2,3,7,8-TCDD Effects on Visual Structure and Function in Swim-Up Rainbow Trout
| Autor: | Donald E. Tillitt, Paulo S. M. Carvalho |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Retinal Ganglion Cells
Polychlorinated Dibenzodioxins Visual acuity genetic structures Trout Vision Disorders Biology Retinal ganglion chemistry.chemical_compound Cytochrome P-450 CYP1A1 medicine Animals Environmental Chemistry Scotopic vision Neurons Retina Dose-Response Relationship Drug Choroid Brain Retinal General Chemistry Anatomy Immunohistochemistry eye diseases medicine.anatomical_structure chemistry Environmental Pollutants Rainbow trout sense organs medicine.symptom Neuroscience Photopic vision |
| Zdroj: | Environmental Science & Technology. 38:6300-6306 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es034857i |
| Popis: | An understanding of mechanisms of contaminant effects across levels of biological organization is essential in ecotoxicology if we are to generate predictive models for population-level effects. We applied a suite of biochemical, histological, and behavioral end points related to visual structure and function and foraging behavior to evaluate effects of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) on swim-up rainbow trout. We detected a dose-dependent decrease in densities of retinal ganglion cells (RGC), key retinal neurons that link the eye with the brain. These changes resulted in corresponding deficits in visual/motor function including reductions in visual acuity and in scotopic and photopic thresholds due to TCDD. The loss of RGCs suggests an increase in convergence of synapses from photoreceptors to RGCs as a cellular mechanism for the visual deficits. Dose-dependent increases in immunohistochemical detection of CYP1A protein in the vasculature of the brain and eye choroid was proportional with decreased ganglion cell densities in the retina. TCDD-induced AHR-regulated effects on these tissues might be involved in the detected decrease in ganglion cell densities. Prey capture rate decreased after TCDD exposure only atthe highesttreatment groups evaluated. Collectively, these results show that TCDD causes biochemical and structural changes in the eye and brain of rainbow trout that are associated with behavioral deficits leading to decreased individual fitness. |
| Databáze: | OpenAIRE |
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