Questions on calcium imaging in Marmoset using Miniscope LFOV

Questions on calcium imaging in Marmoset using Miniscope LFOV

Hi all,

Our lab is interested in exploring whether Miniscope LFOV model could be adapted for optical imaging in marmoset V4. I had a few questions about possible design modifications.

First, given that V4 is relatively superficial compared with many other brain regions, Would it be feasible to use a cranial window with cover glass instead of a GRIN lens?

Second, since we work with marmosets and want to make the most out of each animal, we are interested in a design that would allow us to reposition the miniscope across a larger craniotomy. To my understanding, the Miniscope LFOV has a maximum field of view of approximately 3.6 × 2.7 mm. If we were to make, for example, a 5 × 5 mm craniotomy, we would ideally like a design that allows us to shift the miniscope laterally within that window. Does anyone have experience in working with these kind of problems? Justin Zheng (talk) 21:29, 1 June 2026 (PDT)

Hi Justin! Thanks for being the first person to post a topic to our new forum!

To your first question, the Miniscope V4 has around a 700 to 1000 um front working distance (the distance between the bottom of the scope and the plane that is in focus). Connected to this, 1 photon imaging with Miniscopes can generally maintain single-cell resolution through up to 250 to 300um of tissue. What this means for you is the tissue thickness + cranial window need to be less than 700 to 100 um so the scope can actually focus down to your cells, and that the amount of tissue between the bottom of your cranial window and the cells you want to image should be no more than 300 um. In practice, the latter is usually the issue and becomes the major challenge imaging superficial layers in larger animals.

To your second question, I don't know of anyone that has designed a translational baseplate mounting mechanism for any miniscopes for freely behaving animals. What I have seen is people drilling off the dental cement that holds the baseplate and then repositioning the baseplate... but this isn't done day after day. I would be concerned that any sort of translational stage might not be rigid enough to keep the miniscope stable during behavior. Daniel Aharoni (talk) 10:40, 2 June 2026 (PDT)

Hi Daniel:

Thank you so much for the reply.

I do apologize for the confusion. We are interested using Miniscope LFOV model to image visual cortex (Specifically V4) in the marmoset. To my understanding the working distance of the Miniscope LFOV model is 3.5mm which should be sufficient enough to just have a coverslip. I apologize again for the confusion. Justin Zheng (talk) 11:31, 3 June 2026 (PDT)

Whoops. Right, the MiniLFOV has a working distance of over 3mm but it still has the same fundamental widefield 1-photon depth limitation of around 300 um of tissue before tissue scattering of fluorescence degrades the spatial resolution to the point where you can't resolve single cells.

So the MiniLFOV will give you a few more millimeters (compared to the V4) above the skull but still can only image a few 100 um into tissue. Daniel Aharoni (talk) 12:40, 3 June 2026 (PDT)

Hi Daniel:

Thank you so much for the insights. We will try it out and see. Regarding the DAQ Box, since it is compatible with all previous versions, what would you recommend? Justin Zheng (talk) 18:58, 9 June 2026 (PDT)

I think any UCLA Miniscope DAQ should work. I am not sure but possible the Open Ephys Onyx DAQ also might support the MiniLFOV... or at least it could be udpated to. Daniel Aharoni (talk) 15:43, 10 June 2026 (PDT)