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dc.contributor.authorRiley, Elizabeth Brookeen_US
dc.date.accessioned2016-01-07T18:43:26Z
dc.date.available2016-01-07T18:43:26Z
dc.date.issued2015
dc.identifier.urihttps://hdl.handle.net/2144/13723
dc.description.abstractPsychostimulants are known to alter visual function acutely and on withdrawal, and can cause attention deficit following prenatal exposure. However, psychostimulants can also improve visual attention in patients with attention deficit. The mechanisms involved in these contrasting effects remain largely unknown. To determine the role of specific brain regions and the dopamine system in the impact of cocaine exposure on visual processing, we employed two-photon microscopy and a transgenic larval zebrafish expressing the calcium indicator GCaMP-HS. We documented neuronal responses to contrasting visual stimuli, red light (LF) and dark (DF) flashes. We found that in the optic tectum neuropil (TOn), both stimuli elicited similar responses, though after repeated stimulus presentation, habituation developed to dark flash only. The dorsal telencephalon (dTe) responded and habituated to LF only. Acute cocaine (0.5 μM) reduced neuronal responses to LF in both brain regions and prevented habituation of dTe neurons to LF, but did not modify responses or habituation to dark flash. Prenatal cocaine exposure (PCE) did not modify baseline responses, but it prevented the acute effects of cocaine on LF responses in both regions and habituation in dTe, with no impact on dark flash responses. PCE also significantly reduced D1 dopamine receptor expression in TOn and cerebellum, but not dTe or the eye. Fish lacking the dopamine transporter (DATKO) retained normal D1 expression throughout the brain, baseline responses to LF in both TOn and dTe, and response reduction following cocaine in TOn. However, they demonstrated abnormal swimming behavior, and neither their swimming behavior nor dTe responses to LF were modified by cocaine. We discovered that in zebrafish, a diurnal vertebrate, responses to light not only require the primary visual processing center TO (superior colliculus in mammals), but also higher level processing by dTe. Responses to light but not darkness are modified by cocaine, unless the fish lack DAT or were exposed to PCE. Together, our results demonstrate specific effects of cocaine on visual processing mediated by the dopamine system, and provide a novel animal model for further investigation of these phenomena and development of new therapeutic approaches.en_US
dc.language.isoen_US
dc.rightsAttribution-NonCommercial 4.0 Internationalen_US
dc.rights.urihttp://creativecommons.org/licenses/by-nd/4.0/
dc.subjectNeurosciencesen_US
dc.subjectDopamineen_US
dc.subjectNeuroscienceen_US
dc.subjectOptic tectumen_US
dc.subjectTelencephalonen_US
dc.subjectVisual processingen_US
dc.subjectZebrafishen_US
dc.titleEffects of cocaine on visual processing in zebrafishen_US
dc.typeThesis/Dissertationen_US
dc.date.updated2015-11-03T04:14:00Z
etd.degree.nameDoctor of Philosophyen_US
etd.degree.leveldoctoralen_US
etd.degree.disciplineNeuroscienceen_US
etd.degree.grantorBoston Universityen_US


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Attribution-NonCommercial 4.0 International
Except where otherwise noted, this item's license is described as Attribution-NonCommercial 4.0 International