Table 1:

Effects of NMDA receptor ligands on delay discounting and probability discounting.

Delay Discounting
Drug	Doses	Mechanism of Action	Procedure	Delay Presentation	Delays	Effect onlmpulsve Choice	Citation
D-cyclo serine	3.25–30.0 mg/kg	Partial agonist at GluNl	Evenden and Ryan (1996)	Ascending	0–40 s	No effect	van den Berg et al. (2006)
D-cyclo serine	3.25–30.0 mg/kg	Partial agonist at GluNl	Evenden and Ryan (1996)	Ascending	0–100s	No effect	Yates. Gunkel, et al. (2017)
CSG 19755	2.5–20.0 mg/kg	C ompetitive antagora st at GluN2	Modifi ed Adj usting Delay	N/A	Titrated by subject	↑ impulsive choice (20.0 mgkg)a	Cottone et al. (2013)
CSG 19755	2.5–20.0 mg/kg	C ompetitive antagora st at GluN2	Evenden and Ryan (1996)	Ascending	0–100s	↑ impulsive choi c e ( 5.0 m g kg)	Yates. GunkeL et al. (2017)
Ketamine	2.5–20.0 mg/kg	Channel blocker	Modifi ed Adj usting Delay	N/A	Titrated by subject	↑ impulsive choice ( 10.0 & 20.0 mgkg)	Cottone et al. (2013)
Ketamine	5.0 mg/kg	Channel blocker	Evenden and Ryan (1996)	Ascending	0.4–6.5 s	↑ impulsive choice	Floresco et al. (2008)
Ketamine	2.5–10.0 mg/kg	Channel blocker	Evenden and Ryan (1996)	Ascending	0–50 s	↓ choiceforLL at 0-s delay( 10.0mgkg)	Yates et al. (2015)
Ketamine	2.5–10.0 mg/kg	Channel blocker	Evenden and Ryan (1996)	Ascending	0–100s	↓ choice forLL at 0-s delay( 10.0mgkg)	Yates. GunkeL et al. (2017)
Memantine	1.25–10.0 mg/kg	Channel blocker	Modifi ed Adj usting Delay	N/A	Titrated by subject	↑ impulsive choice (5.0 & 10.0 mgkg)	Cottone et al. (2013)
Memantine	2.5–10.0 mg/kg	Channel blocker	Evenden and Ryan (1996)	Ascending	0–100s	↓ choice for LL at 0-s delay(5.0 mgkg)	Yates. Gunkel, et al. (2017)
MK-S01	0.01–0.06 mg/kg	Channel blocker	Evenden and Ryan (1996)	Ascending	0–40 s	↓impulsivechoice(0.03 & 0.06mgkg)	Higgins et al. (2016)
MK-S01	0.01–0.3 mg/kg	Channel blocker	Evenden and Ryan (1996)	Ascending	0–50 s	↓impulsivechoice(0.03 mgkg)	Yates et al. (2015)
MK-S01	0.003–0.03 mg/kg	Channel blocker	Evenden and Ryan (1996)	Ascending	0–100s	No effect	Yates. GunkeL et al. (2017)
Ifenprodil	1.0–10.0 mg/kg	Noncompetitive antagonist at GluN2B	Evenden and Ryan (1996)	Ascending	0–100 s	↓ choice for LL at 0-s del ay ( 10.0 mgkg)	Yates. GunkeL et al. (2017)
CP-101.606	1.0 & 3.0 mg/kg	Noncompetitive antagonist at GluN2B	Evenden and Ryan (1996)	Ascending	0–40 s	No effect	Higgins et al. (2016)
Ro 63–190S	0.l-l.0 mg/kg	Noncompetitive antagonist at GluN2B	Evenden and Ryan (1996)	Ascending	0–40 s	↓ impulsive choice (1.0 mgkg)	Higgins et al. (2016)
Probability Discounting
Drug	Doses	Mechanism of Action	Procedure	OA Presentation	Odds Against	Effect on Risky Choice	Citation
Ketamine	2.5–10.0 mg/kg	Channel blocker	Cardinal & Howes (2005)	Ascending	0–15	↓ choice for LR at 0 OA(10.0 mgkg)	Yates et al. (2015)
Ketamine	2.5–10.0 mg/kg	Channel blocker	Cardinal & Howes (2005)	Ascending	0–31	No effect	Yates et al. (2016)
Ketamine	2.5–10.0 mg/kg	Channel blocker	Cardinal & Howes (2005)	Descending	0–31	↓ risky choice (10.0 mgkg)	Yates et al. (2016)
MK-S01	0.01–0.3 mg/kg	Channel blocker	Cardinal & Howes (2005)	Ascending	0–15	↑ risky choi ce (0.03 mgkg)	Yates et al. (2015)
MK-S01	0.01–0.3 mg/kg	Channel blocker	Cardinal & Howes (2005)	Ascending	0–31	↑ risky choice (0.03 mgkg)	Yates et al. (2016)
MK-S01	0.01–0.3 mg/kg	Channel blocker	Cardinal & Howes (2005)	Descending	0–31	↓ risky choice (10.0 mgkg)	Yates et al. (2016)
Ifenprodil	1.0–10.0 mg/kg	Noncompetitive antagonist at GluN2B	Cardinal & Howes (2005)	Ascending	0–31	No effect	Yates et al. (2016)
Ifenprodil	1.0–10.0 mg/kg	Noncompetitive antagonist at GluN2B	Cardinal & Howes (2005)	Descending	0–31	↓risky choice (10.0 mgkg)	Yates et al. (2016)

^aCaused an increase in response latencies; as such, Cottone et al. (2013) argued that CGS 19755 did not selectively alter impulsive choice.

Abbreviations: LL = larger later; LR = larger risky.