Parsing the hypophagic and anxiogenic effects of cocaine in male and female rats.

Cocaine produces effects including euphoria, local anesthesia, hypophagia/anorexia, and anxiogenesis. The novelty-suppressed feeding (NSF) task is often used as a measure of anxiety-like behavior, except that this task is sensitive to changes in hunger state. First, we determined whether cocaine impacts behavior in the NSF task in male and female Long-Evans rats. Then, to determine whether cocaine-induced alterations in NSF behaviors are due to changes in motivated feeding, we measured the effects of cocaine on operant responding maintained by sucrose. Our results indicate that cocaine administration reduces sucrose consumption in a novel context in a manner indicative of anxiety-like states but does not impact the reinforcing efficacy of sucrose measured by operant responding under a progressive ratio schedule. These results indicate that cocaine's anxiogenic properties play a greater role than its hypophagic properties in its effect on NSF behaviors.