In a recent paper published in the Journal of Neurophysiology, the Knöpfel lab (Riken, Japan) introduced a new design variant of FRET-based voltage sensitive fluorescent proteins, termed VSFP-Butterflies, along with an extensive series of application examples in brain slices and living mice. VSFP-Butterfly 1.2 uses red shifted FP, allowing excitation at 488 to 510 nm with acceptor emission > 600 nm. While the sensitivity of VSFP-Butterfly 1.2 is similar to that of VSFP2.3 (around 22% ΔF/F at half maximal activation, V1/2), its fluorescence to voltage relationship is left shifted, resulting in a more sensitive detection of subthreshold potentials as well as of action potentials (fig. 1). VSFP-Butterfly imaging of voltage signals over the cortex of living mice revealed traveling waves generated by the activity of layer 2/3 pyramidal cells (fig 2). The application examples in this report demonstrate that cell class-specific voltage imaging is practical with VSFP-Butterflies. The authors discuss how VSFP-based voltage imaging will opening new avenues towards a better understanding of the neuronal computations reflected in the dynamics of cortical circuits.
TagsBooks chloride ChRs Cryptochrome Dimerizers Electroporation Epilepsy Expression fiberoptics FRET GECI GEVI Highlighters Holography hVoS Indicators LED Lines LOV Opsins Optics Optrodes Phototropin prosthetics protons Pumps Recordings Reporter Retina Reviews Scattering Therapeutics Thoughts Toxicity Viruses Voltage waveguides