Imaging Striatal Dopamine Release Using a Non-Genetically Encoded Near-Infrared Fluorescent Catecholamine Nanosensor

Abraham G. Beyene; Kristen Delevich; Jackson Travis Del Bonis-O’Donnell; David J. Piekarski; Wan Chen Lin; A. Wren Thomas; Sarah J. Yang; Polina Kosillo; Darwin Yang; Linda Wilbrecht; Markita P. Landry

To determine the efficacy of nIRCats for imaging dopamine in brain tissue, we used brain slices from the dorsal striatum of the mouse. Given that the dorsal striatum is densely innervated by dopaminergic projections from the substantia nigra pars compacta (SNc) but lacks innervation from neurons that release norepinephrine (NE) 25 , we leveraged nIRCats capacity to serve as a dopamine sensor in the striatum. The majority of neurons within the striatum are GABAergic medium spiny neurons (MSNs) with a minority fraction of interneuron populations that include GABAergic and cholinergic interneurons. 26 Glutamatergic inputs from the cortex and thalamus are the major drivers of MSN activity and dopaminergic terminals in close proximity to these inputs are thought to play an important role in modulating the activity of MSNs and plasticity at striatal synapses. 27 Due to the composition of local axons, intrastriatal electrical stimulation is predicted to drive the release of a mix of neurotransmitter including GABA, glutamate, acetylcholine, and dopamine, but negligible amounts of other catecholamines like norepinephrine.