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Bazhenov,
Maxim HHMI,
The Salk Institute, CNL Patterns of spiking--bursting activity in the thalamic reticular nucleus initiate sequences of spindle oscillations in intact thalamic network Recent intracellular and local field potential recordings from reticular thalamic (RE) neurons in vivo as well as a computational modeling of the isolated RE nucleus suggest that at the relatively hyperpolarized levels of membrane potentials the inhibitory postsynaptic potentials (IPSPs) between RE cells can be reversed and the GABAa mediated depolarization can underly the spatio--temporal patterns persisting in the RE nucleus. The role of this activity for the spatio-temporal properties of spindle oscillations was investigated in the computer models of RE and thalamocortical (TC) cells. In a one-dimensional network of RE and TC cells, sequences of spindle oscillations were followed by the localized patterns of spike-burst activity propagating inside the RE network and triggering new sequences of spindle oscillations. The length of the interspindle lulls depended on the intrinsic and synaptic properties of RE and TC cells and was in the range of 3-20 sec. In a two-dimensional model, GABAa mediated 2-3 Hz oscillations persisted in the RE nucleus during interspindle lulls and simultaneously initiated spindle sequences in the many foci of the RE-TC network. Our model predicts that the intrinsic properties of the reticular thalamus may contribute to the synchrony of spindle oscillations in vivo.
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