Corticothalamic 5–9 Hz oscillations are more pro‐epileptogenic than sleep spindles in rats (original) (raw)

2006, The Journal of Physiology

Absence‐related spike‐and‐wave discharges (SWDs) occur in the thalamocortical system during quiet wakefulness or drowsiness. In feline generalized penicillin epilepsy, SWDs develop from sleep spindles. In contrast, in genetic absence epilepsy rats from Strasbourg (GAERS), SWDs develop from wake‐related 5–9 Hz oscillations, which are distinct from spindle oscillations (7–15 Hz). Since these two oscillation types share common frequency bands and may contribute to SWD genesis, it is important to compare their thalamic cellular mechanisms. Under neuroleptic analgesia, in GAERS and control non‐epileptic rats barbiturates abolished both SWDs and 5–9 Hz oscillations but increased the incidence of spindle‐like oscillations. Within the thalamocortical circuit 5–9 Hz oscillations occurred more coherently than spindle‐like oscillations. Intracellular events associated with 5–9 Hz and spindle‐like oscillations were distinctively different in both thalamic relay and reticular neurons. In both ce...