Investigations on Amyloid cascade hypothesis and Alzheimers disease progression on AD mouse models
Aim:This application covers Kentros lab's use of the genetically modified Alzheimers disease (AD) model mice to investigate the amyloid cascade hypothesis and AD progression upon gene manipulation in specific neuronal population in different regions of the brain. We plan to breed and use different AD mice models commercially available and also obtain from collaborators. These mice carries AD causing gene mutants like Amyloid precursor protein (APP), microtubule associated protein tau (MAPT) or Presenilin 1 (PSEN1) in central nervous system. These mutated genes lead to the Amyloid plaques and Tau tangles, which are the hallmarks of AD pathology.
Amyloid plaques and Tau tangles originates in specifc regions in brain and follows a neuronal circuitry. Amyloid cascade hypothesis, predicts that amyloid beta is the initiating trigger for the underlying causes of AD, such as Tau tangles, neurodegeneration and cogintive decline. Whether the amyloid plaque presursors/oligomers are transynaptically causing the underlying causes is debated. Our plan is to manipulate the Amyloid beta precursors in specific neurons and investigate the subsequent plaque, and tangle formation, in AD mice models. We will manipulate disease causing protein’s expression in specific neurons by a combinatorial approach of a breeding strategy with various neuron-specific transgenic lines and viral tools. We will knock down specific genes of interests using Adeno asociated viruses (AAV). This approach may help us to understand the involvement of specific neurons in the disease initiation and transynaptic progression.
Several mouse models for AD are commercially available. We don't know which strain will be most useful for the proposed long-term project. A widely used Transgenic AD model 3xTG-AD that expresses both the pathological correlates, namely plaques and tangles will be used. We will submit notifications for changes in this application if we start using other strains. For attaining the neuronal specificity, we will be cross breeding the AD mice with various transgenic lines that expresses tetracycline transactivator (tTA) in specific neurons.
3Rs:
Neuronal cell cultures, an in vitro model of a neural network, exist. However, these neurons in culture plate form random connections that in no way represent the precise connections that occur in the brain. Investigations at anatomical level is not possible with in vitro models. AD mice models display both plaque and tangle pathology. In vitro model for AD showing all these features is not available.
We use very sophisticated equipments to minimize the casualities during surgeries. Additionally, with the use a combinatorial approach of tTA mouse lines and AAVs by which we will be able to target specific cell types easily and precisely. These approaches will greatly reduce the number of animals required, as it gives greater anatomical specificity genetically.
Large cages, nesting material and a running wheel for exercise. This allows the mice to perform species-specific behaviours. We aim to house the animals in stable groups. The combination of different pain medications will ensure that pain is relieved at multiple levels to reduce any discomfort after surgery. Gas anesthesia is easy to adjust to obtain a balanced anesthesia throughout the procedure.
Amyloid plaques and Tau tangles originates in specifc regions in brain and follows a neuronal circuitry. Amyloid cascade hypothesis, predicts that amyloid beta is the initiating trigger for the underlying causes of AD, such as Tau tangles, neurodegeneration and cogintive decline. Whether the amyloid plaque presursors/oligomers are transynaptically causing the underlying causes is debated. Our plan is to manipulate the Amyloid beta precursors in specific neurons and investigate the subsequent plaque, and tangle formation, in AD mice models. We will manipulate disease causing protein’s expression in specific neurons by a combinatorial approach of a breeding strategy with various neuron-specific transgenic lines and viral tools. We will knock down specific genes of interests using Adeno asociated viruses (AAV). This approach may help us to understand the involvement of specific neurons in the disease initiation and transynaptic progression.
Several mouse models for AD are commercially available. We don't know which strain will be most useful for the proposed long-term project. A widely used Transgenic AD model 3xTG-AD that expresses both the pathological correlates, namely plaques and tangles will be used. We will submit notifications for changes in this application if we start using other strains. For attaining the neuronal specificity, we will be cross breeding the AD mice with various transgenic lines that expresses tetracycline transactivator (tTA) in specific neurons.
3Rs:
Neuronal cell cultures, an in vitro model of a neural network, exist. However, these neurons in culture plate form random connections that in no way represent the precise connections that occur in the brain. Investigations at anatomical level is not possible with in vitro models. AD mice models display both plaque and tangle pathology. In vitro model for AD showing all these features is not available.
We use very sophisticated equipments to minimize the casualities during surgeries. Additionally, with the use a combinatorial approach of tTA mouse lines and AAVs by which we will be able to target specific cell types easily and precisely. These approaches will greatly reduce the number of animals required, as it gives greater anatomical specificity genetically.
Large cages, nesting material and a running wheel for exercise. This allows the mice to perform species-specific behaviours. We aim to house the animals in stable groups. The combination of different pain medications will ensure that pain is relieved at multiple levels to reduce any discomfort after surgery. Gas anesthesia is easy to adjust to obtain a balanced anesthesia throughout the procedure.