Comment on "Molecular and neural basis of contagious itch behavior in mice"

Abstract

Yu et al (Reports, 10 March 2017, p. 1072) state that contagious itch occurs in mice based on imitative scratching in normal mice observing excessive scratching in genetically modified demonstrator mice. However, despite employing multiple behavioral analysis approaches, we were unable to extend these findings to normal mice observing the well-established histamine model of acute itch in demonstrator mice.

Fig. 1.

Three methods of assessing contagious itch in mice.

Fig. 2.. No evidence for contagious itch in mice.

(A to C) In no case was scratching behavior in uninjected mice observing histamine-injected demonstrators significantly greater than that of uninjected mice observing uninjected demonstrators, indicating that contagious itch does not appear to occur in mice. Chi-square analysis was used for imitative (A) and temporally contiguous (B) scratching, whereas the Kruskal-Wallis H test was used to compare the three uninjected conditions in (C). P < 0.05 was considered significant in all cases. n/s, nonsignificant comparisons.