Dynamic recording of membrane potential from hippocampal neurons by using a FRET-based voltage biosensor

Abstract

Fluorescence-based biosensors for membrane voltage (mV) allow dynamic optical recording of neuronal activity. Interestingly, the development of genetically encoded voltage indicators constitute a good alternative to classical voltage-sensitive dyes, thus allowing overcoming some of the inherent problems (e.g., optical noise, etc.) associated with these organic compounds. Here, we show the use of a genetically encoded voltage-sensitive fluorescent protein (VSFP), namely the VSFP2.32, which contains a mCerulean and Citrine tandem engaging in a constitutive fluorescent resonance energy transfer (FRET) process. By expressing VSFP2.32 in hippocampal cultured neurons, we were able to monitor mV alterations in single neurons by recording VSFP2.32 conformation-mediated FRET changes in a real-time mode.