Impulsive Behavior is Influenced by Interactions Between Cholinergic and Dopaminergic Neurotransmitter Systems

Our lab is interested in examining relationships between different neurotransmitters in influencing behavior. Two important neurotransmitters are acetylcholine (ACh), which has a role in optimal attentional performance, and dopamine, which is involved in impulsive behavior. As an initial part of a project in our lab, we wanted to examine the previously reported relationship between ACh and dopamine in impulsive behavior. Dopamine neurons in the prefrontal cortex, which is an important brain region for both attention and impulsive behavior, have nicotinic subtypes of ACh receptors (nAChRs) on the presynaptic terminals. The release of ACh in the prefrontal cortex results in stimulation of dopamine neurons to release dopamine via binding of nAChRs by ACh. Dopamine then mediates impulsive behavior via binding of dopamine-1 receptors (D1Rs). Adult Long-Evans rats of both sexes were trained to peak performance on the 5-Choice Serial Reaction Time Task (5-CSRTT), which assesses both attention and impulsive behavior. We then tested the effect of nicotine, a nAChR agonist, and SCH 23390, D1R antagonist, alone and together to better examine the relationship between ACh and dopamine on impulsive behavior, as well as attention.Ope