Following the completion of each experiment, successful targeting of the lateral ventricles was confirmed by infusing 0.6% cresyl violet. Animal were injected with 100mg sodium pentobarbital (Sigma Aldrich, St. Louis, MO). The OMP animals had the tubing connecting the OMP to the cannula exposed and 2 μl of cresyl violet was infused over 60 s, whereas the animals in Condition 3 had 1 μl/side of cresyl violet infused over 60 s. Subsequently, the animal's brains were removed and the presence of cresyl violet in the ventricles was confirmed. Those animals that did not display ventricular cresyl violet were not included in the statistical analysis.
