Diazepam self-administration and resistance to extinction

Area of Science:

• Pharmacology
• Behavioral Neuroscience

Background:

• Understanding the reinforcing properties of drugs is crucial for addiction research.
• Diazepam, a benzodiazepine, is known for its anxiolytic and sedative effects.
• Assessing drug reinforcement often involves self-administration paradigms.

Purpose of the Study:

• To investigate the self-administration behavior of diazepam in non-human primates.
• To determine the dose-response relationship of diazepam self-administration.
• To examine the influence of prior diazepam exposure on responding during extinction.

Main Methods:

• Monkeys were trained to respond on a lever for diazepam or saline using successive approximation.
• A dose-response function for diazepam was established.
• Saline was substituted for diazepam to assess responding under extinction conditions.
• Prior cocaine self-administration was also studied.

Main Results:

• Diazepam self-administration was maintained at doses of 0.01-0.03 mg/kg/infusion.
• Responding for saline remained high during extinction, even after extended sessions.
• The level of responding during extinction correlated with previous diazepam intake.
• Cocaine self-administration followed by saline substitution led to a decline in responding.

Conclusions:

• Diazepam self-administration can lead to persistent responding for a non-drug reinforcer (saline) during extinction.
• This effect complicates the interpretation of diazepam's primary reinforcing properties.
• Prior drug exposure significantly influences subsequent drug-seeking behavior.