the Mogil study compared with the Memphis hot plate data. This is likely due to the 54°C that was employed in both the ORNL hot plate study and the Mogil study. The range of values obtained at ORNL and Memphis was lower than those of the other testing laboratories, which produced some range restriction in the observed correlation coefficients. This may be due to more consistent laboratory environmental conditions in these assays or to experimenter effects on stress-induced analgesia, both of which have been previously reported to influence thermal nociception (Chesler et al. 2002a,b;). These correlations are lower than the inter-laboratory correlations than those reported by Wahlsten et al. (2006). This may be due to the limited genetic variability in the BXD RI panel relative to a survey of the common inbred strains, but could also be due to the lower heritability of hot plate measures relative to other measures for which this type of analysis has been performed.
