Work

Optogenetic versus electrical stimulation of dopamine terminals in the nucleus accumbens reveals local modulation of presynaptic release

Year: 2015

Type: article

Abstract: The nucleus accumbens is highly heterogeneous, integrating regionally distinct afferent projections and accumbal interneurons, resulting in diverse local microenvironments. Dopamine (DA) neuron terminals similarly express a heterogeneous collection of terminal receptors that modulate DA signaling. Cyclic voltammetry is often used to probe DA terminal dynamics in brain slice preparations; however, this method traditionally requires electrical stimulation to induce DA release. Electrical stimulation excites all of the neuronal processes in the stimulation field, potentially introducing simultaneous, multi‐synaptic modulation of DA terminal release. We used optogenetics to selectively stimulate DA terminals and used voltammetry to compare DA responses from electrical and optical stimulation of the same area of tissue around a recording electrode. We found that with multiple pulse stimulation trains, optically stimulated DA release increasingly exceeded that of electrical stimulation. Furthermore, electrical stimulation produced inhibition of DA release across longer duration stimulations. The GABAB antagonist, CGP 55845, increased electrically stimulated DA release significantly more than light stimulated release. The nicotinic acetylcholine receptor antagonist, dihydro‐β‐erythroidine hydrobromide, inhibited single pulse electrically stimulated DA release while having no effect on optically stimulated DA release. Our results demonstrate that electrical stimulation introduces local multi‐synaptic modulation of DA release that is absent with optogenetically targeted stimulation. image The nucleus accumbens is highly heterogeneous, integrating regionally distinct afferent projections and accumbal interneurons, resulting in diverse microenvironments. Local electrical stimulation excites all of the neuronal processes in the stimulation field, potentially modulating the dopamine signal ‐ measured using cyclic voltammetry. Optogenetically targeting light stimulation to dopamine terminals (blue) reduces the cholinergic and GABAergic modulatory effects on stimulated dopamine release.

Source: Journal of Neurochemistry

DOI: 10.1111/jnc.13177

Authors: James R. Melchior, Mark J. Ferris, Garret D. Stuber, David R. Riddle, Sara R. Jones

Institutions: Wake Forest University Health Sciences, Wake Forest University, University of North Carolina at Chapel Hill, Western Michigan University

Language: English

Topic: Neurotransmitter Receptor Influence on Behavior

Subfield: Cellular and Molecular Neuroscience

Field: Neuroscience

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: green

Funders: National Institutes of Health, Wake Forest School of Medicine, National Institute on Alcohol Abuse and Alcoholism, National Institute on Drug Abuse