Alteration in Neural Coding

Changes in input-output relationships of rd10 RGCs
One way to describe RGC responses to light is by plotting the strength of these responses to different light intensities (stimulus-response [S-R] curves).  In rd1 mice, these curves shift leftward and have steeper slopes (i.e., cells are sensitive to lower levels of light but cannot differentiate well between low & high levels).  In rd10 mice, degeneration progresses more slowly, so there is a better opportunity to see how changes in S-R curves evolve, and may suggest underlying physiologic mechanisms.  Analysis of collected data is ongoing.

Disruption of the neural code for vision by retinal degenerations
The retina converts light into electrical signals (graded potentials and action potentials, or “spikes”) that may be viewed as a complex code by which retinal neurons represent visual scenes.  RGCs then carry this encoded information to the brain, where the code is interpreted as percepts.  In collaboration with Dr. Mike Abramoff of Ophthalmology, we are analyzing specific elements of this encoding scheme, to identify which of these encode cell-specific or image-specific information, as well as which are disrupted in retinal degenerations.