TEMPERATURE EFFECTS ON THE PROPAGATION SPEED OF ACTION POTENTIALS

In neurons, passive membrane current flows have an important functional role in electrical signaling in nerve cells, including action potential propagation. Therefore, it becomes relevant to have a quantitative understanding of how passive current flows evolve as the action potential travels along the axon. Of particular interest in this study is the effect that temperature has on this mechanism, possibly of crucial relevance for the survival of the animal. In this study we use computer simulations to test the effect of temperature changes on the propagation speed of action potentials along the axon of a neuron. We employ a compartmental model for the axon where each compartment is connected to its two nearest neighbors via a reciprocal electrical coupling. The strength of the coupling is related to conductances which are considered as parameters in the model equations. The strong the coupling (higher conductance values) the easier for the signal to travel on the axon. Physiological features such as diameter and resistivity of the compartment are shown to play important roles in the way the units communicate with one another. Additionally, we show experimental results exhibiting qualitative agreement with our computational output