Electrical activity of the posterior thalamic nucleus and the hippocampus during wakefulness and desynchronized sleep in the rat: a spectral analysis

The electrical activity of the posterior thalamic nuclear complex was studied in rats and related to the simultaneous hippocampal electro-oscillogram. Electrocorticographic tracings and spectral analysis showed that during attentive wakefulness the electro-oscillogram peaked at 8 Hz and in desynchronized sleep it oscillated at regular frequencies between 8 and 9 Hz. In quiet wakefulness, frequency was lower (around 5 Hz) and during synchronized sleep rhytmicity disppeared. The electrophysiological patterns during wakefulness and desynchronized sleep are proposed to be linked to the retrieeval and combination of information for the generation of attention and dream content