To assess whether bilateral CTAP injection reduced the vigor of behavioral responding, we asked whether the injections affected the animals’ latency to initiate movement after cue onset. (We were unable to determine whether speed of approach to the receptacle was affected because bilateral CTAP injection greatly reduced the likelihood of such a response to the cue.) Only sessions with available video tracking data were used in these analyses, and to boost statistical power, free-fed saline-injected and uninjected sessions were pooled, as rats’ behavior during these sessions was statistically indistinguishable (N = 4 sessions for restricted bilateral; N = 4 sessions for free fed bilateral; N = 9 sessions for free-fed unilateral; N = 7 sessions for free fed saline + uninjected). (A–C) The declines in cue responding in free-fed rats were accompanied by increases in latency to initiate movement, which were observed in the control condition (uninjected and saline injected), bilateral CTAP-injected and unilateral CTAP-injected free-fed rats. In contrast, food-restricted rats exhibited no change in latency to initiate locomotion. A three-factor ANOVA (drug x time x satiety state) revealed significant main effects on latency of time (F1,311 = 45.28, p<0.001) and satiety state (F1,311 = 40.66, p<0.001), but not drug (F1,311 = 0.405, p=0.53). As with response ratio, there was a significant interaction between time x satiety state (F1,311 = 10.77, p<0.01). Latencies to move were greater overall in free-fed than restricted animals; although this result contrasts with the absence of a difference in latency to maximum speed in free-fed vs restricted animals (Figure 2G), the effect in C) is due to inclusion of trials in which animals did not respond (but still eventually moved) as the effect was not observed when we limited the dataset to trials on which the animal responded. Notably, there was a trend towards greater latency after CTAP injection than after either control or unilateral CTAP injection, which was not apparent in the pre-injection window. Thus, although all free-fed groups showed a gradual decline in response ratio that was accompanied by increased latency to initiate movement, only bilateral CTAP injection caused a sharp decline in response ratio, which was observed only in free-fed (and not food-restricted) rats. †, p<0.10; **p<0.01, Wilcoxon, Holm-Sidak corrected. We then asked whether the decline in response ratio observed in bilateral CTAP-injected free-fed rats could have been caused by an overall reduction in locomotor activity, which we assessed by measuring locomotion during the ITI. However, although locomotion was reduced in the post-injection window compared with the pre-injection window in CTAP-injected, saline-injected and non-injected free-fed rats, there was no difference in this measure between CTAP and control (combined saline and non-injected) groups (D). Therefore, the sharp attenuation of cue-responding in bilateral CTAP-injected rats cannot be attributed to a generalized motor impairment. Thick darker lines represent mean ± SEM for each group; thin lighter lines represent individual sessions of bilateral injections (blue) or vehicle + uninjected (gray).