PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

UNC neuroscientists discover new 'mini-neural computer' in the brain

2013-10-28
(Press-News.org) Contact information: Mark Derewicz
mark.derewicz@unch.unc.edu
919-923-0959
University of North Carolina Health Care
UNC neuroscientists discover new 'mini-neural computer' in the brain

CHAPEL HILL, N.C. – Dendrites, the branch-like projections of neurons, were once thought to be passive wiring in the brain. But now researchers at the University of North Carolina at Chapel Hill have shown that these dendrites do more than relay information from one neuron to the next. They actively process information, multiplying the brain's computing power.

"Suddenly, it's as if the processing power of the brain is much greater than we had originally thought," said Spencer Smith, PhD, an assistant professor in the UNC School of Medicine.

His team's findings, published October 27 in the journal Nature, could change the way scientists think about long-standing scientific models of how neural circuitry functions in the brain, while also helping researchers better understand neurological disorders.

"Imagine you're reverse engineering a piece of alien technology, and what you thought was simple wiring turns out to be transistors that compute information," Smith said. "That's what this finding is like. The implications are exciting to think about."

Axons are where neurons conventionally generate electrical spikes, but many of the same molecules that support axonal spikes are also present in the dendrites. Previous research using dissected brain tissue had demonstrated that dendrites can use those molecules to generate electrical spikes themselves, but it was unclear whether normal brain activity involved those dendritic spikes. For example, could dendritic spikes be involved in how we see?

The answer, Smith's team found, is yes. Dendrites effectively act as mini-neural computers, actively processing neuronal input signals themselves.

Directly demonstrating this required a series of intricate experiments that took years and spanned two continents, beginning in senior author Michael Hausser's lab at University College London, and being completed after Smith and Ikuko Smith, PhD, DVM, set up their own lab at the University of North Carolina. They used patch-clamp electrophysiology to attach a microscopic glass pipette electrode, filled with a physiological solution, to a neuronal dendrite in the brain of a mouse. The idea was to directly "listen" in on the electrical signaling process.

"Attaching the pipette to a dendrite is tremendously technically challenging," Smith said. "You can't approach the dendrite from any direction. And you can't see the dendrite. So you have to do this blind. It's like fishing if all you can see is the electrical trace of a fish." And you can't use bait. "You just go for it and see if you can hit a dendrite," he said. "Most of the time you can't."

But Smith built his own two-photon microscope system to make things easier.

Once the pipette was attached to a dendrite, Smith's team took electrical recordings from individual dendrites within the brains of anesthetized and awake mice. As the mice viewed visual stimuli on a computer screen, the researchers saw an unusual pattern of electrical signals – bursts of spikes – in the dendrite.

Smith's team then found that the dendritic spikes occurred selectively, depending on the visual stimulus, indicating that the dendrites processed information about what the animal was seeing.

To provide visual evidence of their finding, Smith's team filled neurons with calcium dye, which provided an optical readout of spiking. This revealed that dendrites fired spikes while other parts of the neuron did not, meaning that the spikes were the result of local processing within the dendrites.

Study co-author Tiago Branco, PhD, created a biophysical, mathematical model of neurons and found that known mechanisms could support the dendritic spiking recorded electrically, further validating the interpretation of the data.

"All the data pointed to the same conclusion," Smith said. "The dendrites are not passive integrators of sensory-driven input; they seem to be a computational unit as well."

His team plans to explore what this newly discovered dendritic role may play in brain circuitry and particularly in conditions like Timothy syndrome, in which the integration of dendritic signals may go awry.



INFORMATION:



Study co-authors were Ikuko Smith, PhD, DVM, Tiago Branco, PhD, and Michael Häusser, PhD. This work was supported by a Long-Term Fellowship and a Career Development Award from the Human Frontier Science Program, and a Klingenstein Fellowship to S. Smith, a Helen Lyng White Fellowship to I. Smith, a Wellcome Trust and Royal Society Fellowship, and Medical Research Council (UK) support to T. Branco, and grants from the Wellcome Trust, the European Research Council, and Gatsby Charitable Foundation to M. Häusser.



ELSE PRESS RELEASES FROM THIS DATE:

International collaboration finds 11 new Alzheimer's genes to target for drug discovery

2013-10-28
International collaboration finds 11 new Alzheimer's genes to target for drug discovery Study yields fresh look at role of immune system in Alzheimer's MIAMI -- University of Miami Miller School of Medicine researchers played a key role in the largest international ...

