TY - JOUR
T1 - Multiple dynamical modes of thalamic relay neurons
T2 - Rhythmic bursting and intermittent phase-locking
AU - Wang, X. J.
N1 - Funding Information:
Acknowledgemenrs-It is a pleasure to thankL . P. Kadanoff for his suouort. and J. Rinzel. N. Koaell and M. Rush for discussion; This work is partly supported by the Office of Naval Research under contract No. NOOOl4-905-1194.
PY - 1994/3
Y1 - 1994/3
N2 - A model of thalamocortical relay neuron is studied to assess whether a 7-14 Hz (spindle) oscillation and a 0.5-4 Hz (delta) oscillation may result from the interplay between a T-type calcium current and a non-specific cation sag current. With moderate change of membrane parameter values, the model neuron can exhibit both the spindle and delta rhythms, at different levels of hyperpolarization; only the slower (delta) one or none. In the case when the model neuron is not intrinsically oscillatory, its response to rhythmic hyperpolarization is complex, and displays the "intermittent phase-locking" phenomenon where bursts of Na+ action potentials occur infrequently but their occurrence is phase-locked to the rhythmic input. The rhythmic bursting, whenever possible, is shown to emerge (bifurcate) from a subthreshold oscillation. Near the bifurcation chaotic discharge patterns are observed, where spikes occur intermittently at randomly chosen cycles of a mostly subthreshold slow oscillation. Furthermore, when both the spindle and delta modes can be realized, the transition between the two appears as a sudden drop of the rhythmic frequency with increased hyperpolarization. The T-type calcium current and the sag current may explain the "intermittent phase-locking" phenomenon that is characteristic to thalamic relay neurons during spindle oscillation and provide a cellular basis for the 7-14 Hz rhythm and the slower 0.5-4 Hz rhythm.
AB - A model of thalamocortical relay neuron is studied to assess whether a 7-14 Hz (spindle) oscillation and a 0.5-4 Hz (delta) oscillation may result from the interplay between a T-type calcium current and a non-specific cation sag current. With moderate change of membrane parameter values, the model neuron can exhibit both the spindle and delta rhythms, at different levels of hyperpolarization; only the slower (delta) one or none. In the case when the model neuron is not intrinsically oscillatory, its response to rhythmic hyperpolarization is complex, and displays the "intermittent phase-locking" phenomenon where bursts of Na+ action potentials occur infrequently but their occurrence is phase-locked to the rhythmic input. The rhythmic bursting, whenever possible, is shown to emerge (bifurcate) from a subthreshold oscillation. Near the bifurcation chaotic discharge patterns are observed, where spikes occur intermittently at randomly chosen cycles of a mostly subthreshold slow oscillation. Furthermore, when both the spindle and delta modes can be realized, the transition between the two appears as a sudden drop of the rhythmic frequency with increased hyperpolarization. The T-type calcium current and the sag current may explain the "intermittent phase-locking" phenomenon that is characteristic to thalamic relay neurons during spindle oscillation and provide a cellular basis for the 7-14 Hz rhythm and the slower 0.5-4 Hz rhythm.
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U2 - 10.1016/0306-4522(94)90095-7
DO - 10.1016/0306-4522(94)90095-7
M3 - Article
C2 - 8190268
AN - SCOPUS:0028218933
SN - 0306-4522
VL - 59
SP - 21
EP - 31
JO - Neuroscience
JF - Neuroscience
IS - 1
ER -