more synapse

The authors use both mice and rats in their experiment. Mice are used because their genome is largely similar to the human genome. Rats were used because their genome is 92% similar to mice. Rats were also used because they are larger than mice, which makes them a good model organism for examining retinal circuitry. The authors first cloned melanopsin cDNA in rat cells to show that the protein sequence is nearly identical to that of mice. Then they generated specific antibodies targeting melanopsin to show the subset of cells that contained the protein. Tau-lacZ targeting shows the projections of melanopsin positive cells to the SCN and other regions of the brain. Lastly, they used a combination of immunofluorescence and Lucifer Yellow to show that intrinsically photosensitive RGC’s were melanopsin positive.