Berlin 2024 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

BP: Fachverband Biologische Physik

BP 1: Systems and Network Biophysics

BP 1.9: Talk

Monday, March 18, 2024, 12:15–12:30, H 0112

A stochastic conductance-based model of the hawkmoth Manduca sexta olfactory receptor neuron — •Mauro Ariel Forlino, Aditi Vijayan, Katrin Schröder, Anna Schneider, Monika Stengl, and Martín García — Kassel University, Kassel, Germany

The long trichoid sensillum in male hawkmoths, Manduca sexta, is innervated by two olfactory receptor neurons (ORNs) that respond to the pheromone released by female moths to attract conspecific mates. In the absence of odor stimuli, pheromone-sensitive ORNs in hawkmoths exhibit non-randomly distributed spontaneous spikes. Analyzing spike distribution is crucial for identifying different mechanisms at play. The random opening and closing of ion channels introduce internal fluctuations in neurons, known as channel noise, which contributes to the variability in spike distribution and determines whether a single spike or a burst occurs. Furthermore, insect ORNs serve as endogenous peripheral circadian clock neurons, leading to the expression of daytime-dependent rhythmic spike distributions. In this study, we present a novel conductance-based model that incorporates the olfactory receptor coreceptor (ORCO) as a pacemaker ion channel with linear conductance dependent on cAMP concentration. Our model takes into account that cAMP express daytime-dependent rhythms with concentration being maximal during activity phase. By utilizing stochastic differential equations based on the microscopic Markovian states of ion channels, our model can reproduce the observed spike distribution with its circadian oscillations.

Keywords: Conductance-based model; Stochastic; Markov chain; Olfaction; Chronobiology