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bioRxiv · 10.1101/2021.07.30.454450

A fluorescent sensor for the real-time measurement of extracellular oxytocin dynamics in the brain

Ino, D.·Hibino, H.·Nishiyama, M.
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Abstract

Oxytocin (OT), a hypothalamic neuropeptide that acts as a neuromodulator in the brain, orchestrates a variety of animal behaviors. However, the relationship between brain OT dynamics and complex animal behaviors remains largely elusive, partly because of the lack of a suitable technique for its real-time recording in vivo. Here, we describe MTRIAOT, a G protein-coupled receptor-based green fluorescent OT sensor with a large dynamic range, optimal affinity, ligand specificity to OT orthologs, minimal effects on downstream signaling, and long-term fluorescence stability. By combining viral gene delivery and fiber photometry-mediated fluorescence measurements, we demonstrated the utility of MTRIAOT for real-time detection of brain OT dynamics in living mice. Importantly, MTRIAOT-mediated measurements revealed "OT oscillation," a hitherto unknown rhythmic change in OT levels in the brain. MTRIAOT will allow the analysis of OT dynamics in a wide variety of physiological and pathological processes.

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Ino, D., Hibino, H., Nishiyama, M.. 2021-07-31. A fluorescent sensor for the real-time measurement of extracellular oxytocin dynamics in the brain. https://doi.org/10.1101/2021.07.30.454450

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