Browsing by Author "Halinen, Iida"

Alcohol use disorder (AUD) is a chronic relapsing brain disorder causing a high burden of disease and significant social and economic consequences to both individuals and society. Alcohol addiction, the most severe form of AUD, is characterized by compulsive seeking and use of alcohol, loss of control over limiting alcohol consumption despite negative consequences, emergence of negative emotional states, and long-lasting vulnerability to relapse related to alcohol abstinence. Powerful craving for alcohol and the chronic, relapsing nature of the disease are major problems complicating recovery from alcohol addiction and predicting poor clinical outcome. Relapse to alcohol intake can occur even after an extended period of abstinence in humans, relapse rates being highest during the first three months of alcohol withdrawal. Associative learning is a critical factor in alcohol craving when alcohol consumption is accompanied by conditioned stimulus. Cues associated with alcohol are known to induce craving and alcohol-seeking behavior increasing the risk of relapse, and this craving can be triggered by alcohol itself, alcohol-associated stimulus, or stress. Chronic alcohol exposure has been linked to changes in synaptic plasticity, neurogenesis and cell-signaling. Thus, elucidating the neural mechanisms that underlie alcohol craving and relapse would help to understand the pathology of alcohol addiction and facilitate the development of efficient treatments. In this experiment, the effects of subanesthetic-dose 10 mg/kg ketamine, an NMDAR antagonist and a major inducer of synaptic plasticity, on cue-induced alcohol-seeking behavior after withdrawal were investigated in social context in female mice. Mice were trained to voluntarily drink alcohol, and a novel methodology to study alcohol-seeking behavior after withdrawal allowed to perform the experiment with a minimum of human interference in totally automated social home cage environment. The analyses of behavioral data showed that pairing sweetened alcohol with conditioned stimulus resulted in cue-induced alcohol-seeking behavior, and no differences in alcohol conditioning were observed between treatment groups. However, the behavioral activity in extinction tests after withdrawal showed that alcohol-seeking behavior was not altered by ketamine treatments. In biochemical analyses, the effects of subanesthetic-dose ketamine on ΔFosB and BDNF protein levels in the brain areas important for alcohol addiction were studied. ΔFosB expression levels in the mouse nucleus accumbens were analyzed with western blot and BDNF protein levels in the mouse prefrontal cortex were determined using enzyme-linked immunosorbent assay (ELISA). The results from biochemical analyses showed that levels of ΔFosB and BDNF were unaltered by ketamine treatments. Anyhow, the experiment provided important insights into the interactions of ketamine and alcohol craving and relapse, a topic that has been insufficiently studied in novel preclinical models.