Thy1-GCaMP6 Transgenic Mice for Neuronal Population Imaging In Vivo

Abstract

Genetically-encoded calcium indicators (GECIs) facilitate imaging activity of genetically defined neuronal populations in vivo. The high intracellular GECI concentrations required for in vivo imaging are usually achieved by viral gene transfer using adeno-associated viruses. Transgenic expression of GECIs promises important advantages, including homogeneous, repeatable, and stable expression without the need for invasive virus injections. Here we present the generation and characterization of transgenic mice expressing the GECIs GCaMP6s or GCaMP6f under the Thy1 promoter. We quantified GCaMP6 expression across brain regions and neurons and compared to other transgenic mice and AAV-mediated expression. We tested three mouse lines for imaging in the visual cortex in vivo and compared their performance to mice injected with AAV expressing GCaMP6. Furthermore, we show that GCaMP6 Thy1 transgenic mice are useful for long-term, high-sensitivity imaging in behaving mice.

Brain heating induced by near-infrared lasers during multiphoton microscopy

“…Because photodamage can be mediated by fluorophore excitation, we conducted these experiments with both wild-type mice and GP4.12 (GCaMP6S) transgenic mice (Dana et al 2014). As with weakly focused light, increased immunoreactivity was evident at powers of 300 mW and above in both mouse strains following 20-min continuous illumination (Fig.…”

“…One experiment (see Fig. 6) involved GP4.12 mice (Dana et al 2014). Both male and female mice, between 8 and 22 wk of age, were included in studies.…”

Large-scale imaging of cortical dynamics during sensory perception and behavior

“…Importantly, the imaging paradigm presented here should be broadly applicable to other GCaMP6 mouse lines that are developed, such as those that do not require a separate driver line (Dana et al 2014) or those where expression is dependent on Cre recombinase (Madisen et al 2015). In addition, because this line is driven by the tetO system, it provides an orthogonal targeting scheme to Cre control that may be useful for other imaging approaches.…”

Visualization of Calcium Dynamics in Kidney Proximal Tubules

“…These indicators reliably detect rapid calcium transients in various neural cell types in vivo. [24][25][26] Using cultured PTE cells, we performed in vitro confocal microscopy studies; using two-photon microscopy, we examined the in vivo calcium modulations in renal PT cells. The in vitro experiments properly identified the cell types examined and allowed a detailed, properly calibrated examination of the effects of ligands and potential inhibitors on the PT epithelial cellular calcium levels.…”