Retinal Sensitivity of Hormonally Modulated Hyla cinerea Using Electrophysiological Techniques

Publication Date

July 2019

Location

LSU Health Medical Education Building

Document Type

Abstract

Start Date

26-7-2019 9:00 AM

End Date

26-7-2019 12:00 PM

Description

Hormones modulate the nervous system to regulate reproductive behavior and the processing of visual signals. However, little is known of how endocrine mechanisms modulate the retina, the peripheral sensory layer in the eye that is responsible for the transduction of light to electrophysiological events in the central nervous system. The goal of this study was to determine whether reproductive state is correlated with increased retinal sensitivity in vertebrates. The retinal physiological sensitivity of non-reproductive and gravid green tree frog, Hyla cinerea, females were measured using scotopic electroretinograms (ERGs). This nocturnal frog is used as an experimental model due to its ability to respond to wavelengths spanning the human visible light spectrum with similar ocular and cellular anatomy. The electrical response to flashes of light were collected using two different experimental protocols. The first approach examined relative spectral sensitivity by comparing ERG b-wave amplitudes for isointensity light flashes at different wavelengths. The second approach measures b-wave amplitude across a series of light intensities, enabling calculation of retinal threshold at each wavelength. Our preliminary data show increased electrophysiological response size and decreased thresholds in reproductive females. The results are significant, as the elucidation of peripheral sensory function under different endocrine states has potential clinical applications for treating degenerative retinal diseases such as retinitis pigmentosa. These data provide the first step toward such therapeutic approaches.

Comments

Mentor: Hamilton Farris, PhD, Neuroscience Center of Excellence, Department of Cell Biology and Anatomy

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Jul 26th, 9:00 AM Jul 26th, 12:00 PM

Retinal Sensitivity of Hormonally Modulated Hyla cinerea Using Electrophysiological Techniques

LSU Health Medical Education Building

Hormones modulate the nervous system to regulate reproductive behavior and the processing of visual signals. However, little is known of how endocrine mechanisms modulate the retina, the peripheral sensory layer in the eye that is responsible for the transduction of light to electrophysiological events in the central nervous system. The goal of this study was to determine whether reproductive state is correlated with increased retinal sensitivity in vertebrates. The retinal physiological sensitivity of non-reproductive and gravid green tree frog, Hyla cinerea, females were measured using scotopic electroretinograms (ERGs). This nocturnal frog is used as an experimental model due to its ability to respond to wavelengths spanning the human visible light spectrum with similar ocular and cellular anatomy. The electrical response to flashes of light were collected using two different experimental protocols. The first approach examined relative spectral sensitivity by comparing ERG b-wave amplitudes for isointensity light flashes at different wavelengths. The second approach measures b-wave amplitude across a series of light intensities, enabling calculation of retinal threshold at each wavelength. Our preliminary data show increased electrophysiological response size and decreased thresholds in reproductive females. The results are significant, as the elucidation of peripheral sensory function under different endocrine states has potential clinical applications for treating degenerative retinal diseases such as retinitis pigmentosa. These data provide the first step toward such therapeutic approaches.