How does the thalamus help produce the slow waves and spindles of sleep? · Grey Matter

As arousal falls, the brainstem's neuromodulators withdraw and thalamic relay cells hyperpolarise, which switches them from faithful relaying to rhythmic bursts.

How does the thalamus help produce the slow waves and spindles of sleep?

As arousal falls, the brainstem's neuromodulators withdraw and thalamic relay cells hyperpolarise, which switches them from faithful relaying to rhythmic bursts. The thalamic reticular nucleus, inhibiting the relay cells in rhythm, generates the sleep spindles (bursts of about 11 to 15 Hz), and the loops between thalamus and cortex, together with the cortex's own slow oscillation, produce the large slow waves of deep sleep. In this mode the thalamus transmits little from the senses, which is part of why the sleeping brain is cut off from the world.