Involvement of kappa type opioids on ethanol drinking

Area of Science:

• Neuroscience
• Pharmacology
• Behavioral Science

Background:

• Dynorphinergic systems are implicated in various behaviors.
• Opioid receptors, particularly kappa-type, play a role in substance use disorders.

Purpose of the Study:

• To investigate the effect of the kappa agonist dynorphin1-17 and antagonist MR-2266-BS on ethanol preference in rats.
• To explore the role of kappa-opioid mechanisms in ethanol consumption and preference development.

Main Methods:

• Rats were subjected to a paradigm to develop alcohol preference.
• Dynorphin1-17 and/or MR-2266-BS were administered at different time points relative to conditioning and testing.
• Ethanol preference was measured over consecutive testing days.

Main Results:

• Dynorphin administration before conditioning did not alter ethanol preference.
• Dynorphin administration before the choice session significantly reduced ethanol preference.
• The reduction in ethanol preference by dynorphin was reversed by the kappa antagonist MR-2266-BS.

Conclusions:

• Dynorphinergic systems are involved in modulating drinking behavior.
• Kappa-type opioid mechanisms are suggested to be involved in the development and maintenance of ethanol preference in rats.