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Updated: Jun 6, 2026
Recording and Modulation of Epileptiform Activity in Rodent Brain Slices Coupled to Microelectrode Arrays
Published on: May 15, 2018
Spike-wave discharges in WAG/Rij rats are preceded by delta and theta precursor activity in cortex and thalamus
Gilles van Luijtelaar1, Alexander Hramov, Evgenia Sitnikova
1Donders Center for Cognition, Radboud University Nijmegen, Nijmegen, The Netherlands. g.vanluijtelaar@donders.ru.nl
Objective:
In order to unravel the mechanisms underlying the "sudden" onset of spontaneous absences in genetically prone subjects, we investigated the immediate precursors of spike-wave discharges (SWDs) produced in cortico-thalamo-cortical neuronal networks.
Methods:
A time-frequency analysis of the cortical and thalamic ECoG of WAG/Rij rats was accomplished with a continuous wavelet decomposition of SWDs, 3 s prior to the onset of SWDs (pre-SWD), and in control periods devoid of SWDs.
Results:
The pre-SWD ECoG consisted of delta and theta components in 80-90% of all SWDs simultaneously in cortex and thalamus, the co-occurrence of delta and theta was rare (7%) during control periods. The occurrence of delta and theta events in pre-SWDs in the cortex preceded that in the thalamus. The frequency of theta component in cortex correlated positively with that in thalamus, this correlation was less strong for delta.
Conclusion:
Precursors of SWDs comprise of delta and theta, their co-occurrence is typical for non-epileptic periods. Thalamic and cortical theta are strongly related. Rhythmic precursors appear earlier in cortex than in thalamus, and this is in line with the cortical origin of SWD.
Significance:
Simultaneous presence of delta and theta events in EEG is a condition for the occurrence of SWDs.
