- medi ated ▁sp ont aneous ▁E PS C s ▁( s E PS C s ) ▁and ▁N MD A - g ated ▁curr ents ▁in ▁cort ical ▁neur ons ▁might ▁be ▁a ▁result ▁of ▁actions ▁on ▁both ▁di h eter omer ic ▁( NR 1 / NR 2 B ) ▁and ▁tri h eter omer ic ▁( NR 1 / NR 2 A / NR 2 B ) ▁N MD AR . ▁ ▁Mode ▁of ▁action ▁ ▁Con - G ▁does ▁not ▁act ▁directly ▁at ▁the ▁g ly c ine ▁binding ▁site . ▁It ▁can ▁at ten uate ▁both ▁the ▁amplitude ▁and ▁the ▁decay ▁time ▁constant ▁of ▁N MD A - medi ated ▁E PS C s ▁and ▁significantly ▁and ▁revers ibly ▁affect ▁other ▁different ▁properties ▁of ▁N MD AR - medi ated ▁s E PS C s ▁in ▁cult ured ▁neur ons . ▁The ▁effect ▁of ▁Con - G ▁on ▁the ▁frequency ▁of ▁the ▁s E PS C s ▁most ▁likely ▁rel ates ▁to ▁ant agon izing ▁the ▁N MD AR . ▁ ▁Target ▁ ▁Con ant ok ins ▁target ▁N MD AR . ▁Each ▁sub type ▁select ively ▁targets ▁different ▁sub un its ▁of ▁the ▁re ceptor . ▁ ▁To x icity ▁ ▁Some ▁of ▁these ▁pe pt ide ▁effects ▁are ▁age - dependent , ▁such ▁as ▁the ▁induction ▁of ▁sleep - like ▁state ▁in ▁young ▁m ice ▁and ▁hyper active ▁behavior ▁in ▁older ▁m ice . ▁ ▁In trat he cal ▁administration ▁of ▁dos es ▁greater ▁than ▁