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

Mapping Intimacies ◽

10.1101/2021.07.30.454450 ◽

2021 ◽

Author(s):

Daisuke Ino ◽

Hiroshi Hibino ◽

Masaaki Nishiyama

Keyword(s):

Real Time ◽

Dynamic Range ◽

Fluorescent Sensor ◽

Viral Gene ◽

Affinity Ligand ◽

Fluorescence Measurements ◽

Animal Behaviors ◽

Green Fluorescent ◽

The Brain

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.

Download Full-text

Decision letter: Real-time in vivo imaging of extracellular ATP in the brain with a hybrid-type fluorescent sensor

10.7554/elife.57544.sa1 ◽

2020 ◽

Author(s):

Fabio Mammano

Keyword(s):

Real Time ◽

In Vivo Imaging ◽

Fluorescent Sensor ◽

Extracellular Atp ◽

Hybrid Type ◽

The Brain

Download Full-text

Author response: Real-time in vivo imaging of extracellular ATP in the brain with a hybrid-type fluorescent sensor

10.7554/elife.57544.sa2 ◽

2020 ◽

Author(s):

Nami Kitajima ◽

Kenji Takikawa ◽

Hiroshi Sekiya ◽

Kaname Satoh ◽

Daisuke Asanuma ◽

...

Keyword(s):

Real Time ◽

In Vivo Imaging ◽

Fluorescent Sensor ◽

Extracellular Atp ◽

Author Response ◽

Hybrid Type ◽

The Brain

Download Full-text

A New Fluorescent Salen-uranyl Sensor for the Sub-ppm Detection of Chemical Warfare Agents

Current Organic Chemistry ◽

10.2174/1385272824999200930150313 ◽

2020 ◽

Vol 24 (20) ◽

pp. 2378-2382

Author(s):

Andrea Pappalardo ◽

Chiara M.A. Gangemi ◽

Rosa Maria Toscano ◽

Giuseppe Trusso Sfrazzetto

Keyword(s):

Real Time ◽

Fluorescent Sensor ◽

Chemical Warfare Agents ◽

Optical Response ◽

Chemical Warfare ◽

Lethal Effects ◽

Strong Affinity ◽

Chemical Attack ◽

Fluorescence Measurements ◽

Warfare Agents

Real-time sensing of Chemical Warfare Agents (CWAs) is today a crucial topic to prevent the lethal effects of a terroristic chemical attack. For this reason, the development of efficient, selective, sensitive and reversible sensoristic devices, able to detect by optical response ppm levels of these compounds, is strongly required. Here, the synthesis of a new fluorescent sensor based on a salen-uranyl scaffold, functionalized with two bodipy moieties, and its application for the detection of sub-ppm levels of CWAs is reported. Detection properties were evaluated by fluorescence measurements and selectivity tests demonstrated the strong affinity for CWAs.

Download Full-text

GPCR-Based Dopamine Sensors—A Detailed Guide to Inform Sensor Choice for In Vivo Imaging

International Journal of Molecular Sciences ◽

10.3390/ijms21218048 ◽

2020 ◽

Vol 21 (21) ◽

pp. 8048

Author(s):

Marie A. Labouesse ◽

Reto B. Cola ◽

Tommaso Patriarchi

Keyword(s):

In Vivo Imaging ◽

Dynamic Range ◽

New Techniques ◽

Experimental Parameters ◽

Sensor Properties ◽

Molecular Specificity ◽

Freely Behaving ◽

The Brain ◽

Da Release

Understanding how dopamine (DA) encodes behavior depends on technologies that can reliably monitor DA release in freely-behaving animals. Recently, red and green genetically encoded sensors for DA (dLight, GRAB-DA) were developed and now provide the ability to track release dynamics at a subsecond resolution, with submicromolar affinity and high molecular specificity. Combined with rapid developments in in vivo imaging, these sensors have the potential to transform the field of DA sensing and DA-based drug discovery. When implementing these tools in the laboratory, it is important to consider there is not a ‘one-size-fits-all’ sensor. Sensor properties, most importantly their affinity and dynamic range, must be carefully chosen to match local DA levels. Molecular specificity, sensor kinetics, spectral properties, brightness, sensor scaffold and pharmacology can further influence sensor choice depending on the experimental question. In this review, we use DA as an example; we briefly summarize old and new techniques to monitor DA release, including DA biosensors. We then outline a map of DA heterogeneity across the brain and provide a guide for optimal sensor choice and implementation based on local DA levels and other experimental parameters. Altogether this review should act as a tool to guide DA sensor choice for end-users.

Download Full-text

Live View of Gonadotropin-Releasing Hormone Containing Neuron Migration

Endocrinology ◽

10.1210/en.2004-0838 ◽

2005 ◽

Vol 146 (1) ◽

pp. 463-468 ◽

Cited By ~ 33

Author(s):

Elizabeth P. Bless ◽

Heather J. Walker ◽

Kwok W. Yu ◽

J. Gabriel Knoll ◽

Suzanne M. Moenter ◽

...

Keyword(s):

Real Time ◽

Direct Evidence ◽

Gonadotropin Releasing Hormone ◽

Releasing Hormone ◽

Reproductive Axis ◽

Gnrh Neurons ◽

Migratory Route ◽

The Brain

Neurons that synthesize GnRH control the reproductive axis and migrate over long distances and through different environments during development. Prior studies provided strong clues for the types of molecules encountered and movements expected along the migratory route. However, our studies provide the first real-time views of the behavior of GnRH neurons in the context of an in vitro preparation that maintains conditions comparable to those in vivo. The live views provide direct evidence of the changing behavior of GnRH neurons in their different environments, showing that GnRH neurons move with greater frequency and with more changes in direction after they enter the brain. Perturbations of guiding fibers distal to moving GnRH neurons in the nasal compartment influenced movement without detectable changes in the fibers in the immediate vicinity of moving GnRH neurons. This suggests that the use of fibers by GnRH neurons for guidance may entail selective signaling in addition to mechanical guidance. These studies establish a model to evaluate the influences of specific molecules that are important for their migration.

Download Full-text