Effects of self- and experimenter-administered cocaine on subsequent ethanol drinking in rhesus monkeys.

Background: One possible reason for the lack of FDA-approved pharmacotherapies to treat cocaine use disorder (CUD) is that, although cocaine is typically used in combination with alcohol, it is studied in isolation in preclinical studies. A better understanding of the cocaine-alcohol interactions that promote polysubstance use (PSU) will improve animal models of CUD and hasten pharmacotherapy development. We used a rhesus monkey model of cocaine-alcohol PSU to investigate one possible mechanism: that alcohol is used to mitigate negative effects associated with termination of cocaine use.

Influence of social rank on the development of long-term ethanol drinking trajectories in cynomolgus monkeys.

Background: Chronic stress contribute to the development of alcohol use disorder (AUD). However, characterizing the role of chronic social stressors in the development of problematic drinking trajectories in humans is complicated by practical and ethical constraints. Group-housed nonhuman primates develop social dominance hierarchies that represent a continuum of social experiences from enrichment in higher-ranked (dominant) monkeys to chronic social stress in lower-ranked (subordinate) individuals.

Association of dopamine D2-like and D receptor function with initial sensitivity to cocaine reinforcement in male rhesus monkeys.

Identifying neurobiological characteristics that predict the development of cocaine use disorder would be of great value in prevention efforts. Because of their importance in mediating the abuse-related effects of cocaine, brain dopamine receptors are logical candidates for investigation. We analyzed data from two recently published studies that characterized availability of dopamine D2-like receptors (D2R) with [C]raclopride PET imaging and dopamine D receptor (DR) sensitivity with quinpirole-induced yawning in cocaine-naïve rhesus monkeys who subsequently acquired cocaine self-administration and completed a cocaine self-administration dose-effect curve.

Effects of chronic cocaine and ethanol self-administration on brain dopamine receptors in a rhesus monkey model of polysubstance abuse.

Most individuals with cocaine use disorder also use alcohol; however, little is known about the behavioural and pharmacological mechanisms that promote co-abuse. For example, although studies in humans and animals have documented that chronic use of either alcohol or cocaine alone decreases D2-like receptor (D2R) availability, effects of co-abuse of these substances on dopamine receptor function have not been characterized. These studies examined the effects of long-term cocaine self-administration in 12 male rhesus monkeys who also consumed either ethanol or an ethanol-free solution each day (n = 6 per group).