Bioethics Blogs

Snapshots of Life: Fisheye View

Goldfish retina

Credit: Bryan William Jones and Robert E. Marc, University of Utah, Salt Lake City

It looks like a celebration with confetti and streamers that the photographers—among the winners of the Federation of American Societies for Experimental Biology’s 2013 BioArt Competition—captured in this image. But these dots and lines are actually cells in the retina of a goldfish. And what such images reveal may be far more than just a pretty picture.

NIH-funded researchers at the University of Utah used a set of tools called Computational Molecular Phenotyping (CMP) to take a snapshot of the amacrine cells in the retina. The retina is delicate, light-sensitive tissue in the back of the eye, and its amacrine cells are involved in processing and conveying signals from the light-gathering photoreceptor cells to the brain’s visual cortex, where the image is decoded. The colors in this photograph reveal the unique metabolic chemistry, and thus the identity, of each subtype of neuron. The red, yellow, and orange cells are amacrine neurons with a high level of the amino acid glycine; the blue ones have a lot of the neurotransmitter gamma-aminobutyric acid (GABA). The green color tells us something different: it provides a physiological snapshot revealing which neurons were active and talking to each other at the time the image was created.

By combining all of the data from CMP —cell identity and activity—with structural images from a transmission electron microscope, the researchers were able to build circuit diagrams of the retina that show cell type, location, and neuronal wiring. This map of the neurons in a healthy retina provides a baseline for understanding, and perhaps ultimately treating, diseases of the retina that alter the circuitry.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.