The analysis of the action of the anti-influenza and anti-Parkinsonian drug amantadine on current flow through cellular ion channels called NMDA receptors is shown.

The data traces are patch-clamp recordings of current flow through single proteins in the nerve cell membrane. The graphs in B and C show the analysis of the duration of "bursts" that the channels display, with higher concentrations of the drug shortening these bursts substantially. This reveals that the drug both blocks the open channel and interacts with the "gate" that opens and closes the channel; the relation of these two effects is shown in D. The solid line plots are fits of an equation derived from a state model describing such an interaction between a drug and a channel, and the dashed and dotted lines are the predicted relationships based on the model under various conditions. Note that the data point apparently at 0 in C is in fact plotted on the logarithmic axes at X = 1E-4 to allow the break in the axis. An Origin Scale object (XY Scaler) is also included.

The graph was prepared using Origin 6.1 and Origin 7.5 by Thomas A. Blanpied, an Assistant Professor of Physiology at the University of Maryland School of Medicine in Baltimore, MD. He studies nerve cells, their synaptic connections, and the cellular machinery that controls the protein content of the cell membrane and synapses, using electrophysiology and multicolor live-cell confocal microscopy.