We will show how to record flash responses from single mouse cones using a suction electrode.
Making electrodes
Setting up the experiment
Isolating the mouse retina
Recordings
Solutions
Single-cell suction recording from photoreceptor cells was developed 3 decades ago. It enables us to record trans-membrane current change induced by light stimulation without penetrating the cell membrane. Because of high cell-cell adhesion, it is difficult to isolate healthy single rod and cone from mouse retina like amphibian retina and it is hard to find individual cones due to the low percentage (3%) and small size. The inner-segment-in (IS-in) recording method overcomes this difficulty by recording current from the inner segments of several photoreceptors, among which a cone might be included. In wild type mouse, the response should be the combination from rods and cones. A steady background light can be used to suppress rod responses. In this video, we used Tα-/- retina, in which rods can not respond to light stimulation, as they lack the α-subunit of the G-protein transducin 6. Therefore, the photoresponse is only from cones.
Supported by Career Development Award from Research to Prevent Blindness, NIH grant EY 019312, and unrestricted grant from Research to Prevent Blindness and EY 02687 (Department of Ophthalmology & Visual Sciences at Washington University).