Corticothalamic feedback can induce hypersynchronous low-frequency rhythms
in the physiologically intact thalamus
Damien Debay, Alain Destexhe and Thierry Bal
Neurocomputing 38: 529-538, 2001.
Thalamic circuits are capable of generating oscillations of different
frequency and level of synchrony. However, it is not known how these
oscillation types are controlled in the intact brain. Here we consider the
influence of corticothalamic feedback onto the thalamus by using thalamic
slices and computational models. Models predicted that strong activation of
corticothalamic feedback should transform the normal spindle oscillations
(6-10 Hz) into hypersynchronous slow (2-4 Hz) oscillations. By implementing
this feedback paradigm in ferret thalamic slices, we could observe this
transformation. Thalamic reticular neurons show a dramatic increase of
firing, but not interneurons, suggesting that this effect is mediated mostly
through the reticular nucleus. We conclude that cortical inputs can induce
slow hypersynchronous oscillations in the physiologically intact thalamus,
which has clear implications for understanding the genesis of pathologies such
as absence seizures, and more generally the downstream control of thalamic
nuclei by the cerebral cortex.
See also the following related article:
Bal T, Debay D and Destexhe A. Cortical feedback
controls the frequency and synchrony of oscillations in the visual thalamus.
Journal of Neuroscience 20: 7478-7488, 2000.
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