Role of Laterodorsal Thalamic Nucleus during Absence Seizure Attacks

A typical absence epilepsy is a type of nonconvulsive and generalized epilepsy. The main feature of these attacks is a sudden brief impairment of consciousness. The disturbances in thalamocortical loop play an important role in pathogenesis of absence seizures. However, it is not clear that which part of this network triggers the seizure. This study was aimed to investigate the role of latrodorsal (LD) thalamic neurons during spike and wave discharges (SWDs) in WAG/Rij rats, as the most valid animal model of absence epilepsy.
Single unit activities in the LD thalamic nucleus and electrocorticogram of somatosensory cortex were simultaneously recorded in six-month-old WAG/Rij rats.
During SWDs, unit activity in the LD thalamic nucleus showed burst-like discharges, which were started before the peak component of SWDs. In SWD-free periods, burst like activity in the LD was reduced.
Our findings suggest that the burst firing of LD may stimulate the neocortex to exhibit SWDs. It can be concluded that inhibition of burst firing of LD neurons may reduce the frequency of SWDs.