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Full-Text Articles in Behavioral Neurobiology
The Role Of The Direct And Indirect Basal Ganglia Pathways In The Learning, Performance, And Goal-Directed Control Of Action Sequences, Eric Garr
Dissertations, Theses, and Capstone Projects
Animals engage in intricately woven action sequences that are constructed from trial-and-error learning, but the mechanisms by which the brain links together individual actions which are later recalled as fluid chains of behavior are not fully understood. The aim of this dissertation is to investigate the learning and goal-directed control of action sequences in rats. Experiment 1 addresses a question that comes out of a reinforcement learning model of action sequencing: how does the extent of training change how the performance of an action sequence is impacted by reward devaluation. The data show that action sequences remain goal-directed overall regardless …
Possible Breakdown Of Dopamine Receptor Synergism In A Mouse Model Of Huntington's Disease, Samantha F. Kennedy
Possible Breakdown Of Dopamine Receptor Synergism In A Mouse Model Of Huntington's Disease, Samantha F. Kennedy
University of New Orleans Theses and Dissertations
The model of basal ganglia function proposed by Albin, Young and Penney (1989) describes two anatomically independent motor pathways, the direct and indirect. However, under normal conditions striatal dopamine (DA) is required for the expression of motor behavior, and DAergic control of the two pathways (via D1 and D2 receptors, respectively) is dependent on co-activation. We tested for a possible breakdown of D1/D2 synergism using transgenic R6/1 mice bearing the human huntingtin allele (Htt). Motor stereotypy, observed prior to the onset of HD-related symptoms, was rated on a 5-point scale following activation of: A) D1 receptors alone, B) D2 receptors …