رسالة جامعية
The development of outer retinal photoresponsivity and the effects of sensory deprivation
| العنوان: | The development of outer retinal photoresponsivity and the effects of sensory deprivation |
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| المؤلفون: | Bonezzi, Paul J. |
| بيانات النشر: | University of Akron / OhioLINK, 2020. |
| سنة النشر: | 2020 |
| المجموعة: | Ohiolink ETDs |
| Original Material: | http://rave.ohiolink.edu/etdc/view?acc_num=akron1602525875711526Test |
| مصطلحات موضوعية: | Neurobiology, Neurosciences, Physiology, Biology, Biophysics, Cellular Biology, Evolution and Development, Molecular Biology, Optics, retina, photoreceptors, development, rods, cones, retinal processing, mouse, electroretinogram, bipolar cells, sensory deprivation, visual system, phototransduction, electrophysiology |
| الوصف: | Visual processing begins with phototransduction when rod and cone photoreceptors in the outer retina transform incident photons into electrochemical potentials. The unique spectral sensitives of the expressed light-sensitive opsin (s) as well as several other factors shape an individual photoreceptors response properties. Subsequently, photoreceptor outputs distribute amongst distinct postsynaptic partners establishing parallel intraretinal channels for information flow. Furthermore, light-evoked responses in the mouse retina are known to increase significantly after eye-opening between postnatal days 12-14 (P12-14). This correlates with activities of the inner retina, confirming that outer retinal function increases after eye-opening and stabilizes around P30 (maturity). Previous in-vivo electroretinogram (ERG) studies have demonstrated light-evoked photoreceptor activity at P10. Such responses coincide with initial synaptogenesis between photoreceptors and second-order bipolar cells. However, this is a full 2-3 days after synaptogenesis of bipolar cells and third-order ganglion cells that relay retinal outputs to higher-order visual system regions. Moreover, various developmental factors determine the onset of photoreceptor responsivity, one being the gradual increase in phototransduction-specific genes and proteins. In partial disagreement with previous electrophysiological findings, molecular analyses indicate that much of the machinery for cone phototransduction is present before P10 and just before eye-opening in rods. Therefore, it was hypothesized that photoreceptors are responsive and second-order bipolar cells can respond to photoreceptor output days before eye-opening in mice. It was found that photoreceptor-evoked a-waves were detected in response to both green and UV flashes of light at P8 and bipolar cell-evoked b-waves were responsive within the 24 hours to follow using ex-vivo electroretinograms (ERGs). Furthermore, seminal studies have demonstrated that during critical developmental time points, light-evoked activity contributes, in a myriad of ways, to the refinement of higher-order circuits of the visual system. However, few studies have explored the effects of sensory deprivation on photoreceptors and their respective second-order responses. Therefore, it was of interest to determine the role of early sensory experience on the functionality of such retinal circuits. It was determined that deprivation alters both the photoreceptor response properties as well as the second-order responses of ON-bipolar cell responses, but in unique ways. |
| Original Identifier: | oai:etd.ohiolink.edu:akron1602525875711526 |
| نوع الوثيقة: | text |
| اللغة: | English |
| الإتاحة: | http://rave.ohiolink.edu/etdc/view?acc_num=akron1602525875711526Test |
| حقوق: | unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
| رقم الانضمام: | edsndl.OhioLink.oai.etd.ohiolink.edu.akron1602525875711526 |
| قاعدة البيانات: | Networked Digital Library of Theses & Dissertations |
| الوصف غير متاح. |