Joanna Peris, Ph.D.

The Peris lab is currently studying the neurochemical mechanisms of ethanol addiction. As part of this research, we measure how dopaminergic and amino acid neurotransmission in brain reward circuitry (e.g., nucleus accumbens, ventral tegmental area) is altered in rodents exhibiting high degrees of ethanol self-administration. We have developed the “jello shot” method of ethanol self-administration with Dr. Neil Rowland of the Department of Psychology. This model results in pharmacologically relevant levels of ethanol intake in non-genetically-selected rodents, but also controls for non-ethanol reward, caloric consumption and comparable levels of operant responding by the use of non-ethanol gelatin as a control reinforcer. Utilizing a combination of behavioral and microdialysis techniques, we have demonstrated that previous binge ethanol exposures selectively increase ethanol intake, ethanol reward and glutamate levels in nucleus accumbens while not affecting plain gel intake or neurotransmission during plain gel reward. Another novel finding indicates the importance of elevations in glycine in the nucleus accumbens during anticipation of reward.

Our most recent work, in collaboration with Dr. Eric G. Krause, has focused on the role of oxytocin in the regulation of reward circuitry and its impact on ethanol intake. We have found that oxytocin receptors are expressed by both dopamine and glutamate neurons in the ventral tegmental area which might mediate oxytocin inhibition of ethanol intake. We are currently developing optogenetic techniques to address how selective activation of neurons in reward centers that express oxytocin receptors is altered by excessive ethanol intake.