Electrical stimulation uses sodium channel dependent depolarization to produce exocytotic-like dopamine release and rotational behavior in vivo
The goal of this project was to establish Electrical Stimulation (ES) in combination with In Vivo Intracerebral Microdialysis (IVMCD) as a methodology to evoke exocytotic-like dopamine (DA) release. To provide evidence that ES mimics action potential-mediated DA exocytosis, we hypothesized that ES produces depolarization of the membrane potential that is dependent upon sodium (Na+) -channels to produce DA release concomitantly with rotational behavior. To test this, rats received electrode and cannulae implants along the medial forebrain bundle, which contains the DAergic nigrostriatal pathway, and a microdialysis probe at the striatum to undergo IVMCD testing. To begin, steady baseline DA levels were assessed followed by ES, subsequent post ES samples were collected, followed by an infusion of Na+ channel blocker, lidocaine. Next, a second phase of ES was applied to assess the effects of lidocaine on ES-evoked DA overflow, and two additional post ES samples followed. The data indicate that lidocaine decreased both basal and electrically stimulated DA release, and reduced associated rotational behavior. The current data support the idea that ES activates Na+ channels to induce exocytotic-like DA release and rotational behavior. These data validate ES in combination with IVMCD as an effective methodology to study plasticity of exocytotic mechanisms that alter DA neurotransmission. Specifically, future research that aims to understand how DA neurotransmission is altered in behavioral disorders, such as neurodegenerative or substance use disorders, can utilize this innovative combination of ES and IVMCD.
Hernandez, Alice Elaine, "Electrical stimulation uses sodium channel dependent depolarization to produce exocytotic-like dopamine release and rotational behavior in vivo" (2015). ETD Collection for University of Texas, El Paso. AAI1591959.