April 27, 2011
1pm - 2pm
Jones Hall, Room 131
200 Ukrop Way
Williamsburg, VA 23185Map this location
A neuronal network can be represented as a directed graph, with each neuron corresponding to a node and each connection between an axon from one neuron and the dendrite of another corresponding to an edge. We investigated the effects of two statistical properties of directed graphs on the capacity of excitatory and inhibitory neuronal networks to exhibit bistability. One measure is node-degree correlation, the propensity of nodes to have similar in-degrees and out-degrees. The other measure is edge-degree correlation, the propensity of similar in-degrees and out-degrees of connected nodes. By grouping subpopulations of neurons according to their in and out degrees, we performed simulations testing the effect of these different forms of assortativity on network input/output properties. We found that node-degree correlation and edge-degree correlation affect the range of synaptic coupling strengths between neurons and of external stimulation for which there are two steady-state mean firing rates for the neurons in the network. The existence of bistability and hysteresis is important as the physiological basis of short term memory.