Erasing Synapses in Sleep: Is It Time to Be SHY?

Table 1

Scaling factors and the sleep-wake cycle.

	Wake	Sleep	Promotes
BDNF	↑↑	↓↓	Synaptic downscaling [7, 30–33]
Arc	↑↑	↓↓	Synaptic downscaling [30, 31, 34–37]
Homer1A	↑↑	↓↓	Synaptic downscaling [34, 37]
Tnfα	↓↓	↑↑	Synaptic upscaling [38–40]
Retinoic acid	??	??	Synaptic upscaling* [41, 42]

The expression of scaling factors is inconsistent with net downscaling during sleep.
*Retinoic acid is linked to SWA generation, but sleep/wake expression patterns are unknown.