Basics about calcium imaging

Hi all,

I’m quite new for calcium imaging and wondering how calcium imaging could record signals at different resolution like single cell level, dendrite, or spine level? Does they use different resolution of microscopes? And sometimes the figures are green, sometimes is gray. Is it because of different calcium indicator?
Thank you!

Best,
Mango

It depends on the microscope (epifluorescence, confocal, 2p) and the objective to record spines or somas.
Cameras record in gray scale. However, some indicators are recorded in the green channel (emisison of the proetin, eg GFP or GCAMP) and other in the red channel (tdtomato). When you merge both channels you can use color tables to transform from gray to a desired scale of colors, that is made with software.