Date of Award

4-2007

Degree Type

Thesis

Degree Name

MS Experimental Psychology

Department

Psychology

Advisor

Michael Vigorito

Committee Member

Sulie L. Chang

Committee Member

Amy J. Silvestri

Keywords

Spatial learning deficit, HIV-1, Transgenic rats

Abstract

HIV -1 infection is associated with a constellation of cognitive and motor deficits collectively termed HIV associated dementia. With the onset of HAART treatment, these cognitive effects have become more mild, but also more prevalent. The lack of a proper animal model to study these cognitive effects of HIV has lead to the development of a new transgenic rat. This rat expresses the HIV -1 genome with functional tat and gp 120 viral proteins. These proteins are linked with direct neural toxicity as well as the induction of cytokines and other indirect means of neuronal damage. As part of the transgenic process, however, the HIV Tg rats express prominent cataracts, which can hinder cognitive testing that relies on visual stimuli. In order to test the spatial ability of these rats, a modified Morris water maze was developed that does not require the use of visual cues. A combination of olfactory, auditory, and tactile cues compensate for the lack of visual cues in this modified maze. First, a pilot study was performed to test the validity of the modified maze. Second, HIV Tg rats as well as F Tg littermate controls and normal F controls were run in the modified Morris water maze to test for spatial deficits. Lastly, a third experiment was performed, again with HIV Tg, F Tg, and Frats to determine the nature of the spatial deficit in these rats as well as test reversal and strategy learning. Results of all three experiments indicate that rats are able to solve a modified Morris water maze, and that HIV -1 T g rats display deficits in place learning, reversal learning, and strategy learning compared to controls. These: results parallel effects seen in the human population and implicate the HIV -1 T g rat as a good model to explore potential treatment of the cognitive effects associated with HIV -1 infection.

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