1 - A ▁disc rimin ates ▁more ▁effectively ▁than ▁any ▁other ▁known ▁lig and ▁between ▁the ▁NR 2 B ▁and ▁NR 2 C ▁sub un its ▁of ▁N MD AR . ▁ ▁Con ant ok in - Br ▁or ▁- S 1 ▁ ▁Con - Br ▁( or ▁Con - S 1 , ▁) ▁is ▁isolated ▁from ▁Con us ▁bre tt ingham i ▁( now ▁Con us ▁sul c atus ), ▁and ▁is ▁the ▁only ▁known ▁con ant ok in ▁with ▁a ▁high ▁select ivity ▁for ▁the ▁NR 2 D ▁sub unit ▁of ▁N MD AR . ▁ ▁Syn th etic ▁derivatives ▁ ▁Con - G - based ▁ ▁Con - G [ γ 7 A ] ▁Con - G [ γ 7 K ] ▁and ▁Con - G [ S 1 6 Y ] ▁are ▁synth etic ▁Con - G ▁pe pt ides , ▁where ▁the ▁Gla ▁resid ue ▁at ▁position ▁ 7 ▁is ▁replaced ▁with ▁an ▁al an ine ▁or ▁a ▁l ys ine ▁resid ue , ▁or ▁the ▁ser ine ▁at ▁position ▁ 1 6 ▁is ▁replaced ▁with ▁a ▁ty ros ine ▁resid ue , ▁respectively . ▁Con - G [ γ 7 A ] ▁is ▁four fold ▁more ▁pot ent ▁than ▁the ▁native ▁pe pt ide , ▁Con - G , ▁while ▁Con - G [ γ 7 K ] ▁is ▁as ▁pot ent ▁as ▁Con - G . ▁The ▁first ▁two ▁pe pt ides ▁appear ▁to ▁distinguish ▁N MD AR ▁sub types ▁in ▁mid - front al ▁gy