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Full-Text Articles in Behavior and Behavior Mechanisms

Belief About Nicotine Selectively Modulates Value And Reward Prediction Error Signals In Smokers, Xiaosi Gu, Terry Lohrenz, Ramiro Salas, Philip R. Baldwin, Alireza Soltani Feb 2015

Belief About Nicotine Selectively Modulates Value And Reward Prediction Error Signals In Smokers, Xiaosi Gu, Terry Lohrenz, Ramiro Salas, Philip R. Baldwin, Alireza Soltani

Dartmouth Scholarship

Little is known about how prior beliefs impact biophysically described processes in the presence of neuroactive drugs, which presents a profound challenge to the understanding of the mechanisms and treatments of addiction. We engineered smokers' prior beliefs about the presence of nicotine in a cigarette smoked before a functional magnetic resonance imaging session where subjects carried out a sequential choice task. Using a model-based approach, we show that smokers' beliefs about nicotine specifically modulated learning signals (value and reward prediction error) defined by a computational model of mesolimbic dopamine systems. Belief of "no nicotine in cigarette" (compared with "nicotine in …


Exposure To Kynurenic Acid During Adolescence Increases Sign-Tracking And Impairs Long-Term Potentiation In Adulthood, Nicole E. Deangeli, Travis P. Todd, Stephen E. Chang, Hermes H. Yeh, Pamela W. Yeh, David J. Bucci Jan 2015

Exposure To Kynurenic Acid During Adolescence Increases Sign-Tracking And Impairs Long-Term Potentiation In Adulthood, Nicole E. Deangeli, Travis P. Todd, Stephen E. Chang, Hermes H. Yeh, Pamela W. Yeh, David J. Bucci

Dartmouth Scholarship

Changes in brain reward systems are thought to contribute significantly to the cognitive and behavioral impairments of schizophrenia, as well as the propensity to develop co-occurring substance abuse disorders. Presently, there are few treatments for persons with a dual diagnosis and little is known about the neural substrates that underlie co-occurring schizophrenia and substance abuse. One goal of the present study was to determine if a change in the concentration of kynurenic acid (KYNA), a tryptophan metabolite that is increased in the brains of people with schizophrenia, affects reward-related behavior. KYNA is an endogenous antagonist of NMDA glutamate receptors and …