Assessing Direct Effects of Thyroid Hormone (T3) on Corneal Transparency Using Organotypic Chick Half-Head Culture
Major
Neuroscience
Submission Type
Poster
Area of Study or Work
Biology, Neuroscience
Faculty Advisor
Tyler Schwend
Location
CNS Atrium
Start Date
4-11-2026 11:15 AM
End Date
4-11-2026 12:30 PM
Abstract
Clear vision depends on proper light transmittance through a transparent cornea. Embryonic chick corneas begin as an opaque tissue that becomes progressively transparent throughout the second half of embryonic development (E10-E20) before reaching maximum pre-hatching transparency at E20. Although previous work showed that the development of corneal transparency in the chick can be accelerated or delayed by modulating embryonic thyroid hormone levels, whether the cornea relies on endogenous TH to achieve maximum pre-hatching transparency is unclear. Moreover, details underlying the stimulatory effect of TH on corneal transparency are poorly understood. To test whether TH can act directly on corneal cells in a cell-autonomous manner, we carried out an organotypic culture assay. Embryonic chick half-heads were maintained in vitro in the presence of triiodothyronine (T3). This assay enables us to test whether the presence of T3 can accelerate transparency development in the corneal tissue of the cultured half-head in the absence of systemic circulation. Experimental outcomes have been variable. Across four trials, two experiments have shown that the presence of T3 was capable of accelerating corneal transparency. In the other two trials, we did not see changes in corneal transparency between controls and half-heads exposed to T3; however, these organotypic cultures had high levels of bacterial infection which tends to make all tissues more opaque and less transparent, thus it is hard to interpret our results from these two experiments. Currently, we are repeating the assay, taking steps to assure our techniques are aseptic and approaches are ensuring a bacteria-free culture environment. Results thus far suggest that TH acts on corneal cells directly to influence their transparent state.
Assessing Direct Effects of Thyroid Hormone (T3) on Corneal Transparency Using Organotypic Chick Half-Head Culture
CNS Atrium
Clear vision depends on proper light transmittance through a transparent cornea. Embryonic chick corneas begin as an opaque tissue that becomes progressively transparent throughout the second half of embryonic development (E10-E20) before reaching maximum pre-hatching transparency at E20. Although previous work showed that the development of corneal transparency in the chick can be accelerated or delayed by modulating embryonic thyroid hormone levels, whether the cornea relies on endogenous TH to achieve maximum pre-hatching transparency is unclear. Moreover, details underlying the stimulatory effect of TH on corneal transparency are poorly understood. To test whether TH can act directly on corneal cells in a cell-autonomous manner, we carried out an organotypic culture assay. Embryonic chick half-heads were maintained in vitro in the presence of triiodothyronine (T3). This assay enables us to test whether the presence of T3 can accelerate transparency development in the corneal tissue of the cultured half-head in the absence of systemic circulation. Experimental outcomes have been variable. Across four trials, two experiments have shown that the presence of T3 was capable of accelerating corneal transparency. In the other two trials, we did not see changes in corneal transparency between controls and half-heads exposed to T3; however, these organotypic cultures had high levels of bacterial infection which tends to make all tissues more opaque and less transparent, thus it is hard to interpret our results from these two experiments. Currently, we are repeating the assay, taking steps to assure our techniques are aseptic and approaches are ensuring a bacteria-free culture environment. Results thus far suggest that TH acts on corneal cells directly to influence their transparent state.