Breakdown of neural networks could help doctors track, better understand spread of Alzheimer's in brain
(Medical Xpress)—Scientists at Washington University School of Medicine in St. Louis have taken one of the first detailed looks into how Alzheimer's disease disrupts coordination among several of the brain's networks. The results, reported in The Journal of Neuroscience, include some of the earliest assessments of Alzheimer's effects on networks that are active when the brain is at rest.
"Until now, most research into Alzheimer's effects on brain networks has either focused on the networks that become active during a mental task, or the default mode network, the primary network that activates when a person is daydreaming or letting the mind wander," says senior author Beau Ances, MD, assistant professor of neurology. "There are, however, a number of additional networks besides the default mode network that become active when the brain is idling and could tell us important things about Alzheimer's effects."
Ances and his colleagues analyzed brain scans of 559 subjects. Some of these subjects were cognitively normal, while others were in the early stages of very mild to mild Alzheimer's disease. Scientists found that all of the networks they studied eventually became impaired during the initial stages of Alzheimer's.
"Communications within and between networks are disrupted, but it doesn't happen all at once," Ances says. "There's even one network that has a momentary surge of improved connections before it starts dropping again. That's the salience network, which helps you determine what in your environment you need to pay attention to."
Other networks studied by the researchers included:
- the dorsal attention network, which directs attention toward things in the environment that are salient;
- the control network, believed to be active in consciousness and decision-making; and
- the sensory-motor network, which integrates the brain's control of body movements with sensory feedback (e.g., did the finger that just moved strike the right piano key?).
The default mode network, previously identified as one of the first networks to be impaired by Alzheimer's, is a partner in two of the three pairs of anti-correlated networks scientist studied.
"While we can't prove this yet, one hypothesis is that as things go wrong in the processing of information in the default mode network, that mishandled data is passed on to other networks, where it creates additional problems," Ances says.
It's not practical to use these network breakdowns to clinically diagnose Alzheimer's disease, Ances notes, but they may help track the development of the disease and aid efforts to better understand its spread through the brain.
Ances plans to look at other markers for Alzheimer's disease in the same subjects, such as levels in the cerebrospinal fluid of amyloid beta, a major component of Alzheimer's plaques.
More information: Brier MR, Thomas JB, Snyder AZ, Benziger TL, Zhang D, Raichle ME, Holtzman DM, Morris JC, Ances BM. Loss of intranetwork and internetwork resting state functional connections with Alzheimer's progression. The Journal of Neuroscience, June 27, 2012. DOI:10.1523/JNEUROSCI.5698-11.2012
Journal reference: Journal of Neuroscience
- Brain's 'autopilot' provides insight into early development of Alzheimer's disease Jan 18, 2011 | not rated yet | 0
- Cells talk more in areas Alzheimer's hits first, boosting plaque component May 02, 2011 | not rated yet | 0
- Brain changes in people at genetic risk for Alzheimer's revealed in MRI scans Dec 15, 2010 | not rated yet | 0
- Alzheimer's plaques disrupt brain networks Apr 20, 2012 | not rated yet | 0
- Brain connectivity altered in type 2 diabetes Aug 01, 2012 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Why is zone 1 in liver more prone to ischemic injury?
May 23, 2013 Hi, Is it because around central vein, there is only deoxygenated blood from the vein where as in the periphery there is hepatic artery. Also why...
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013 As title suggest. Thanks :smile:
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013 Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
- More from Physics Forums - Medical Sciences
More news stories
New research presented today shows that formation of new neurons in the hippocampus - a brain region known for its importance in learning and remembering - could cause forgetting of old memories by causing a reorganization ...
Neuroscience May 24, 2013 | 4 / 5 (4) | 0
How can healthy people who hear voices help schizophrenics? Finding the answer for this is at the centre of research conducted at the University of Bergen.
Neuroscience May 24, 2013 | 4 / 5 (2) | 2
One of the major frontiers of modern science is a comprehensive understanding of the human brain and its functions to guide the development of new technologies in information and communication. In a major announcement for ...
Neuroscience May 24, 2013 | 3.7 / 5 (3) | 0
(Medical Xpress)—Regulating the distribution of power in neurons is done by a system that makes the national electric grid look simple by comparison. Each neuron has several thousand mitochondria confined ...
Neuroscience May 23, 2013 | 4.9 / 5 (9) | 0 |
(Medical Xpress)—The human brain is able to identify individuals' voices by comparing them against an internal 'average voice' prototype, according to neuroscientists.
Neuroscience May 23, 2013 | 3.7 / 5 (3) | 3 |
Coenzyme Q10 decreases all cause mortality by half, according to the results of a multicentre randomised double blind trial presented today at Heart Failure 2013 congress. It is the first drug to improve heart failure mortality ...
5 hours ago | 5 / 5 (1) | 4
Women at a particular stage in their monthly menstrual cycle may be more vulnerable to some of the psychological side-effects associated with stressful experiences, according to a study from UCL.
May 24, 2013 | 3.7 / 5 (3) | 4 |
Heart failure accelerates the aging process and brings on early andropausal syndrome (AS), according to research presented today at the Heart Failure Congress 2013. AS, also referred to as male 'menopause', was four times ...
5 hours ago | not rated yet | 1
Two mutations central to the development of infantile myofibromatosis (IM)—a disorder characterized by multiple tumors involving the skin, bone, and soft tissue—may provide new therapeutic targets, according to researchers ...
21 hours ago | 3 / 5 (2) | 0 |
(AP)—Department of Justice lawyers have again asked a federal appeals court in New York to delay lifting age restrictions and prescription requirements on an emergency contraceptive popularly known as the morning-after ...
5 hours ago | not rated yet | 0
Mortality and length of stay are highest in heart failure patients admitted in January, on Friday, and overnight, according to research presented today at the Heart Failure Congress 2013. The analysis of nearly 1 million ...
5 hours ago | not rated yet | 0