Saint Joseph's University
Subject Listing - Biology
Advisor: Dr. James J. Watrous
Friday, Poster Session 5, Presentation Kiosk 12 A, Health & Fitness Center
THE ROLE OF CONDUCTANCE IN LONG-TERM POTENTIATION OF A FIVE CELL NEURONAL NETWORK
Altering the synaptic strength of the signal sent between two neurons causes a change in the transmembrane potential and the action potential that is produced by the postsynaptic cell. An increase in the conductance of the pre-synaptic synapse can result in an over stimulation of the postsynaptic cell causing the cell to stop firing. A decrease in the conductance of the pre-synaptic synapse may cause the postsynaptic cell to never reach its threshold potential. Similarly, in a neuronal network where there is a group of interconnected neurons, an increase or decrease in synaptic conductance of a pre-synaptic cell can cause the entire network to over stimulate and cease activity or cause some neurons to never fire. In order to create a continuous network of neurons, the synapses between cells need to be firing continuously as well. Long-term potentiation (LTP) is the long-lasting increase of strength in the connection between nerve cells. To simulate the role that synaptic conductance plays in long-term potentiation, a five cell Hodgkin-Huxley type network was created interconnected by excitatory chemical synapses, using the computer program, SNNAP(Simulator for Nerve Networks and Action Potentials). An initial stimulus is applied to the first neuronal cell to begin the network. By applying one or more brief, high frequency stimuli to a pre-synaptic cell or by applying a cooperative weaker stimulation to many cells, the cells in the network will continue to fire for an extended period. By altering and observing the changes in the conductance of the synapses, it is possible to simulate long-term potentiation within the network.
Advisor: Dr. James J. Watrous, Professor, Biology, Saint Joseph's University, Philadelphia, PA