Stimulus control of cocaine self-administration

Area of Science:

• Behavioral neuroscience
• Addiction research
• Psychopharmacology

Background:

• Environmental stimuli associated with drug acquisition can elicit drug-related behaviors.
• Understanding stimulus control is crucial for addressing human drug abuse.
• Previous research has primarily focused on food-maintained responding.

Purpose of the Study:

• To establish stimulus control over cocaine self-administration in laboratory animals.
• To investigate the efficacy of multicomponent operant schedules for cocaine intake.
• To compare stimulus control mechanisms between drug and food reinforcement.

Main Methods:

• Utilized multiple and chained schedules with short, alternating components (variable-interval, differential-reinforcement-of-other-behavior, extinction).
• Adjusted schedule parameters and cocaine dose per rat to achieve stable responding.
• Analyzed whole-body drug levels and intake rates to assess drug exposure.

Main Results:

• Successfully generated stimulus control of cocaine self-administration for the first time using these schedules.
• Rats maintained stable drug levels (2.3–3.4 mg/kg) and intake rates (~6.0 mg/kg/hr).
• Stimulus control patterns were comparable to those observed with food reinforcement.

Conclusions:

• Multicomponent operant schedules effectively establish stimulus control over cocaine self-administration.
• The findings suggest shared neurobiological mechanisms underlying cocaine and food reinforcement.
• This model provides a valuable tool for studying environmental influences on drug-seeking behavior.