Electrical Stimulation Evokes Rotational Behavior In Tandem with Exocytotic-like Increases in Dopamine Measured by In Vivo Intracerebral Microdialysis

Background: Electrical Stimulation is a traditional tool in neuroscience and is commonly used in vivo to evoke behavior and in vitro to study neural mechanisms. In vivo intracerebral microdialysis, also a traditional technique, is used to assay neurotransmitter release. However, the combination of these techniques is highly limited to studies using anesthetized animals; therefore, evoking and measuring exocytotic neurotransmitter release in awake models is lacking. Combining these techniques in an awake animal preparation is presented here with evidence to support the mechanistic action of electrical stimulation in vivo.

New methods: This report presents converging evidence to validate the combination of intracerebral electrical stimulation with microdialysis as a novel procedure to study exocytotic-like dopamine release in behaving animals.

Results: It is shown that electrical stimulation of the medial forebrain bundle can be used to evoke frequency- and intensity-dependent exocytotic-like dopamine overflow and rotational behavior that are sensitive to Na⁺ channel blockade and Ca⁺⁺ availability.

Comparison with existing methods: Studies using modern techniques to evoke neurotransmitter release, combined with in vivo intracerebral microdialysis, and measured behavioral output are scarce. In contrast, commonly used pharmacological methods often are less precise and inefficient to evoke exocytotic dopamine release and behavior. Here we demonstrate, the combination of in vivo intracerebral microdialysis with electrical stimulation as a simple approach to simultaneously assess physiologically relevant neurotransmitter 'release' and behavior.

Conclusions: Research that aims to understand how dopamine neurotransmission is altered in behavioral disorders can utilize this innovative combination of electrical stimulation with in vivo intracerebral microdialysis.