English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Absence seizures are characterized by bilaterally synchronous spike-and-wave discharges (SWDs) in the electroencephalogram, which reflect abnormal oscillations in corticothalamic networks. Although it was suggested that basal ganglia could modulate, via their feedback circuits to the cerebral cortex, the occurrence of SWDs, the cellular and network mechanisms underlying such a subcortical control of absence seizures remain unknown. The GABAergic projections from substantia nigra pars reticulata (SNR) to thalamocortical neurons of the ventral medial (VM) thalamic nucleus provide a potent network for the control of absence seizures by basal ganglia. The present in vivo study provides the first description of the activity of VM thalamic neurons during seizures in the genetic absence epilepsy rats from Strasbourg, a well established model of absence epilepsy. Cortical paroxysms were accompanied in VM thalamic neurons by rhythmic bursts of action potentials. Pharmacological blockade of excitatory inputs of nigrothalamic neurons led to a transient interruption of SWDs, correlated with a change in the activity of thalamic cells, which was increased in frequency and converted into a sustained arrhythmic firing pattern. Simultaneously, cortical neurons exhibited a decrease in their firing rate that was associated with an increase in membrane polarization and a decrease in input resistance. These new findings demonstrate that an inhibition of SNR neurons changes the activity of their thalamic targets, which in turn could affect cortical neurons excitability and, consequently, the generation of cortical epileptic discharges. Thus, the nigro-thalamo-cortical pathway may provide an on-line system control of absence seizures.

Activity of Ventral Medial Thalamic Neurons during Absence Seizures and Modulation of Cortical Paroxysms by the Nigrothalamic Pathway