Scientists discover protein's role in human memory and learning functions

February 19, 2014, Biomedical Sciences Institutes

Scientists at A*STAR's Institute of Molecular and Cell Biology (IMCB) have identified the precise role of the protein, SNX27, in the pathway leading to memory and learning impairment. The study broadens the understanding of the brain's memory function and could be used to explain defects in the cognitive development of those with Down's syndrome. The newly established knowledge could potentially facilitate exploration of strategies to improve memory and learning abilities in Down's syndrome.

Down's syndrome is a genetic condition characterized by the presence of an additional copy of chromosome 21. About one in eight hundred new-borns is diagnosed with Down's syndrome. It is a condition that leads to impairments in both cognitive ability and physical growth that range from mild to moderate developmental disabilities. Yet, there is still no treatment for it.

In an earlier study published in Nature Medicine, an international team of scientists discovered that the additional copy of chromosome 21 in Down's syndrome reduces the production of SNX27 in the brain and results in synaptic dysfunction. Synapse, a structure that permits to pass to each other, is known to have an important role in formation and its dysfunction could result in impairment. By re-introducing SNX27 into the brain, memory could be restored hence suggesting that SNX27 is an essential protein for memory and learning.

The protein's role in the pathway leading to , however, remained unclear until scientists from IMCB utilised live-cell imaging techniques to elucidate the mechanism of memory impairment and illustrated how SNX27 attributes to synaptic dysfunction. The scientists observed that transmission of chemical signals between the nerve cells are facilitated by AMPA-receptors and the activity occurs on the brain cell surface. As SNX27 plays an important role in shuttling the AMPA-receptor to the brain cell surface, lower levels of SNX27 means fewer receptors are carried to the surface, which consequently interrupts the signal transmission and impairs memory. This discovery was reported in the 24 January, 2014 issue of the renowned scientific journal, Nature Communications.

The correlation established between SNX27 levels and memory could explain why individuals with Down's syndrome encounter memory and learning difficulties. Identifying the target and its role is a crucial first step to therapy – having known the role of SNX27 in memory impairment, future research on Down's syndrome could focus on developing strategies which can effectively re-introduce the protein into the brain to restore memory and learning abilities.

Dr Loo Li Shen was an A*STAR scholar who is now working with Executive Director of IMCB, Prof Wanjin Hong, and is also an adjunct Assistant Professor at LKC medical school of NTU. The lead author of the Nature Communications paper and co-author of the Nature Medicine paper said, "Memory and the ability to learn capture the essence of life. Our research goes beyond the lab to make a difference by finding ways to grant these fundamental capabilities to those diagnosed with Down's syndrome. Our ultimate goal is to create a positive impact on the lives of these valuable children."

Prof Hong added, "In IMCB, we conduct research that would contribute to our understanding of mankind. This is a good example where the study is directed at a human condition - the Down's syndrome. The knowledge established from the findings could potentially translate into treatments for Down's syndrome or even become applicable to other similar human conditions."

Explore further: Researchers unravel molecular roots of Down syndrome

More information: Full text of the Nature Communications article can be accessed from www.nature.com/ncomms/2014/140 … full/ncomms4176.html Full text of the Nature Medicine article can be accessed from www.nature.com/nm/journal/v19/n4/full/nm.3117.html

Related Stories

Researchers unravel molecular roots of Down syndrome

March 24, 2013
Sanford-Burnham researchers discover that the extra chromosome inherited in Down syndrome impairs learning and memory because it leads to low levels of SNX27 protein in the brain.

Further potential insight into the complex neuropathology of Down's syndrome

April 8, 2013
(Medical Xpress)—Researchers at the University of Bristol have revealed new insight into the function of a key protein attributed to impaired learning and memory in Down's syndrome. The findings, published online in Nature ...

Lithium restores cognitive function in Down syndrome mice

December 3, 2012
Down syndrome is a neurodevelopmental disorder that is the leading cause of genetically defined intellectual disability. In the brain, Down syndrome results in alterations in the connections between neurons and a reduction ...

Infections damage our ability to form spatial memories

January 24, 2014
Increased inflammation following an infection impairs the brain's ability to form spatial memories – according to new research. The impairment results from a decrease in glucose metabolism in the brain's memory centre, ...

Mechanism in Alzheimer's-related memory loss identified

January 19, 2014
Cleveland Clinic researchers have identified a protein in the brain that plays a critical role in the memory loss seen in Alzheimer's patients, according to a study to be published in the journal Nature Neuroscience and posted ...

Gender influences symptoms of genetic disorder

February 7, 2014
(Medical Xpress)—A genetic disorder that affects about 1 in every 2,500 births can cause a bewildering array of clinical problems, including brain tumors, impaired vision, learning disabilities, behavioral problems, heart ...

Recommended for you

Your brain responses to music reveal if you're a musician or not

January 23, 2018
How your brain responds to music listening can reveal whether you have received musical training, according to new Nordic research conducted in Finland (University of Jyväskylä and AMI Center) and Denmark (Aarhus University).

New neuron-like cells allow investigation into synthesis of vital cellular components

January 22, 2018
Neuron-like cells created from a readily available cell line have allowed researchers to investigate how the human brain makes a metabolic building block essential for the survival of all living organisms. A team led by researchers ...

Finding unravels nature of cognitive inflexibility in fragile X syndrome

January 22, 2018
Mice with the genetic defect that causes fragile X syndrome (FXS) learn and remember normally, but show an inability to learn new information that contradicts what they initially learned, shows a new study by a team of neuroscientists. ...

Epilepsy linked to brain volume and thickness differences

January 22, 2018
Epilepsy is associated with thickness and volume differences in the grey matter of several brain regions, according to new research led by UCL and the Keck School of Medicine of USC.

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.