Burst firing transitions in two-compartment pyramidal neuron induced by the perturbation of membrane capacitance

Neuronal membrane capacitance Cm is one of the prominent factors in action potential initiation and propagation and then influences the firing patterns of neurons. Exploring the roles that Cm plays in different firing patterns can facilitate the understanding of how different factors might influence neuronal firing behaviors. However, the impacts of variations in Cm on neuronal firing patterns have been only partly explored until now. In this study, the influence of Cm on burst firing behaviors of a two-compartment pyramidal neuron (including somatic compartment and dendritic compartment) was investigated by means of computer simulation, the value of Cm in each compartment was denoted as Cm,s and Cm,d, respectively. Two cases were considered, in the first case, we let Cm,s = Cm,d, and then changed them simultaneously. While in the second case, we assumed Cm,s ≠ Cm,d, and then changed them, respectively. From the simulation results obtained from these two cases, it was found that the variation of Cm in the somatic compartment and the dendritic compartment show much difference, simulated results obtained from the variation of Cm,d have much more similarities than that of Cm,s when comparing with the results obtained in the first case under which Cm,s = Cm,d. These different effects of Cm,s and Cm,d on neuronal firing behaviors may result from the different topology and functional roles of soma and dendrites. Numerical results demonstrated in this paper may give us some inspiration in understanding the possible roles of Cm in burst firing patterns, especially their transitions in compartmental neurons.