Thy1transgenic mice expressing the red fluorescent calcium indicator jRGECO1a for neuronal population imagingin vivo

Abstract

Calcium imaging is commonly used to measure the neural activity of large groups of neurons in mice. Genetically encoded calcium indicators (GECIs) can be delivered for this purpose using non-invasive genetic methods. Compared to viral gene transfer, transgenic targeting of GECIs provides stable long-term expression and obviates the need for invasive viral injections. Transgenic mice expressing the green GECI GCaMP6 are already widely used. Here we present the generation and characterizarion of transgenic mice expressing the sensitive red GECI jRGECO1a, driven by the Thy1 promoter. Four transgenic lines with different expression patterns showed sufficiently high expression for cellular in vivo imaging. We used two-photon microscopy to characterize visual responses of individual neurons in the visual cortex in vivo. The signal-to-noise ratio in transgenic mice was comparable to, or better than, for mice transduced with adeno-associated virus.We also show that Thy1-jRGECO1a transgenic . CC-BY-NC-ND 4.0 International license It is made available under a (which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint . http://dx.doi.org/10.1101/284497 doi: bioRxiv preprint first posted online Mar. 18, 2018; mice are useful for transcranial population imaging and functional mapping using widefield fluorescecnce microscopy. We also demonstrate imaging of visual responses in retinal ganglion cells. Thy1-jRGECO1a transgenic mice are therefore a useful addition to the toolbox for imaging activity in intact neural networks.

Localized semi-nonnegative matrix factorization (LocaNMF) of widefield calcium imaging data

“…Data type (2) Following are the experimental details for widefield imaging experiments involving an adult Thy1-jRGECO1a mice (line GP8.20, purchased from Jackson Labs) 43 . In preparation for widefield imaging, a thinned-skull craniotomy was performed over the cortex, in which the mouse was anesthetized with isoflurane, had its skull thinned, and was implanted with an acrylic headpiece for restraint.…”

<i>Thy1</i> promoter activity in the <i>Rosa26</i> locus in mice: lessons from Dre-<i>rox</i> conditional expression system

“…3 and 4), suggesting highly reproducible Thy1 promoter activity in lines generated by PITT. This is an advantage for targeted transgenesis and is an improvement over laborious and time-consuming traditional methods for obtaining Tg lines [6]. Our results suggest promise for targeted transgenesis-based methods for acquisition of Tg mice, without subsequent selection among generated mice for suitable Tg lines.…”

“…These Tg mice are mainly used for analyses of gene functions in the brain, where the Thy1 promoter is predominantly active. In general, however, transgene expression patterns vary and can be biased in Tg offspring produced by random integration-based transgenesis techniques [6], [13].…”

The sperm hook in house mice: a functional adaptation for migration and self-organised behaviour

“…We imaged three cleared samples from three different females. In one sample (Figure 3A), only the intramural UTJ part was excised from one unmated transgenic C57BL/6J female mouse -a hybrid female that was delivered from Cx3cr1 female and Thy1 male (JAX stock #030526) called Tg(Thy1-jRGECO1a)GP8.31Dkim (Dana et al, 2018). Another sample was from a female that was mated with a vasectomized RBGS-Cx3cr1 male.…”