TY - JOUR
T1 - The effects of medial prefrontal cortex infusions of cocaine in a runway model of drug self-administration
T2 - Evidence of reinforcing but not anxiogenic actions
AU - Guzman, Daniel
AU - Moscarello, Justin M.
AU - Ettenberg, Aaron
N1 - Funding Information:
The authors acknowledge with thanks the assistance of our laboratory technician, Eric Posthumus, in testing the animals and the advice and guidance of Dr. Osnat Ben-Shahar throughout the project. This work was supported by NIH grant DA05041 awarded to AE through the National Institute of Drug Abuse.
PY - 2009/3/1
Y1 - 2009/3/1
N2 - In previous work we have shown that rats running a straight alley for intravenous (i.v.) or intracerebroventricular (i.c.v.) injections of cocaine develop an ambivalence about entering the goal box that results from cocaine's mixed reinforcing and anxiogenic properties. What remains unclear is whether or not cocaine's opposing properties stem from actions on a common neuronal system or from dual actions on separate systems - one related to reward and another to anxiogenic responses. One way to address this question is to deliver cocaine into discrete brain areas as a means of assessing whether or not the positive and negative effects of the drug can be spatially dissociated. Given the putative role of mesocorticolimbic dopamine pathways in the mediation of cocaine-reinforced behavior, the current study examined the cocaine-seeking behavior of rats permitted to run an alley once each day for bilateral medial prefrontal cortex microinjections of cocaine (0.0, 12.5, 25 or 50 μg/0.5 μl per side) delivered upon goal-box entry. The results demonstrated that undrugged animals are highly motivated to seek medial prefrontal cortex cocaine without any evidence of negative or anxiogenic effects at any dose. These results are therefore consistent with suggestions of a medial prefrontal cortex involvement in the reinforcing actions of cocaine, and indicate that the dual and opposing actions of the drug can be dissociated and hence may be mediated by the drug's actions on separate neuronal systems.
AB - In previous work we have shown that rats running a straight alley for intravenous (i.v.) or intracerebroventricular (i.c.v.) injections of cocaine develop an ambivalence about entering the goal box that results from cocaine's mixed reinforcing and anxiogenic properties. What remains unclear is whether or not cocaine's opposing properties stem from actions on a common neuronal system or from dual actions on separate systems - one related to reward and another to anxiogenic responses. One way to address this question is to deliver cocaine into discrete brain areas as a means of assessing whether or not the positive and negative effects of the drug can be spatially dissociated. Given the putative role of mesocorticolimbic dopamine pathways in the mediation of cocaine-reinforced behavior, the current study examined the cocaine-seeking behavior of rats permitted to run an alley once each day for bilateral medial prefrontal cortex microinjections of cocaine (0.0, 12.5, 25 or 50 μg/0.5 μl per side) delivered upon goal-box entry. The results demonstrated that undrugged animals are highly motivated to seek medial prefrontal cortex cocaine without any evidence of negative or anxiogenic effects at any dose. These results are therefore consistent with suggestions of a medial prefrontal cortex involvement in the reinforcing actions of cocaine, and indicate that the dual and opposing actions of the drug can be dissociated and hence may be mediated by the drug's actions on separate neuronal systems.
KW - Drug reward
KW - Intracranial self-administration
KW - Operant behavior
KW - Opponent process
KW - Runway
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U2 - 10.1016/j.ejphar.2009.01.003
DO - 10.1016/j.ejphar.2009.01.003
M3 - Article
C2 - 19171134
AN - SCOPUS:60349115002
SN - 0014-2999
VL - 605
SP - 117
EP - 122
JO - European Journal of Pharmacology
JF - European Journal of Pharmacology
IS - 1-3
ER -