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- Clemensson, Erik K.H., et al.
(författare)
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Tracking Rats in Operant Conditioning Chambers Using a Versatile Homemade Video Camera and DeepLabCut
- 2020
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Ingår i: Journal of visualized experiments : JoVE. - : MyJove Corporation. - 1940-087X. ; :160
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Tidskriftsartikel (refereegranskat)abstract
- Operant conditioning chambers are used to perform a wide range of behavioral tests in the field of neuroscience. The recorded data is typically based on the triggering of lever and nose-poke sensors present inside the chambers. While this provides a detailed view of when and how animals perform certain responses, it cannot be used to evaluate behaviors that do not trigger any sensors. As such, assessing how animals position themselves and move inside the chamber is rarely possible. To obtain this information, researchers generally have to record and analyze videos. Manufacturers of operant conditioning chambers can typically supply their customers with high-quality camera setups. However, these can be very costly and do not necessarily fit chambers from other manufacturers or other behavioral test setups. The current protocol describes how to build an inexpensive and versatile video camera using hobby electronics components. It further describes how to use the image analysis software package DeepLabCut to track the status of a strong light signal, as well as the position of a rat, in videos gathered from an operant conditioning chamber. The former is a great aid when selecting short segments of interest in videos that cover entire test sessions, and the latter enables analysis of parameters that cannot be obtained from the data logs produced by the operant chambers.
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| 2. |
- Espa, Elena, et al.
(författare)
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Seeding of protein aggregation causes cognitive impairment in rat model of cortical synucleinopathy
- 2019
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Ingår i: Movement Disorders. - : Wiley. - 0885-3185 .- 1531-8257. ; 34:11, s. 1699-1710
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cortical α-synuclein pathology plays a role in the development of cognitive dysfunction in both Parkinson's disease and dementia with Lewy bodies, although the causative cellular lesions have remained unclear. We aimed to address causal links between α-synuclein-driven pathology in the cerebral cortex and the development of cognitive impairments using new experimental models. Methods: Neuronal overexpression of human α-synuclein was induced in the rat medial prefrontal cortex using viral vectors. This was combined with inoculations of preformed fibrils of human α-synuclein in some animals. Rats were evaluated with tests probing prefrontal cognitive functions (delayed matching/nonmatching to position and 5-choice serial reaction time task). Patterns of neuropathology were characterized immunohistochemically. Results: Neither α-synuclein overexpression nor the fibril seeds alone yielded any behavioral phenotype. In contrast, combining the 2 approaches produced significant impairments in working memory, attention, and inhibitory control. All animals injected with α-synuclein vectors exhibited high immunoreactivity for human α-synuclein in the medial prefrontal cortex and its primary projection targets. However, only when this overexpression was combined with fibril inoculations did animals exhibit large, proteinase K-resistant and Ser129-phosphorylated α-synuclein intraneuronal inclusions in the medial prefrontal cortex and its closely interconnected brain regions. The inclusions were associated with distorted dendritic morphologies and partial neuronal loss in the targeted cortical areas. Conclusions: Cortical overexpression of human α-synuclein is not sufficient to produce cognitive dysfunction, whereas combining this overexpression with fibril seeds yields both cognitive and histopathological phenotypes that are relevant to human Lewy body disease.
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