Influences of laboratory environment on behavior (2002)

Chesler, E. J., Wilson, S. G., Lariviere, W. R. et al.

Abstract

Experimenter identity had the greatest association with tail-withdrawal latency. ... Precisely what differentiated experimenters in the present study remains uncertain. Experimenter age, sex and experience level did not correlate with the observed differences. All experimenters were trained by the principal investigator or by a graduate student trained directly by him. Differential animal handling, perhaps inducing stress differences, is likely to be responsible. Large projects are often carried out by multiple undergraduate and graduate students, postdocs, technicians and other transient personnel. .. Also varying with behavior were environmental factors not commonly appreciated as affecting pain sensitivity, including season, cage density, time of day (within a 12 h diurnal period), humidity and testing order.The order in which mice were caught from cages was related to their pain response in a subsequent tail-flick test.