The effect of background noise on the precision of pulse packet propagation in feed-forward networks

Evidence suggests precise spike timing plays a functional role in cortical information processing. However, it is still a matter of debate whether such precision can be achieved in the presence of ongoing synaptic background activity. We investigate this question by modeling a feed-forward network of Hodgkin-Huxley neurons. Extending the basic model, we additionally include variable synaptic delays. We find that suprathreshold waves of synchronous activity propagate through the network reliably and with submillisecond precision. On the other hand, background activity allows slightly subthreshold activity to propagate reliably as well, but not with high temporal precision. (c) 2006 Elsevier B.V. All rights reserved.