Locomotor activity in an open field has been commonly used as a measure for exploration, novelty seeking, anxiety and predisposition to addiction to drugs of abuse. In our study, two laboratories, Memphis (Cocaine) and UTHSC (Ethanol), collected data on open field locomotion following saline in 15 and 20 min on 64 BXD RI strains, respectively. We compared these data with data collected on saline-induced locomotor response by Demarest et al. (1999) on 25 BXD RI strains. Results indicate that there is good correlation among data on saline-induced locomotor response across the three sets (Fig. 5a). Correlations among the rMemphis,UTHSC = 0.556,rMemphis,Demarest = 0.781 and rDemarest,UTHSC = 0.695. These results confirm previous reports that locomotor activity is a highly stable trait and that saline-induced locomotor response is not only robust across laboratories but also across previously published studies.
