What is GCaMP6s?
GCaMP6s is a genetically encoded fluorescent Ca[2+] indicator that shows high sensitivity and slow decay kinetics. It consists of the calmodulin-binding peptide M13, a circularly permuted green fluorescent protein and calmodulin.
How do Gcamps work?
It is a synthetic fusion of green fluorescent protein (GFP), calmodulin (CaM), and M13, a peptide sequence from myosin light-chain kinase. When bound to Ca2+, GCaMP fluoresces green with a peak excitation wavelength of 480 nm and a peak emission wavelength of 510 nm.
How does calcium imaging work?
Calcium imaging measures changes in intracellular calcium concentrations, providing an indirect indicator of neural activity. Compared to changes in voltage, fluctuations in calcium levels are much slower and may reflect a summation of signals rather than individual spikes (Wei et al. 2019).
How does fiber photometry work?
Fiber photometry uses the genetically encoded calcium indicator, GCaMP, to record the neural activity of genetically defined subpopulations of neurons through an optic fiber in freely moving animals.
Is GCaMP a protein?
GCaMP protein engineering. GCaMP17 and its progeny11,16 consist of circularly permuted green fluorescent protein (cpGFP)25, the calcium-binding protein calmodulin (CaM), and CaM-interacting M13 peptide26 (Fig. 1a). The CaM/M13 complex is in proximity to the chromophore inside the cpGFP β barrel27.
What is in vivo fiber photometry?
Fiber photometry is an in vivo calcium imaging method that detects average fluorescence intensity changes. Thus, this method is used to measure population neural activity in a freely-behaving animal (Cui et al. 2014).
What is iGluSnFr?
iGluSnFr was developed in 2013 by Loren Looger’s lab to give researchers the ability to monitor glutamate release from neurons and other brain cells in vivo. Glutamate plays a variety of roles in synaptic communication and can trigger other forms of neuronal signaling and regulation.
Why is calcium imaging important?
Calcium ions generate versatile intracellular signals that control key functions in all types of neurons. Imaging calcium in neurons is particularly important because calcium signals exert their highly specific functions in well-defined cellular subcompartments.
What are calcium sensors?
The Ca2+ sensors used to transduce changes in cellular Ca2+ into changes in fluorescence must bind Ca2+ to produce a signal. By binding Ca2+, these sensors can act as buffers, often reducing the magnitude of a Ca2+ change several fold and producing a proportional slowing of the rates of change.
Is fiber a photometry imaging?
Fiber photometry is an imaging method that enables scientists to image population-level neural activity in the brain of freely-behaving animals.
What is Chemogenetic stimulation?
Chemogenetics is the process by which macromolecules can be engineered to interact with previously unrecognized small molecules. Chemogenetics as a term was originally coined to describe the observed effects of mutations on chalcone isomerase activity on substrate specificities in the flowers of Dianthus caryophyllus.