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Noise-induced tuning curve changes in mechanoreceptors
C Ivey1, A V Apkarian, D R Chialvo
1Department of Neurosurgery, SUNY Health Sciences Center, Syracuse, New York 13210, USA.
Journal of Neurophysiology
|May 30, 1998
Summary
External noise enhances signal transmission in rat nerve fibers, broadening responses in rapidly adapting (RA) fibers and revealing stochastic resonance (SR) in both RA and slowly adapting (SA) fibers. This suggests noise is crucial for sensing environmental signals.
Area of Science:
- Neuroscience
- Sensory Physiology
- Biophysics
Background:
- Sensory perception models assume receptor tuning is stable in noisy environments.
- The role of external noise in modulating neural signal transmission is not fully understood.
Purpose of the Study:
- To investigate the effect of external noise on the signal transmission properties of rat tibial nerve fibers.
- To determine if noise enhances or degrades the ability of sensory receptors to detect periodic signals.
Main Methods:
- Recording single-unit spike activity from rat tibial nerve fibers (RA and SA units).
- Stimulating receptive fields with sine waves and varying levels of white noise.
- Quantifying signal-to-noise ratio (SNR) using the correlation coefficient (C1).
Main Results:
- Noise addition enhanced signal transmission in both RA and SA fibers.
- Increasing noise broadened and inverted tuning curves for RA fibers, expanding their responsive frequency range.
- SA fiber tuning curves remained invariant, but C1 increased with noise at higher frequencies.
- Responses exhibited rate modulation at low frequencies and stochastic resonance (SR) at higher frequencies.
Conclusions:
- External noise significantly alters the tuning properties of sensory receptors.
- Noise is relevant for sensing small periodic environmental signals, contrary to current sensory perception models.
- Receptor tuning in noisy environments differs from that measured in quiet conditions.