Noise Enhances Action Potential Generation in Mouse Sensory Neurons via Stochastic Resonance

Abstract

Noise can enhance perception of tactile and proprioceptive stimuli by stochastic resonance processes. However, the mechanisms underlying this general phenomenon remain to be characterized. Here we studied how externally applied noise influences action potential firing in mouse primary sensory neurons of dorsal root ganglia, modelling a basic process in sensory perception. Since noisy mechanical stimuli may cause stochastic fluctuations in receptor potential, we examined the effects of sub-threshold depolarizing current steps with superimposed random fluctuations. We performed whole cell patch clamp recordings in cultured neurons of mouse dorsal root ganglia. Noise was added either before and during the step, or during the depolarizing step only, to focus onto the specific effects of external noise on action potential generation. In both cases, step + noise stimuli triggered significantly more action potentials than steps alone. The normalized power norm had a clear peak at intermediate noise levels, demonstrating that the phenomenon is driven by stochastic resonance. Spikes evoked in step + noise trials occur earlier and show faster rise time as compared to the occasional ones elicited by steps alone. These data suggest that external noise enhances, via stochastic resonance, the recruitment of transient voltage-gated Na channels, responsible for action potential firing in response to rapid step-wise depolarizing currents.

Stochastic resonance enhances the rate of evidence accumulation during combined brain stimulation and perceptual decision-making

“…Although the underlying neural mechanisms are not completely understood [ 19 ], single unit recordings in visual cortex have revealed an increase in the SNR of neuronal spiking when an optimal level of noise is applied to a visual stimulus [ 20 ], consistent with a stochastic resonance mechanism. This is likely due to the recruitment of voltage-gated sodium channels by the noise [ 21 – 23 ]. Our previous study [ 18 ], together with several related investigations [ 24 , 25 ], point to stochastic resonance as an underlying mechanism by which non-invasive brain stimulation can enhance behavioural performance when it is applied concurrently during task performance.…”

Making up your mind: Enhanced perceptual decision-making induced by stochastic resonance during non-invasive brain stimulation: Stochastic resonance in perceptual decision-making

“…However, single unit recordings have shown that sensory neurons in the visual cortex are sensitive to a stochastic resonance mechanism, e.g., there is an increase in the SNR of the firing rate of neurons when an optimal level of noise is applied to a visual stimulus [44]. This is likely due to the recruitment of voltage-gated sodium channels by the noise [45-47].…”

Transcranial Random Noise Stimulation acutely lowers the response threshold of human motor circuits

“…100 V/m; Roth et al 1991Roth et al , 2007. By contrast, detrimental effects of noise on signal detection demonstrated in vitro, usually requires noise amplitudes which are in the same order or larger than the activation stimulus (see for example Onorato et al 2016).…”

“…Even though the neurophysiological mechanism of tRNS is not completely understood, it has been demonstrated that electrical random noise increases action potential firing in primary sensory neurons of dorsal root ganglia (Onorato et al 2016). The authors suggested that such enhancement occurred by the concurrent activation of voltage-gated sodium channels mediated by the SR phenomenon.…”

“…However, until now the beneficial effect of adding external electrical random noise to neural activity has mainly been studied via behavioural outcome measures in humans or via physiological single cell studies in animals (Onorato et al 2016;Remedios et al 2019). By contrast, it is largely unknown whether tRNS causes acute benefits when applied in-vivo to neural populations within the cortex.…”