  Recent investigations of traumatic brain injuries have shown that these
injuries can result in conformational changes at the level of individual
neurons in the cerebral cortex. Focal axonal swelling is one consequence of
such injuries and leads to a variable width along the cell axon. Simulations of
the electrical properties of axons impacted in such a way show that this damage
may have a nonlinear deleterious effect on spike-encoded signal transmission.
The computational cost of these simulations complicates the investigation of
the effects of such damage at a network level. We have developed an efficient
algorithm that faithfully reproduces the spike train filtering properties seen
in physical simulations. We use this algorithm to explore the impact of focal
axonal swelling on small networks of integrate and fire neurons. We explore
also the effects of architecture modifications to networks impacted in this
manner. In all tested networks, our results indicate that the addition of
presynaptic inhibitory neurons either increases or leaves unchanged the
fidelity of the network's processing properties with respect to this damage.
