Upon strong and prolonged excitation, neurons can undergo a silent state called depolarization block that is often associated with disorders such as epileptic seizures. Here we show that neurons in the peripheral olfactory system undergo depolarization block as part of their normal physiological function. Typically, olfactory sensory neurons enter depolarization block at odor concentrations three orders of magnitude above their detection threshold, thereby defining receptive fields over concentration bands. The silencing of high-affinity olfactory sensory neurons produces sparser peripheral odor representations at high-odor concentrations, which might facilitate perceptual discrimination. Using a conductance-based model of the olfactory transduction cascade paired with spike generation, we provide numerical and experimental evidence that depolarization block arises from the slow inactivation of sodium channels — a process that could affect a variety of sensory neurons. The existence of ethologically-relevant depolarization block in olfactory sensory neurons creates a new dimension that expands the peripheral encoding of odors.

For details on the methodology for data collection and data processing please see the publication titled: "Depolarization block of olfactory sensory neurons adds a new dimension to odor encoding".

Please see the folder custom_code.zip for all scripts utlizing the data presented here. Other code can be found in the file: hdbscan_spike_sorter.zip which contains code to conduct spike sorting and in the file: OB1_GUI.zip which contains code to control the Elveflow OB1 microfluidics device used to collect the electrophysiology data presented here. Any updates will be provided here: https://gitlab.com/davidtadres/ob1_gui, https://gitlab.com/davidtadres/hdbscan_spike_sorter/, https://gitlab.com/LouisLab/depolarization_block_publication