Navigation Links
The brain's balancing act
Date:6/22/2014

Researchers at the University of California, San Diego School of Medicine have discovered a fundamental mechanism by which the brain maintains its internal balance. The mechanism, described in the June 22 advanced online publication of the journal Nature, involves the brain's most basic inner wiring and the processes that control whether a neuron relays information to other neurons or suppresses the transmission of information.

Specifically, the scientists have shown that there is a constant ratio between the total amount of pro-firing stimulation that a neuron receives from the hundreds or thousands of excitatory neurons that feed into it, and the total amount of red-light stop signaling that it receives from the equally numerous inhibitory neurons.

This constant ratio, called the E/I ration, was known to exist for individual neurons at a given time. This study goes a step further and shows that the E/I ratio is constant across multiple neurons in the cortex of mice and likely also humans, since the fundamental architecture of mammalian brains is highly conserved across species.

"Neurons in our brain drive by pushing the brake and the accelerator at the same time," said Massimo Scanziani, PhD, professor of neurosciences, Howard Hughes Medical Institute investigator and co-author. "This means that there is no stimulus that you can apply that will activate purely excitatory neurons or purely inhibitory ones."

"There is always a tug-of-war. It's weird but very clever. It allows the brain to exert very subtle control on our response to stimuli." For example, Scanziani said it prevents both runaway neuronal firing (excitation) and permanent quiescence (inhibition) because excitation and inhibition are always coupled.

In experiments, the scientists also showed how the brain maintains a constant E/I ratio across neurons: The adjustment is carried out by the inhibitory neurons through the appropriate strengthening or weakening of inhibitory synapses. A synapse is the gap or juncture between two neurons and synaptic strength refers to the degree to which a passed signal is amplified in the juncture.

"Our study shows that the inhibitory neurons are the master regulators that contact hundreds or thousands of cells and make sure that the inhibitory synapses at each of these contacts is matched to the different amounts of excitation that these cells are receiving," Scanziani explained. If, for example, the level of excitatory stimulation that a nerve cell is receiving is doubled, the inhibitory synapses over a period of a few days will also double their strength.

In terms of clinical applications, the scientists said that neurological diseases such as autism, epilepsy and schizophrenia are believed to be a problem, at least in part, of the brain's ability to maintain an optimal E/I ratio.

"If this E/I balance is broken, it completely alters your perception of the world," Scanziani said. "You will be less able to adjust and adapt appropriately to the range of stimulation in a normal day without being overwhelmed or completely oblivious, and E/I imbalances may be most easily noticed in social interactions because these interactions require such nuance and subtle adjusting."

Scientists have also proposed that some neurodegenerative diseases, such as Parkinson's and Huntington's disease, may be associated with a shift in the E/I balance.

Minghan Xue, a postdoctoral researcher in neurobiology and the study's lead author, said "now that we know how this E/I balance is regulated in a normal brain, we can begin to understand what goes wrong in the diseased state. It paves the way for interventions that might restore the balance in the brain."


'/>"/>
Contact: Scott LaFee
619-543-6163
University of California - San Diego
Source:Eurekalert  

Related medicine news :

1. Study finds difference in way bipolar disorder affects brains of children versus adults
2. Understanding the unique nature of childrens bodies and brains
3. MRI shows disrupted connections in the brains of young people with ADHD
4. Brainstem discovered as important relay site after stroke
5. Worker wasps grow visual brains, queens stay in the dark
6. MR spectroscopy shows differences in brains of preterm infants
7. RSNA: MR Spectroscopy Shows Differences in Brains of Preterm Infants
8. Hollywood Panel Says, "Ladies, Twerk Your Brains and Values...not Your Booty!"
9. Ballet dancers brains adapt to stop them getting in a spin
10. 2nd Annual Brains Matter Conference Brings Together National Brain Tumor Experts to the Pacific Northwest
11. Research Shows How Ritalin Affects Brains of Kids With ADHD
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
The brain's balancing act
(Date:1/20/2017)... ... ... Christmas:” a beautiful and enchanting tale that teaches children the true meaning of Christmas. “Journey ... Oklahoma City, and a devoted woman of faith. , “Becoming a parent changes you. ... of my mind for years, but actually doing it might have been a while in ...
(Date:1/19/2017)... ... ... the Centers for Medicare & Medicaid Services (CMS) announced over 359,000 clinicians are ... who participate in APMs are paid for the quality of care they give to ... a system that delivers better care and one in which clinicians work together to ...
(Date:1/19/2017)... ... 2017 , ... With the cold weather here, many people will have to clear snow with ... large amounts of snow, but they can be dangerous when used incorrectly. That’s why ... for the proper use of snow blowers:, , When removing wet ...
(Date:1/19/2017)... ... January 19, 2017 , ... ... solutions, has recently unveiled impressive transportable capabilities with their iMedHD2™ Portable Teleultrasound ... an extension to RMT technology that delivers HD, dynamic, streaming ultrasound images and ...
(Date:1/19/2017)... NJ (PRWEB) , ... January 19, 2017 , ... ... certified dermatologist by the American Board of Dermatology and fellowship trained Mohs and ... the National Institutes of Health, Dr. Li completed his internship in internal medicine ...
Breaking Medicine News(10 mins):
(Date:1/20/2017)... 20, 2017 Avillion LLP, a co-developer and ... Mark Weinberg , MD MBA as Chief Medical Officer. Dr Weinberg ... USA . ... Dr Weinberg has spent more than 17 years as a pharmaceutical ... to micro-cap biotech. Over the course of his career, he has ...
(Date:1/19/2017)... -- Report Details What can be expected ... to grow at the fastest rates? This visiongain report ... opportunities and prospects. Our 190-page report provides 124 ... in the industry and the future market prospects. Our ... all the major categories of the ophthalmic devices market. ...
(Date:1/19/2017)... -- Conference Call and Webcast to Follow Vanda Pharmaceuticals ... release results for the fourth quarter of 2016 on Wednesday, February ... ... 4:30 PM ET on Wednesday, February 15, 2017, during which management ... and other corporate activities. To participate in the conference call, please ...
Breaking Medicine Technology: