NOISE-ENHANCED INFORMATION-TRANSMISSION IN RAT SA1 CUTANEOUS MECHANORECEPTORS VIA APERIODIC STOCHASTIC RESONANCE

1. Aperiodic stochastic resonance (ASR) is a phenomenon wherein the re sponse of a nonlinear system to a weak aperiodic input signal is optim ized by the presence of a particular, nonzero level of noise. Our obje ctive was to demonstrate ASR experimentally in mammalian cutaneous mec hanoreceptors. 2. Experiments were performed on rat slowly adapting ty pe 1 (SA1) afferents. Each neuron was subjected to a perithreshold ape riodic stimulus plus noise. The variance of the noise was varied betwe en trials. The coherence between the aperiodic input stimulus and the response of each SA1 afferent was computed. 3. Of the 12 neurons teste d, 11 showed clear ASR behavior: as input noise variance was increased , the stimulus-response coherence rapidly increased to a peak and then slowly decreased. These findings were in contrast with those for the average firing rate, which increased monotonically as a function of in put noise variance. 4. This work shows that noise can serve to enhance the response of a sensory neuron to a perithreshold aperiodic input s ignal. These results suggest a possible functional role for input nois e in sensory systems. These findings also indicate that it may be poss ible to introduce noise artificially into sensory neurons to improve t heir abilities to detect arbitrary weak signals.