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.
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.
Authors: Tatyana Kanyshkova; Patrick Meuth; Pawan Bista; Zhiqiang Liu; Petra Ehling; Luigi Caputi; Michael Doengi; Dane M Chetkovich; Hans-Christian Pape; Thomas Budde Journal: Neurobiol Dis Date: 2011-09-16 Impact factor: 5.996
Authors: Konstantin Wemhöner; Tatyana Kanyshkova; Nicole Silbernagel; Juncal Fernandez-Orth; Stefan Bittner; Aytug K Kiper; Susanne Rinné; Michael F Netter; Sven G Meuth; Thomas Budde; Niels Decher Journal: Front Mol Neurosci Date: 2015-11-03 Impact factor: 5.639