Analysis of the role of the low threshold currents IT and Ih in intrinsic delta oscillations of thalamocortical neuron.

G. MATO; M. NADAL; Y. AMARILLO

Frontiers in Computational Neuroscience

Frontiers

Lugar: Lausanne; Año: 2015 vol. 9 p. 1 - 9

Thalamocortical neurons are involved in the generation and maintenance of brain rhythms associated with global functional states. The repetitive burst firing of TC neurons at deltafrequencies (1?4 Hz) has been linked to the oscillations recorded during deep sleep and during episodes of absence seizures. To get insight into the biophysical properties that are the basis for intrinsic delta oscillations in these neurons, we performed a bifurcationanalysis of a minimal conductance-based thalamocortical neuron model including only the IT channel and the sodium and potassium leak channels. This analysis unveils the dynamics of repetitive burst firing of TC neurons, and describes how the interplaybetween the amplifying variable mT and the recovering variable hT of the calcium channeIT is sufficient to generate low threshold oscillations in the delta band. We also exploredthe role of the hyperpolarization activated cationic current Ih in this reduced model and determine that, albeit not required, Ih amplifies and stabilizes the oscillation.