Reduced extracellular dopamine and increased responsiveness to novelty: neurochemical and behavioral sequelae of intermittent hypoxia.

Study Objectives: Vesicular monoamine transporter and dopamine D1-receptor protein expression are upregulated within the striatum of adults rats exposed to intermittent hypoxic insults as neonates. These observations prompted us to test the hypothesis that intermittent hypoxic insults, occurring during this period of critical brain development, lead to persistent reductions in extracellular levels of dopamine within the striatum. We also tested the hypothesis that post-hypoxic rats exhibit increased novelty-induced behavioral activation and increased basal levels of locomotor activity, two indexes of impaired dopaminergic functioning.