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Updated: Jun 22, 2026
A Protocol for Measuring Cue Reactivity in a Rat Model of Cocaine Use Disorder
Published on: June 18, 2018
Effects of self-administered cocaine in adolescent and adult male rats on orbitofrontal cortex-related neurocognitive
Roxann C Harvey1, Kimberly A Dembro, Kiran Rajagopalan
1Laboratory of Behavioral Neuroscience, Department of Psychology, Boston University, 64 Cummington Street, Boston, MA, 02215, USA.
Rationale:
Deficits in amygdala-related stimulus-reward learning are produced following 18 drug-free days of cocaine self-administration or its passive delivery in rats exposed during adulthood. No deficits in stimulus-reward learning are produced by cocaine exposure initiated during adolescence.
Objectives:
To determine if age of initiating cocaine exposure differentially affects behavioral functioning of an additional memory system linked to cocaine addiction, the orbitofrontal cortex.
Materials And Methods:
A yoked-triad design (n = 8) was used. One rat controlled cocaine delivery and the other two passively received cocaine or saline. Rats controlling drug delivery (1.0 mg/kg) self-administered cocaine from either P37-P59 or P77-P99, and then underwent 18 drug-free days (P60-P77 vs. P100-P117). Rats next were tested for acquisition of odor-delayed win-shift behavior conducted over 15 sessions (P78-P96 vs. P118-P136).
Results:
Cocaine self-administration did not differ between adults and adolescents. During the test phase of the odor-delayed win-shift task (relatively difficult task demands), rats from both drug-onset ages showed learning deficits. Rats with cocaine self-administration experience committed more errors and had longer session latencies compared to rats passively receiving saline or cocaine. Rats with adolescent-onset cocaine self-administration experience showed an additional learning deficit by requiring more sessions to reach criterion levels for task acquisition compared to same-aged passive saline controls or rats with adult-onset cocaine self-administration experience. Rats passively receiving cocaine did not differ from the passive saline control from either age group.
Conclusions:
Rats with adolescent-onset cocaine self-administration experience were more impaired in an orbitofrontal cortex-related learning task than rats with adult-onset cocaine self-administration experience.
