Computational intelligence opens up new avenues in Alzheimer's research

October 9, 2012
Reconstruction of granule neurons (left). Granule neurons are estimated to account for 80% of dentate gyrus neurons. By contrast, pyramidal neurons are the most common neurons in the entorhinal cortex. Pyramidal neurons are the group most at risk from lesion in Alzheimer's disease. Credit: Facultad de Informática, UPM.

Researchers from the Computational Intelligence Group based at the Universidad Politécnica de Madrid's Facultad de Informática have used machine learning and data mining techniques to compare gene expresssion levels in Alzheimer's disease (AD) patients in two key regions of the hippocampus: the dentate gyrus, where the disease appears to have little or no effect, and the entorhinal cortex, where Alzheimer's disease produces major neuronal damage.

The results, published in Computer Methods and Programs in Biomedicine, corroborate previous findings by other studies and set forth new working hypotheses for AD research.

Dentate gyrus and entorhinal cortex

The hippocampal formation is a complex structure situated in the medial temporal lobe of the brain. It plays a key role in memory, attention and . It is composed of six regions: presubiculum, subiculum, parasubiculum, , hippocampus and entorhinal cortex. A noteworthy part of this formation is the dentate gyrus, one of the few regions of the brain where new neurons continue to be born (neurogenesis) throughout adulthood. It is known that neurogenesis plays a key role in the generation of . Postmortem histopathological studies have provided evidence that the dentate gyrus is the least affected by AD.

The entorhinal cortex is the primary interface between the hippocampus and the neocortex. This region plays a key role in and consolidation, as well as the retrieval of autobiographical, declarative and . Today, we know that the entorhinal cortex is not only one of the first areas to be affected by AD but also where its progression produces most lesions.

Data analysis using an ensemble of Bayesian classifiers

The data mining technique used is part of the computational intelligence discipline. Thanks to the computational power available today, vast amounts of complex data can be analysed holistically to identify new findings or set forth new hypotheses. This study has used ensemble statistical techniques applied to mathematical models to search for relevant genes and gene dependency networks. In both cases, the mathematical paradigm used is called Bayesian classifier.

Results

The results identify relevant genes in different neurological diseases, as well as key metabolic mechanisms that corroborate earlier molecular research in AD. One of these findings is the deregulation of the DEC1 and BTRC genes that help to regulate the molecular clock controlling the body's circadian rhythm.

One of the most common symptoms of AD is sleep disorder, an effect of the loss of the circadian reference. Patients' brains do not correctly identify when they should sleep or be awake. Sleepless periods increase amyloid beta levels, causing the disease to progress.

Another noteworthy result is the deregulation of the S100A10 gene. This gene plays a key role in serotonin receptors, whose activity is linked to neuropsychiatric symptoms in AD patients.

Similarly, it is known to be involved in the pathogenesis and deregulation of depressive disorders. The level of this gene's differential activity between the dentate gyrus and corroborates both these associations and recent findings identifying it as a new early biomarker of AD.

Explore further: Sleeping brain behaves as if it's remembering something, study shows

More information: Armañanzas, R., Larrañaga, P. & Bielza, C. (2012). Ensemble transcript interaction networks: A case study on Alzheimer's disease. Computer Methods and Programs in Biomedicine, 108(1), 442-450.

Related Stories

Sleeping brain behaves as if it's remembering something, study shows

October 7, 2012
UCLA researchers have for the first time measured the activity of a brain region known to be involved in learning, memory and Alzheimer's disease during sleep. They discovered that this part of the brain behaves as if it's ...

Brain circuits connected with memory discovered

November 7, 2011
(Medical Xpress) -- A new study published last week in Science reveals the discovery of a brain pathway that helps us link events that happen close together and play a role in memories.

Recommended for you

Canola oil linked to worsened memory and learning ability in Alzheimer's

December 7, 2017
Canola oil is one of the most widely consumed vegetable oils in the world, yet surprisingly little is known about its effects on health. Now, a new study published online December 7 in the journal Scientific Reports by researchers ...

Genetics study suggests that education reduces risk of Alzheimer's disease

December 7, 2017
The theory that education protects against Alzheimer's disease has been given further weight by new research from the University of Cambridge, funded by the European Union. The study is published today in the BMJ.

Healthy mitochondria could stop Alzheimer's

December 6, 2017
Alzheimer's disease is the most common form of dementia and neurodegeneration worldwide. A major hallmark of the disease is the accumulation of toxic plaques in the brain, formed by the abnormal aggregation of a protein called ...

Alzheimer's damage in mice reduced with compound that targets APOE gene

December 6, 2017
People who carry the APOE4 genetic variant face a substantial risk for developing Alzheimer's disease.

Lithium in water associated with slower rate of Alzheimer's disease deaths

December 5, 2017
Rates of diabetes and obesity, which are important risk factors for Alzheimer's disease, also decrease if there is a particular amount of lithium in the water, says the study, published recently in the Journal of Alzheimer's ...

Hyperbaric oxygen therapy may alleviate symptoms of Alzheimer's Disease

December 5, 2017
A new Tel Aviv University study reveals that hyperbaric oxygen treatments may ameliorate symptoms experienced by patients with Alzheimer's disease.

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.