ic ▁in hib ition ▁by ▁G AB A . ▁ ▁Less ▁well ▁character ized ▁effects ▁of ▁bar bit ur ates ▁include ▁direct ▁in hib ition ▁of ▁A MP A - type ▁gl ut am ate ▁re cept ors , ▁suppress ing ▁exc itat ory ▁gl ut am ater g ic ▁ne uro trans mission . ▁ ▁References ▁ ▁External ▁links ▁▁▁ ▁Category : Bar bit ur ates <0x0A> </s> ▁App enz ell ▁Rail ways ▁( , ▁AB ) ▁is ▁a ▁Swiss ▁railway ▁company ▁with ▁headquarters ▁in ▁Her is au . ▁It ▁oper ates ▁a ▁network ▁of ▁rail ways ▁in ▁the ▁cant ons ▁of ▁App enz ell ▁Inner rh oden , ▁App enz ell ▁Aus ser rh oden ▁and ▁St . ▁G allen . ▁ ▁History ▁ ▁The ▁orig ins ▁of ▁the ▁App enz eller ▁Bah nen ▁company ▁lies ▁in ▁a ▁number ▁of ▁formerly ▁independent ▁companies ▁and ▁railway ▁lines : ▁▁ ▁The ▁R or sch ach – He iden - B erg bahn ▁( R H B ), ▁which ▁opened ▁its ▁line ▁from ▁R or sch ach ▁to ▁He iden ▁in ▁ 1 8 7 5 . ▁ ▁The ▁App enz eller bahn ▁( AB ), ▁which ▁opened ▁its ▁line ▁from ▁W ink eln ▁to ▁Ur n ä sch ▁via ▁Her is au ▁in ▁ 1 8 7 5 , ▁with ▁an ▁extension ▁from ▁Ur n ä sch ▁to ▁App enz ell ▁in ▁ 1 8 8 6 . ▁In ▁ 1 9 1 3 , ▁the ▁line ▁from ▁Her is au ▁to ▁W