Numerical aperture of GRIN lens

[snaki001]

Hi everyone,

I was wondering whether a GRIN lens of less than 0.5 NA could work with the current design of the miniscope ?
What is the minimum NA that allows "good" imaging of neural activity (e.g. with GCaMP6s vs GCaMP6f) ?

Thanks,


   

[Daniel Aharoni]

Hi snaki001,
The main concern I have with lower NA GRIN lenses is they transmit less light which results in you needing to pump more excitation light into the brain to get the same signal out. In our experience, going below a 0.45NA starts to have very noticeable detrimental effects due to increased photo-bleaching and possible heating.