Skip to main content

Overabundance of a protein one of the causes of Parkinson’s disease: study (downtoearth)

Overabundance of a protein called alpha-synuclein has a key role in Parkinson’s disease, which affects more than 10 million people worldwide, says a study.

The study done by researchers at the Okinawa Institute of Science and Technology Graduate School (OIST) and is supposed to be published in Journal of Neuroscience says that overabundance of the protein in neuron play crucial role in development of the disease—the second most common neurodegenerative disorder after Alzheimer’s disease.

Parkinson’s disease results in declining physical functions, most noticeable of them being uncontrollable tremors. It involves malfunction and eventual death of the nerve cells in our brain. People with Parkinson’s disease also experience stiffness and cannot carry out movement as rapidly as before.

There is no cure for this disease and researchers have struggled for years to fully understand its cause.

Since 1990s, there has been an understanding that this particular protein causes the disease, but attempts at precisely finding its role in Parkinson’s have been unsuccessful until now.

Researchers have finally come with possible reason and role of this protein in the disease. They found that the protein hinders a key step involved in the transmission of neuronal signals essential for higher brain functions.

How does the protein affect?

Neurotransmission is a process that allows neurons to pass signals from one another, which is important for motor, sensory and cognitive functioning. When an electrical signal arrives at the nerve terminal and needs to be passed on to the next neuron, neurotransmitters (or chemical messengers) packed in a container made of lipid membrane called vesicle, mediate this process.

The neurotransmitter molecules are then released into the synaptic cleft—a small space between the neurons.

After being released, the neurotransmitter is received by the receptors in the adjacent neuron and the signal is passed along for further transmission and the vesicle is recycled back into the nerve terminal to be used again.

This retrieval of the empty vesicle membrane is called “endocytosis”, and it is this process that an overabundance of alpha-synuclein disrupts.

The process of endocytosis is critical for proper neurotransmission and when it is inhibited, the rest of the steps involved in transmission are affected as well.

Explainer: The white circles are empty vesicle and the blue ones contain a neurotransmitter. “Full” vesicles move toward the membrane of the nerve terminal, represented by the overall outline of the figure, where they attach and fuse into the terminal membrane, thereby releasing the transmitter into the space between neurons, the synaptic cleft. This release is illustrated by a blue omega-shaped structure at the bottom of the terminal membrane. When a vesicle becomes “empty,” the vesicle membrane is retrieved into the terminal—white circles on the right—and then recycled back to the release sites, which are illustrated as red bars.

“If you are using the vesicles mildly, this is okay, but if you start to use them heavily, then it becomes a problem,” explains OIST professor Tomoyuki Takahashi from the Cellular and Molecular Synaptic Function Unit.

Researchers believe that this inhibitory process caused by the overabundance of alpha-synuclein is what occurs in the early stages of Parkinson’s disease, before morphological changes such as loss of function and death of neurons take place.

When asked whether these results can help aid in developing treatment for Parkinson’s disease, Professor Takahashi replies: “I think we are getting close. We know the initial target and the mechanism but in order to step into the treatment stage, we should probably work a little bit more to know by what mechanism the microtubules interfere with endocytosis.”


Popular posts from this blog

Khar’s experimentation with Himalayan nettle brings recognition (downtoearth)

Nature never fails to surprise us. In many parts of the world, natural resources are the only source of livelihood opportunities available to people. They can be in the form of wild shrubs like Daphne papyracea and Daphne bholua (paper plant) that are used to make paper or Gossypium spp (cotton) that forms the backbone of the textile industry.

Nothing can compete with the dynamism of biological resources. Recently, Girardinia diversifolia (Himalayan nettle), a fibre-yielding plant, has become an important livelihood option for people living in the remote mountainous villages of the Hindu Kush Himalaya.

There is a community in Khar, a hamlet in Darchula district in far-western Nepal, which produces fabrics from Himalayan nettle. The fabric and the things made from it are sold in local as well as national and international markets as high-end products.

A Himalayan nettle value chain development initiative implemented by the Kailash Sacred Landscape Conservation and Development Initiati…

SC asks Centre to strike a balance on Rohingya issue (.hindu)

Supreme Court orally indicates that the government should not deport Rohingya “now” as the Centre prevails over it to not record any such views in its formal order, citing “international ramifications”.

The Supreme Court on Friday came close to ordering the government not to deport the Rohingya.

It finally settled on merely observing that a balance should be struck between humanitarian concern for the community and the country's national security and economic interests.

The court was hearing a bunch of petitions, one filed by persons within the Rohingya community, against a proposed move to deport over 40,000 Rohingya refugees. A three-judge Bench, led by Chief Justice of India Dipak Misra, began by orally indicating that the government should not deport Rohingya “now”, but the government prevailed on the court to not pass any formal order, citing “international ramifications”. With this, the status quo continues even though the court gave the community liberty to approach it in …

Cloud seeding

Demonstrating the function of the flare rack that carries silver iodide for cloud-seeding through an aircraft. 
Water is essential for life on the earth. Precipitation from the skies is the only source for it. India and the rest of Asia are dependent on the monsoons for rains. While the South West Monsoon is the main source for India as a whole, Tamil Nadu and coastal areas of South Andhra Pradesh get the benefit of the North East Monsoon, which is just a less dependable beat on the reversal of the South West Monsoon winds.