C. Asynchronous background input alone drives a low level of firing even in the absence of any signaling input, as seen by the two spikes that occur in the 1 second sample trace. The peaks of the action potentials have been clipped at 0 mV. Source: Theoretical Approaches to Neuroscience: Examples from Single Neurons to Networks, Principles of Neural Science, Fifth Editon Citation: Kandel ER, Schwartz JH, Jessell TM, Siegelbaum SA, Hudspeth AJ, Mack S. Principles of Neural Science, Fifth Editon; 2012 Available at: http://neurology.mhmedical.com/DownloadImage.aspx?image=/data/books/1049/kan_appf_f001.png&sec=59734212&BookID=1049&ChapterSecID=59138711&imagename= Accessed: October 20, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved