1/n Fresh on #bioRxiv: a simple and ultra-low-cost #openhardware approach to upgrade an out-of-the-box two-photon system to reach a 3.5(xy) x 0.6 (z) mm field of view for mesoscale 3D random access scans. /w @FilipKJaniak et al. bit.ly/2BRTrJq
2/n Our ‘diverging beam optics’ (DBO) approach exploits the fact that in 2P microscopy there is no traditional collection plane. This means the images does not get blurry if the incoming laser beam is not parallel as it would in 1P microscopy. 
3/n using DBO, we can flexibly set our field of view and excitation volume to match the structural properties of different biological samples. This is critical, as different species have vastly different size and density neural processes...
4/n We can also tailor the point spread function (PSF) semi-independently of the field of view (FOV). For example, here two versions of a 1.2 mm diameter FOV of a test slide imaged with different size PSF.
5/n We demonstrate the capability of our system using a range of examples from mice, zebrafish and fruit flies. For example, here is what mesoscale imaging in mouse cortex looks like /w @MMaravall @BaleNeuro
6/n Here some traces, including from a vertical scan through layers 1-4
7/n Or mesoscale imaging and random access jumps in mouse brain slice capturing the whole width of the hippocampus plus the overlaying cortex /w @KStaras
8/n Here an example of 3D plane-bending to image a zebrafish brain. The video shows different curvatures applied. This allows key structures such as the optic tectum to be captured along their retinotopic axes.
9/n Similarly, we can also simultaneously record the activity of retinal ganglion cells both in the eye and in the brain
10/n And here an example of optogenetic circuit mapping in a larval fruit fly. Activation of CsChrimson in olfactory sensory neurons elicits specific response patterns across the brain, highlighting antennal lobe, mushroom bodies etc. /w @neuroluci
Great collaboration with @pbartel @BaleNeuro @TaYoshimatsu @KStaras @neuroluci @teulerlab @MMaravall
(and I got Philipps wrong twitter handle. @Philipp_Bartel is the one intended)
Read the full paper at @biorxiv_neursci biorxiv.org/content/10.110…
