Ubisol-Q10 Treatment Prevents Substantial Memory Loss and Reduces β-Amyloid Plaques in a Transgenic Mouse Model of Alzheimer’s Disease

There is currently no cure for Alzheimer’s disease (AD), a progressive, neurodegenerative disease that causes severe memory deficits and personal hardship. Animal models are useful for studying the progression of AD as neurodegeneration begins in the region of the brain called the hippocampus, which leads to changes in specific cognitive functions, such as spatial working memory. The Y-maze and novel object recognition (NOR) tests are frequently used in research to study working memory however, the novel location / novel object recognition (NL/NOR) test was developed more recently to study hippocampal-dependent spatial memory. When treated with water soluble coenzyme-Q10, calledubisol-Q10, cell cultures expressing human mutant presenilin-1 (PSEN1) show reduced levels of β-amyloid and protection against harmful reactive agents. This research suggested that ubisol-Q­10 may be an effective treatment for AD. The current study uses a double transgenic mouse model of AD expressing human mutant amyloid precursor protein (APP) and PSEN1 (1 – 1.5 year old male B6.Cg-Tg with APP/PSEN1) to investigate the effects of orally-administered ubisol-Q10 (fed 50 µg / mL in water supply starting at 1 month old) on tests of long-term memory and spatial working memory using modified Y-maze, NOR, and NL/NOR tests, compared to wild type mice (1 – 1.5 year old male C57BL/6J). Results using Repeated Measures ANOVA show that both wild type and ubisol-Q10 treated APP/PSEN1 mice perform better on tests of long-term memory and spatial memory compared to untreated APP/PSEN1 mice. The histopathological studies conducted after the behavioral tests confirm these results. Ubisol-Q10 treated APP/PSEN1 mice show remarkably low numbers of β-amyloid plaques in the hippocampus and cortex compared to untreated APP/PSEN1 mice. This study provides evidence to support the use of ubisol-Q­10 treatment in AD and further research should continue to investigate the cognitive and neurobiological effects of ubisol-Q10

Spatiotemporal visual statistics of aquatic environments in the natural habitats of zebrafish

Abstract Animal sensory systems are tightly adapted to the demands of their environment. In the visual domain, research has shown that many species have circuits and systems that exploit statistical regularities in natural visual signals. The zebrafish is a popular model animal in visual neuroscience, but relatively little quantitative data is available about the visual properties of the aquatic habitats where zebrafish reside, as compared to terrestrial environments. Improving our understanding of the visual demands of the aquatic habitats of zebrafish can enhance the insights about sensory neuroscience yielded by this model system. We analyzed a video dataset of zebrafish habitats captured by a stationary camera and compared this dataset to videos of terrestrial scenes in the same geographic area. Our analysis of the spatiotemporal structure in these videos suggests that zebrafish habitats are characterized by low visual contrast and strong motion when compared to terrestrial environments. Similar to terrestrial environments, zebrafish habitats tended to be dominated by dark contrasts, particularly in the lower visual field. We discuss how these properties of the visual environment can inform the study of zebrafish visual behavior and neural processing and, by extension, can inform our understanding of the vertebrate brain

Optic flow in the natural habitats of zebrafish supports spatial biases in visual self-motion estimation

Animals benefit from knowing if and how they are moving. Across the animal kingdom, sensory information in the form of optic flow over the visual field is used to estimate self-motion. However, different species exhibit strong spatial biases in how they use optic flow. Here, we show computationally that noisy natural environments favor visual systems that extract spatially biased samples of optic flow when estimating self-motion. The performance associated with these biases, however, depends on interactions between the environment and the animal's brain and behavior. Using the larval zebrafish as a model, we recorded natural optic flow associated with swimming trajectories in the animal's habitat with an omnidirectional camera mounted on a mechanical arm. An analysis of these flow fields suggests that lateral regions of the lower visual field are most informative about swimming speed. This pattern is consistent with the recent findings that zebrafish optomotor responses are preferentially driven by optic flow in the lateral lower visual field, which we extend with behavioral results from a high-resolution spherical arena. Spatial biases in optic-flow sampling are likely pervasive because they are an effective strategy for determining self-motion in noisy natural environments