Noise down, neuron signals up

Aug 15, 2012

Biomedical engineer Muhammet Uzuntarla from Bulent Ecevit University, Turkey, and his colleagues present a biologically accurate model of the underlying noise which is present in the nervous system. The article is about to be published in European Physical Journal B. This work has implications for explaining how noise, modulated by unreliable synaptic transmission, induces a delay in the response of neurons to external stimuli as part of the neurons coding mechanism.

Neurons communicate by means of electrical pulses, called spikes, exchanged via synapses. The time it takes for to first respond to an external stimulus with an —commonly referred to as fist-spike latency—is of particular interest for scientists. It is thought to carry much more neural information than subsequent serial spike signals.

The authors analysed the presence of noise in the nervous system detected through changes in first-spike latency. The noise is due to the synaptic bombardment of each neuron by a large number of incoming excitatory and inhibitory spike inputs. Previous attempts at noise modeling used a generic bell-shaped signal, referred to as a Gaussian approximation. Now, Uzuntarla and his colleagues have devised a noise model that is closer to the biological reality.

They showed there is a relation between the noise and delays in spike signal transmission. The latter is caused by unreliable synapses that do not always transmit the signal, because their chemical-based signalling does not always work. Yet, the authors also demonstrated that synaptic unreliability can be controlled.

To do so, they identified two factors that could be tuned influencing the noise, namely the incoming excitatory and inhibitory input signalling regime and the coupling strength between inhibitory and excitatory . Ultimately, the authors concluded, modulating these factors could help encode information more accurately.

Explore further: Better thermal-imaging lens from waste sulfur

More information: M. Uzuntarla et al. (2012). Controlling the First-Spike Latency Response of a Single Neuron via Unreliable Synaptic Transmission, European Physical Journal B; DOI 10.1140/epjb/e2012-30282-0

add to favorites email to friend print save as pdf

Related Stories

Control of brain waves from the brain surface

Jun 15, 2012

Whether or not a neuron transmits an electrical impulse is a function of many factors. European research is using a heady mixture of techniques – molecular, microscopy and electrophysiological – ...

Role of noise in neurons

May 04, 2007

Addressing a current issue in neuroscience, Aldo Faisal and Simon Laughlin from Cambridge University investigate the reliability of thin axons for transmitting information. They show that noise effects in ion channels in ...

Zinc plays important role in brain circuitry

Nov 22, 2006

To the multitude of substances that regulate neuronal signaling in the brain and spinal cord add a new key player: zinc. By engineering a mouse with a mutation affecting a neuronal zinc target, researchers have demonstrated ...

Balancing connections for proper brain function

Jun 22, 2012

Neuropsychiatric conditions such as autism, schizophrenia and epilepsy involve an imbalance between two types of synapses in the brain: excitatory synapses that release the neurotransmitter glutamate, and ...

Random noise helps make signals clearer

Dec 06, 2011

Scientists have shown the energy conditions, under which a weak signal supplied to a physical system emerges as a stronger signal at the output thanks to the presence of random noise (a process known as stochastic resonance), ...

Recommended for you

Could 'Jedi Putter' be the force golfers need?

1 hour ago

Putting is arguably the most important skill in golf; in fact, it's been described as a game within a game. Now a team of Rice engineering students has devised a training putter that offers golfers audio, ...

Better thermal-imaging lens from waste sulfur

16 hours ago

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

User comments : 0

More news stories

Could 'Jedi Putter' be the force golfers need?

Putting is arguably the most important skill in golf; in fact, it's been described as a game within a game. Now a team of Rice engineering students has devised a training putter that offers golfers audio, ...

Under some LED bulbs whites aren't 'whiter than white'

For years, companies have been adding whiteners to laundry detergent, paints, plastics, paper and fabrics to make whites look "whiter than white," but now, with a switch away from incandescent and fluorescent lighting, different ...