Neural responses to bitter and other stimuli.

<p>Heatmaps showing the net 5 s response to each of 26 taste stimuli (abscissae) across all 36 C3 (<b>A</b>) and 43 C3.SW (<b>B</b>) neurons (ordinates). The heat scale in panel <b>A</b> gives response spike density for panels <b>A</b> and <b>B</b>. Neurons are sorted within mouse line by cluster analysis of activity to all concentrations of quinine, denatonium, cycloheximide, sucrose octaacetate, and propylthiouracil. Pairs of arrowheads of the same color along the base of each dendrogram highlight neurons that were recorded from one mouse and showed differential sensitivity to bitter stimuli (e.g., cells marked by green arrowheads were recorded from one mouse; pair in black from another, etc.). Orange arrowheads along the base of the dendrogram in panel <b>B</b> denote response data from five neurons recorded in series from one C3.SW mouse. Numbers on dendrograms mark neural clusters determined by “scree” plots. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041597#pone-0041597-t001" target="_blank">Table 1</a> gives stimulus abbreviations. Numbers above abbreviations for bitter stimuli indicate concentrations from lowest (e.g., 1) to highest (e.g., 5), as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041597#pone-0041597-t001" target="_blank">Table 1</a>. Plots of average activity in each cluster are given below dendrograms; numbers color-matched to each plot indicate cluster(s).