english: In slow-wave deep sleep, our glial cells rinse cerebral spinal fluid throughout our brains, clearing away metabolic waste that accumulated in our synapses while we were awake.
non_english: In diepe slaap spoelen onze gliacellen ruggenmergvloeistof door ons brein, terwijl het afvalstoffen  in onze synaps opruimt wanneer we wakker zijn.