title: 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.
authors.affiliation: Institute Pasteur-Cenci Bolognetti Foundation, Dept. Physiology and Pharmacology, Sapienza University, Rome, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Onorato
authors.affiliation: Institute Pasteur-Cenci Bolognetti Foundation, Dept. Physiology and Pharmacology, Sapienza University, Rome, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: D'Alessandro
authors.affiliation: Institute Pasteur-Cenci Bolognetti Foundation, Dept. Physiology and Pharmacology, Sapienza University, Rome, Italy.
authors.forename: Maria Amalia
authors.initials: MA
authors.lastname: Di Castro
authors.affiliation: Institute Pasteur-Cenci Bolognetti Foundation, Dept. Physiology and Pharmacology, Sapienza University, Rome, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Renzi
authors.affiliation: Institute Pasteur-Cenci Bolognetti Foundation, DAHFMO-Unit of Histology and Medical Embryology, IIM, Sapienza University of Rome, Rome, Italy.|Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Rome, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Dobrowolny
authors.affiliation: Institute Pasteur-Cenci Bolognetti Foundation, DAHFMO-Unit of Histology and Medical Embryology, IIM, Sapienza University of Rome, Rome, Italy.|Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Musarò
authors.affiliation: Dept. of Neurosciences, Mental Health and Sensory Organs, Sapienza University, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Salvetti
authors.affiliation: Institute Pasteur-Cenci Bolognetti Foundation, Dept. Physiology and Pharmacology, Sapienza University, Rome, Italy.|NeuroMed, Pozzilli, (IS), Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Limatola
authors.affiliation: Dept of Physics, Sapienza University, Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Crisanti
authors.affiliation: Institute Pasteur-Cenci Bolognetti Foundation, Dept. Physiology and Pharmacology, Sapienza University, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Grassi
mesh_terms: D000200:Action Potentials; D000818:Animals; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D009622:Noise; D011984:Sensory Receptor Cells / Q000166:cytology*; D013269:Stochastic Processes