The fiber photometry system records changes in the fluorescence intensity of neurons in a specific brain area to reflect neuronal population activity. R820 has three wave lengths, 410nm, 470nm and 560nm, of which 410 is used to acquire reference signal and eliminate noise.
- Ca2 + and neurotransmitter signal detection
- Study the function of neural circuits
- Explore the mechanisms of neurological diseases
- Develop new fluorescent sensor probe
- Experiment of optical principle
Fiber photometry is a technology to detecting the activity of neurons in the brain nucleus of freely moving animals. It sums up the overall fluorescence of neurons expressing a genetically encoded calcium indicator(GECI) and neurotransmitter probes. It can be used to explore the regulatory mechanisms behind animal behavior.
In fiber photometry, data are collected by analyzing the fluorescence change (ΔF) relative to the initial baseline fluorescence (F) and observing the signal change corresponding to the calcium transient (ΔF/F). These metrics are usually based on fluorophores such as GFP, RFP, tdTomato, mCherry, etc., of which GCaMP is the most common example.
In neurons, calcium ions regulate several important processes, including neurotransmitter release and membrane excitability. GCaMP can provide critical insight into calcium dynamics, as GCaMP fluoresces only when bound to calcium ions. Based on similar principles, fiber photometry systems can also detect changes in the concentration of neurotransmitters.
(Neurotransmitter probes – cpEGFP is embedded in a specific neurotransmitter receptor, and the binding of the receptor to the neurotransmitter triggers a conformational change in the receptor to convert to a fluorescent signal, and this genetically encodable probe is expressed in cells or mouse brain by viral injection, transfection, and other technical means.)