▁is ▁expressed ▁mostly ▁in ▁neur ons ▁and ▁test is , ▁although ▁expression ▁in ▁most ▁other ▁t issues ▁has ▁also ▁been ▁shown ▁at ▁lower ▁levels . ▁ ▁GL UT 8 ▁is ▁expressed ▁at ▁moder ate ▁levels ▁in ▁the ▁brain , ▁most ▁strik ingly ▁in ▁hi pp oc amp us . ▁Whether ▁the ▁gl uc ose ▁trans porter ▁plays ▁any ▁role ▁in ▁these ▁cells ▁remains ▁to ▁be ▁shown . ▁ ▁Sub cell ular ▁local ization ▁▁ ▁Con tr ary ▁to ▁GL UT 4 , ▁GL UT 8 ▁( pre viously ▁known ▁as ▁GL UT X 1 ) ▁is ▁not ▁ins ul in - sens itive . ▁In ▁other ▁words , ▁ins ul in ▁does ▁not ▁promote ▁GL UT 8 ▁trans location ▁to ▁the ▁cell ▁surface ▁in ▁neur ons ▁as ▁well ▁as ▁in ▁trans fect ed ▁cell ▁lines . ▁ ▁Where ▁in ▁the ▁cell ▁GL UT 8 ▁is ▁local ized ▁in ▁not ▁yet ▁clear . ▁Most ▁GL UT 8 ▁is ▁not ▁present ▁at ▁the ▁cell ▁surface . ▁Some ▁co - local ization ▁with ▁both ▁the ▁end op las mic ▁ret icul um ▁and ▁late ▁end os om es / ly s os om es ▁has ▁been ▁published . ▁ ▁When ▁the ▁N - term inal ▁di - le uc ine ▁mot if ▁is ▁mut ated ▁into ▁a ▁di - al an ine ▁mot if , ▁GL UT 8 ▁is ▁located ▁mostly ▁at ▁the ▁cell ▁surface ▁in ▁X en opus ▁o ocy tes ▁and ▁m amm al ian ▁cells ▁such ▁as ▁HE K ▁ 2 9 3