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
Pressure-volume curve: Elastic Recoil Pressure don't make sense
3 hours ago 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?
20 hours ago 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...
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013 As an experiment, for the past few months I've been consuming at least one portion of Jell-O or unflavored Knox gelatin per day. I'm 64, in very...
Alcohol and acetaminophen
May 13, 2013 Edit: sorry for the typo in the title , can't edit I looked around on google quite a bit and it's very hard to find precise information on the...
Marie Curie's leukemia
May 13, 2013 Does anyone know what might be the cause of Marie Curie's cancer
- More from Physics Forums - Medical Sciences
More news stories
For combat veterans suffering from post-traumatic stress disorder, 'fear circuitry' in the brain never rests
Chronic trauma can inflict lasting damage to brain regions associated with fear and anxiety. Previous imaging studies of people with post-traumatic stress disorder, or PTSD, have shown that these brain regions can over-or ...
Neuroscience 6 hours ago | not rated yet | 0 |
The neural machinery underlying our olfactory sense continues to be an enigma for neuroscience. A recent review in Neuron seeks to expand traditional ideas about how neurons in the olfactory bulb might encode information about ...
Neuroscience 17 hours ago | not rated yet | 0 |
(Medical Xpress)—What if the quality of your work depends more on your focus on the piano keys or canvas or laptop than your musical or painting or computing skills? If target users can be convinced, they ...
Neuroscience 17 hours ago | 3.7 / 5 (3) | 0 |
Neurological disorders can have a devastating impact on the lives of sufferers and their families.
Neuroscience 22 hours ago | 5 / 5 (1) | 0 |
If you're a left-brain thinker, chances are you use your right hand to hold your cell phone up to your right ear, according to a newly published study from Henry Ford Hospital in Detroit.
Neuroscience May 16, 2013 | 2 / 5 (2) | 0 |
Big names in medicine are set to give an upbeat assessment of the war on AIDS on Tuesday, 30 years after French researchers identified the virus that causes the disease.
5 hours ago | not rated yet | 0
In 2008 researchers from the University of Southern Denmark showed that the drug thioridazine, which has previously been used to treat schizophrenia, is also a powerful weapon against antibiotic-resistant bacteria such as ...
14 hours ago | 3.7 / 5 (3) | 0 |
Treatment for alcohol use disorders works best if the patient actively understands and incorporates the interventions provided in the clinic. Multiple factors can influence both the type and degree of neurocognitive abnormalities ...
15 hours ago | not rated yet | 0 |
In order to avoid harms associated with alcohol consumption, in 2009 the National Institute on Alcohol Abuse and Alcoholism issued guidelines that define low-risk drinking. These guidelines differ for men and women: no more ...
15 hours ago | not rated yet | 0 |
(Medical Xpress)—Working with lab mice models of multiple sclerosis (MS), UC Davis scientists have detected a novel molecular target for the design of drugs that could be safer and more effective than current FDA-approved ...
15 hours ago | 5 / 5 (2) | 0 |