Title
Slope-Based Stochastic Resonance: How Noise Enables Phasic Neurons To Encode Slow Signals
Abstract
Fundamental properties of phasic firing neurons are usually characterized in a noise-free condition. In the absence of noise, phasic neurons exhibit Class 3 excitability, which is a lack of repetitive firing to steady current injections. For time-varying inputs, phasic neurons are band-pass filters or slope detectors, because they do not respond to inputs containing exclusively low frequencies or shallow slopes. However, we show that in noisy conditions, response properties of phasic neuron models are distinctly altered. Noise enables a phasic model to encode low-frequency inputs that are outside of the response range of the associated deterministic model. Interestingly, this seemingly stochastic-resonance (SR) like effect differs significantly from the classical SR behavior of spiking systems in both the signal-to-noise ratio and the temporal response pattern. Instead of being most sensitive to the peak of a subthreshold signal, as is typical in a classical SR system, phasic models are most sensitive to the signal's rising and falling phases where the slopes are steep. This finding is consistent with the fact that there is not an absolute input threshold in terms of amplitude; rather, a response threshold is more properly defined as a stimulus slope/frequency. We call the encoding of low-frequency signals with noise by phasic models a slope-based SR, because noise can lower or diminish the slope threshold for ramp stimuli. We demonstrate here similar behaviors in three mechanistic models with Class 3 excitability in the presence of slow-varying noise and we suggest that the slope-based SR is a fundamental behavior associated with general phasic properties rather than with a particular biological mechanism.
Year
DOI
Venue
2010
10.1371/journal.pcbi.1000825
PLOS COMPUTATIONAL BIOLOGY
Keywords
Field
DocType
band pass filter,action potentials,signal to noise ratio,low frequency,conditioned response,stochastic processes,stochastic resonance
ENCODE,Biological system,Biology,Stochastic process,Subthreshold conduction,Deterministic system,Stochastic resonance,Stimulus (physiology),Genetics,Neuron,Amplitude
Journal
Volume
Issue
ISSN
6
6
1553-7358
Citations 
PageRank 
References 
3
0.45
7
Authors
3
Name
Order
Citations
PageRank
Yan Gai130.45
Brent Doiron216817.71
John Rinzel3459219.68