2 Introduction

The effects of retinitis pigmentosa (RP) can simultaneously degrade an animal’s behaviors, organs, tissues, and cells. Originating from the disease’s loss of function mutations in the retina, electron microscopy images have shown that rod photoreceptor cells die and behavioral studies have shown that animals have difficulty navigating their environment. These observed changes are impactful in guiding treatment development for RP, yet the physiological changes that occur in between rod cell death and night blindness need clarification (Wright).

Instead of studying the firing of spikes by assuming a model, an additional framework to characterize the encoding of retinal responses is also by examining the consistency of the spike trains across repeated trials of the same stimuli. This approach allows taking two directions: estimating the mutual information transmitted about the stimuli and a measure of the spike train distances across the trials. The two approaches differ because the mutual information quantifies the amount of information a neuron or group of neurons sends to the brain about a stimulus. While spike distance metrics try to provide insights about the precision of the neuronal code. These two metrics have utility in studying a disease because they evaluate the retina’s reliability in encoding its stimuli as a disease progresses and after genetic treatment.

The major role of the retina is to encode the specifics of our visual environment through both the quantity and the precise timing of action potentials and RP disrupts this process. Visual details about time and space are sent through axons in the optic nerve that get transformed into perceptions that will inform an animal’s actions. Beginning from the damage to the photoreceptors, RP in the retina operates by a process of scaling down this sensory information transmission mechanism. Therefore, understanding the changes to the information content and the changes to the spike firing precision have utility in this neurodegenerative context.