Cannabinoids and reward: interactions with the opioid system

Area of Science:

• Neuroscience
• Pharmacology
• Addiction Research

Background:

• Cannabis sativa derivatives interact with brain reward systems, mimicking other drugs of abuse.
• Endogenous opioids significantly modulate the addictive potential of cannabinoids.
• Recent literature focuses on cannabinoid-opioid interactions in reward and addiction.

Purpose of the Study:

• To review recent findings on cannabinoid-opioid interactions in reward-related events.
• To summarize evidence of functional cross-talk between cannabinoid and opioid systems.
• To investigate the role of the endogenous cannabinoid system in opioid relapse.

Main Methods:

• Behavioral animal models of addiction to assess cannabinoid reinforcing effects.
• Studies utilizing transgenic mice lacking cannabinoid CB1 or opioid receptors.
• Extinction/reinstatement animal models to examine relapse to opioids after abstinence.

Main Results:

• Cannabinoid and opioid systems exhibit functional cross-talk, mutually modulating addictive behaviors.
• Transgenic mouse data support the interaction between cannabinoid CB1 and opioid receptors.
• The endogenous cannabinoid system plays a role in opioid relapse following abstinence.

Conclusions:

• A bidirectional interaction exists between endogenous cannabinoid and opioid systems in reward pathways.
• This interaction extends to central mechanisms underlying drug relapse phenomena.
• Future research should elucidate the neuroanatomical substrates of cannabinoid actions for therapeutic potential.