Single Action Potentials and Subthreshold Electrical Events Imaged in Neurons with a Fluorescent Protein Voltage Probe

José Wu — Mon, 12 Jan 2015 09:55:47 +0000

A genetically encoded sensor of membrane potential, FlaSh, was first introduced by Siegel and Isacoff (1997) as a fusion between the Shaker potassium channel and wild-type green fluorescent protein from Aequorea victoria (aqGFP).

Subsequent ion channel-based voltage sensors were designed to include a single fluorescent protein or FPs that form Förster Resonance Energy Transfer pairs (FRET).

Later sensors based on the voltage-sensing domain of Ciona intestinalis voltage-sensitive phosphatase (CiVSP) produced robust signals in mammalian cells.

These group have combined many Ciona intestinalis voltage sensor (CiVS) with different FPs to produce FP voltage sensors with improved properties.

However, to date this approach had not yielded probes with the necessary combination of signal size and speed that would make it possible to image individual voltage signals in neurons:
1. Action potentials
2. Subthreshold potentials

This paper report the development of an FP voltage sensor, named ArcLight, which is based on a fusion of the CiVS and the fluorescent protein super ecliptic pHluorin that carries an A227D mutation.

Tags:

CiVP

ArcLight

Voltage sensitive dye

group meeting

Consciousness, a subject for scientific study?

cjj — Fri, 30 May 2014 13:27:55 +0000

There is a recent preprint on the arXiv about defining consciousness with a so called Integrated Information Theory. Will this be relevant to the study of neuronal networks in vitro? It was not straightforward from the manuscript how we can quantify the postulated requirements in our systems. For example, how can we calculate $\Phi^\rm{max}$ for a cultured network with limited number of neurons? Or, what about a simulated network in silico?

The arguments presented in the manuscript seem moving. This can even be a close approximation to the real thing if there is indeed. However, the hit is not strong that will make one feel right on. All the elaboration also creates distance from acceptance. But, can there be anything better?

Laboratory of Computing Biological Networks blogs

Single Action Potentials and Subthreshold Electrical Events Imaged in Neurons with a Fluorescent Protein Voltage Probe

Consciousness, a subject for scientific study?