Description: Dissociated neuronal cell cultures grown on substrate integrated microelectrode arrays (MEAs) generate spontaneous activity that can be recorded for up to several weeks. The signature wave shapes from extracellular recording of neuronal activity display a great variety of shapes with triphasic signals predominating. I characterized extracellular recordings from over 600 neuronal signals. I have preformed a categorical study by dividing wave shapes into two major classes: (type 1) signals in which the large positive peak follows the negative spike, and (type 2) signals in which the large positive peak precedes the negative spike. The former are hypothesized to be active signal propagation that can occur in the axon and possibly in soma or dendrites. The latter are hypothesized to be passive which is generally secluded to soma or dendrites. In order to verify these hypotheses, I pharmacologically targeted ion channels with tetrodotoxin (TTX), tetraethylammonium (TEA), 4-aminopyridine (4-AP), and monensin.
Date: May 2005
Creator: Schwartz, Jacob C.