Study with totally blind people shows how light helps activate the brain

2013-10-28
Study with totally blind people shows how light helps activate the brain This news release is available in French. Light enhances brain activity during a cognitive task even in some people who are totally blind, according to a study conducted ...

Bird buffet requires surveillance

2013-10-28
Bird buffet requires surveillance Sandpipers exhibit different feeding behavior depending on position in group The behaviour of semipalmated sandpipers (Calidris pusilla) feeding during low tide in the Bay of Fundy, New Brunswick, surprised Guy ...

Can the 'right' helmet prevent concussions?

2013-10-28
Can the 'right' helmet prevent concussions? Study finds no difference in concussion risk among high school football players using different brands and ages of helmets; custom mouth guards do not reduce risk ORLANDO, Fla. – While many football helmet and mouth ...

Sports specialization, hours spent in organized sports may predict young athlete injury

2013-10-28
Sports specialization, hours spent in organized sports may predict young athlete injury Children spend nearly twice the amount of time in organized sports than in free play ORLANDO, Fla. – Athletes ages 8 to 18 who spend twice as many hours per week in organized ...

Can pediatricians successfully promote safe driving agreements between teens and parents?

2013-10-28
Can pediatricians successfully promote safe driving agreements between teens and parents? New study looks at pediatricians promoting CheckpointsTM safe driving program to parents ORLANDO, Fla. –Motor vehicle crashes are the leading cause of death among teens. ...

Protecting children from firearm violence

2013-10-28
Protecting children from firearm violence Study documents differences in the types of injuries and how children arrive at the hospital based on age, and illustrates important gaps in data collection ORLANDO, Fla. – Firearm-related injuries in children ...

New technology optimizes ear infection diagnosis and management

2013-10-28
New technology optimizes ear infection diagnosis and management Smartphone-enabled otoscope provides clear, transmittable images of the ear drum ORLANDO, Fla. – A new, smartphone-enabled otoscope provides clear, transmittable images of the ear drum, or tympanic ...

Measuring segments of genetic material may help predict and monitor recurrence after thyroid cancer

2013-10-28
Measuring segments of genetic material may help predict and monitor recurrence after thyroid cancer A new analysis has found that the presence of short segments of genetic material (known as microRNA) within papillary thyroid cancer tumors suggests a likelihood of recurrence after patients ...

Early skin-to-skin contact linked to higher breastfeeding rates

2013-10-28
Early skin-to-skin contact linked to higher breastfeeding rates Rates higher when skin-to-skin is contact combined with mother's intent to breastfeed exclusively ORLANDO, Fla. -- Skin-to-skin contact between mother and infant in the delivery room is associated ...

LAST 30 PRESS RELEASES:

Early diagnosis of bladder cancer, now conveniently at home

People who are autistic and transgender/gender diverse have poorer health and health care

Gene classifier tests for prostate cancer may influence treatment decisions despite lack of evidence for long-term outcomes

KERI, overcomes the biggest challenge of the lithium–sulfur battery, the core of UAM

In chimpanzees, peeing is contagious

Scientists uncover structure of critical component in deadly Nipah virus

Study identifies benefits, risks linked to popular weight-loss drugs

Ancient viral DNA shapes early embryo development

New study paves way for immunotherapies tailored for childhood cancers

Association of waist circumference with all-cause and cardiovascular mortalities in diabetes from the National Health and Nutrition Examination Survey 2003–2018

A new chapter in Roman administration: Insights from a late Roman inscription

Global trust in science remains strong

New global research reveals strong public trust in science

Inflammation may explain stomach problems in psoriasis sufferers

Guidance on animal-borne infections in the Canadian Arctic

Fatty muscles raise the risk of serious heart disease regardless of overall body weight

HKU ecologists uncover significant ecological impact of hybrid grouper release through religious practices

New register opens to crown Champion Trees across the U.S.

A unified approach to health data exchange

New superconductor with hallmark of unconventional superconductivity discovered

Global HIV study finds that cardiovascular risk models underestimate for key populations

New study offers insights into how populations conform or go against the crowd

Development of a high-performance AI device utilizing ion-controlled spin wave interference in magnetic materials

WashU researchers map individual brain dynamics

Technology for oxidizing atmospheric methane won’t help the climate

US Department of Energy announces Early Career Research Program for FY 2025

PECASE winners: 3 UVA engineering professors receive presidential early career awards

‘Turn on the lights’: DAVD display helps navy divers navigate undersea conditions

MSU researcher’s breakthrough model sheds light on solar storms and space weather

Nebraska psychology professor recognized with Presidential Early Career Award

[Press-News.org] UNC neuroscientists discover new 'mini-neural computer' in the brain