Single Photoreceptor Electrophysiology

Introduction

The perception of light is central for allmost all animal life on earth. Measuring the electrical response of single photoreceptor cells has provided a deep scientific understanding of the biophysical mechanisms transducing light into electrical signals further processed by the brain.

Electrophysiology is a widespread biophysical technique measuring feeble electric currents produced by cells. In particular, hotoreceptor electrophysiology studies the electric current response of rod or cone cells to light stimulus. Our goal is to use quantum optical methods to study the basic physics of light transduction at the cellular level.

Single Photoreceptor Electrophysiology

Work in Progress

We have developed an experimental apparatus able to provide precision measurements of the electric current response of single rod cells. The apparatus consists of an inverted microscope, a sensitive electronic amplifier able to detect pA currents, a laser-based pipette puller to make glass pipettes holding the rod cells, and a set of micro-manipulators able to precisely position the pipette in the cell-containing sample. Our immediate goal is to reproduce rod-cell responses that have already been presented in the literature and then explore various quantum optical methodologies for the stimulus light. 

This program fits well into our general research program on quantum vision, which consists of synthesizing quantum optics with the physiology of human vision. While we approach this with human subjects along the directions of pupillometry and biometrics, here we study quantum vision in vitro.