Nonlinear influence of T-channels in an in silico relay neuron.
Thalamic relay cells express distinctive response modes based on the state of a low-threshold calcium channel (T-channel). When the channel is fully active (burst mode), the cell responds to inputs with a high-frequency burst of spikes; with the channel inactive ( tonic mode), the cell responds at a rate proportional to the input. Due to the T-channel's dynamics, we expect the cell's response to become more nonlinear as the channel becomes more active. To test this hypothesis, we study the response of an in silico relay cell to Poisson spike trains. We first validate our model cell by comparing its responses with in vitro responses. To characterize the model cell's nonlinearity, we calculate Poisson kernels, an approach akin to white noise analysis but using the randomness of Poisson input spikes instead of Gaussian white noise. We find that a relay cell with active T-channels requires at least a third-order system to achieve a characterization as good as a second-order system for a relay cell without T-channels.
Hynna
Kai M
KM
Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA. kai.hynna@gmail.com
Boahen
Kwabena A
KA
D000200:Action Potentials; D000465:Algorithms; D001185:Artificial Intelligence; D020747:Calcium Channels, T-Type / Q000502:physiology*; D003198:Computer Simulation; D003712:Dendrites / Q000502:physiology*; D008959:Models, Neurological; D017711:Nonlinear Dynamics; D016012:Poisson Distribution; D015203:Reproducibility of Results; D013788:Thalamus / Q000166:cytology
D020747:Calcium Channels, T-Type