Cell-intrinsic mechanisms of temperature compensation in a grasshopper sensory receptor neuron.
Bottom Line: The nervous systems of poikilothermic animals must have evolved mechanisms enabling them to retain their functionality under varying temperatures.Auditory receptor neurons of grasshoppers respond to sound in a surprisingly temperature-compensated manner: firing rates depend moderately on temperature, with average Q10 values around 1.5.Remarkably, this type of temperature compensation need not come at an additional metabolic cost of spike generation.
Affiliation: Institute of Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany.Show MeSH
Related in: MedlinePlus
Mentions: The impacts of conductance parameters on f-I curve temperature dependence and energy consumption were not significantly correlated in this case (ρ = −0.23, p=0.56). In particular, the key parameters of largest influence on these features belonged to different channel groups: potassium channels in case of temperature compensation and sodium channels in case of energy efficiency of spike generation. We verified that the large influence of sodium channels was not biased by our sodium-current-based definition of metabolic cost. Three alternative measures—two quantifying energy efficiency based on the separability of sodium and potassium currents (Alle et al., 2009), the other defined by the total potassium current—all confirmed the temperature dependence of sodium channel inactivation as the most influential parameter for spiking cost (Figure 3—figure supplement 1).
Affiliation: Institute of Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany.