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. Author manuscript; available in PMC: 2018 Apr 14.
Published in final edited form as: Behav Brain Res. 2017 Jan 29;323:111–116. doi: 10.1016/j.bbr.2017.01.039

Figure 1. VTA atropine decreases VTA morphine-induced locomotion while RMTg atropine increases RMTg morphine-induced locomotion.

Figure 1

A. Bilateral VTA injection sites (n =7). B. Representative image of a cresyl violet- stained section showing VTA injection sites. C. VTA morphine (MOR) increased total locomotion (3 hr) relative to VTA saline (SAL). VTA co-infusion of 3µg atropine (ATR & MOR) reduced VTA morphine-induced locomotion to saline levels. VTA infusion of atropine alone (ATR) had no significant effect on locomotion (n =7; * p < 0.05; ** p < 0.01). D. Locomotion time course: VTA morphine increased locomotion relative to VTA saline between 20 and 110 minutes (* p’s between < .00001 and < .01). VTA co-infusion of 3µg atropine reduced VTA morphine-induced locomotion to saline levels throughout the 3-hr testing period ($ p’s between < 0.0001 and < 0.05 [Atropine & Morphine vs. Morphine]). VTA atropine alone increased locomotion relative to VTA saline between 30–60 min (# p’s between < 0.0001 and < 0.05). E. Bilateral RMTg injection sites (n = 6; stars) and injections sites that were medial or dorsal to the RMTg (n = 4; X symbol; morphine infusion into these sites did not induce locomotion and atropine by itself or co- infused with morphine also was without any effect). F. Representative image of a cresyl violet-stained section showing RMTg injection sites. G. RMTg morphine (MOR) increased total locomotion (3 hr) relative to RMTg saline (SAL). RMTg co-infusion of 3 µg atropine (ATR & MOR) increased RMTg morphine-induced locomotion relative to RMTg morphine alone (MOR). RMTg infusion with atropine alone (ATR) had no significant effect on locomotion (n = 6; * p < 0.05; ** p < 0.01). H. Locomotion time course: RMTg morphine increased locomotion relative to RMTg saline between 10 and 90 minutes (* p’s between < 0.000001 and < 0.01). RMTg co-infusion of 3 µg atropine increased RMTg morphine-induced locomotion ($ p’s between < 0.000001 and < 0.01 [Atropine & Morphine vs. Morphine]). RMTg atropine alone increased locomotion relative to RMTg saline in the first 10 min (# p < .00001). All error bars represent ±SEM.