Author: Megumi Mori

The Parkinsonian Brain: Cellular Senescence and Neurodegeneration

Parkinson’s Disease (PD) is the second most common age-related neurological disorder in the US. Many genetic factors that contribute to an increased risk of developing PD have been identified over the years. These include mutations in the α-synuclein and Parkin genes. Additionally, epidemiology studies show increased risk of PD after exposure to pesticides and organic pollutants, as well as heavy metals. However, recent research shows that aging is a major player in the development of PD. Key clinical features of PD are impairments in motor activities including difficulty initiating voluntary movement, loss of facial expression (masked faces), and smaller...

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The Aging Brain: Synaptic Regulation and Aging

Our brain is constantly changing, adjusting to the environment based on input. At the same time, there seems to be mechanisms in place to resist change. At the junctions between neurons and their targets, known as “synapses”, there are mechanisms to ensure that the amount of signal sent from neurons and the sensitivity of the target cells are in constant balance. There is increased interest in how this homeostatic mechanism changes with age, as disruption in synaptic homeostasis may be causal to disease. Hence it may be possible to increase lifespan via interventions that restore optimal activity of synapses. Drosophila melanogaster (fruit fly) is an attractive model organism for looking at synaptic regulation. Many of the genes involved in synaptic transmission and development are conserved between the fly and vertebrates. The neuromuscular junctions (synaptic formation between motor neurons and muscle cells) are easy to identify, and allow for direct recording of electrical activity in neurons and in muscle. An added bonus is the ability to genetically manipulate the post-synaptic cell separately from the presynaptic cell (and vice versa), thanks to availability of genetic switches specific to the muscle and the neuron. In 2012, Dr. Pejmun Haghighi’s lab at the Buck Institute reported the role of TOR (target of rapamycin), a well-known gene in the aging field, in synaptic regulation. Normally, flies lacking a component of the glutamate receptor in...

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