Table 4.

Receptor mechanisms underlying Δ⁹-THC-induced learning and memory impairments.

Assay	Target	Antagonist	Knockout mouse	Results	References
Spatial learning and memory
RAM	CB1R	SR141716A	N/A	Blocked	Lichtman and Martin (1996)
MWM	CB1R	SR141716A	CB1-KO	Blocked	Varvel and Lichtman (2002)
MWM	Cell-type specific CB1Rs	N/A	GABA-CB1-KO Glu-CB1-KO GFAP-CB1-KO	No effect No effect Blocked	Han et al. (2012)
MWM	NDMARs	AP-5	N/A	Blocked	Han et al. (2012)
MWM	COX-2	NS-398	COX-2-KO−	Blocked	Chen et al. (2013)
MWM	A1R	Caffeine	N/A	Enhanced	Sousa et al. (2011)
RAM	5-HT	Clomipramine 5-MeODMT	N/A	Attenuated Attenuated	Egashira et al. (2002)
RAM	5-HT2	DOI	N/A	Attenuated	Egashira et al. (2002)
RAM	5-HT1A	8-OHDPAT	N/A	Reversed	Inui et al. (2004)
RAM	AchE	Physostigmine Tetrahydroaminoacridine	N/A	Attenuated Attenuated	Mishima, Egashira, Matsumoto, Iwasaki, and Fujiwara (2002)
Short-term memory
DNMS	CB1R	SR141617A	N/A	Blocked	Hampson and Deadwyler (2000)
DNMP	CB1R	SR141617A	N/A	Attenuated	Hampson and Deadwyler (2000) and Mallet and Beninger (1998a, b)
NOR	Mitochondria-specific CB1R	N/A	DN22-CB1	Blocked	Hebert-Chatelain et al. (2016)
NOR	PKC	NPC CHE	N/A	Blocked Blocked	Busquets-Garcia et al. (2018)
DNMP	A1R	Caffeine CPT	N/A	Enhanced Enhanced	Panlilio et al. (2012)
NOR	A2AR	SCH442416 KW-6002	N/A	Attenuated No effect	Aso et al. (2019)
NOR	5-HT2AR	MDL 100907	N/A	Reversed	Viñals et al. (2015)
NOR	5-HT2AR	N/A	5-HT2AR-K0	Attenuated	Viñals et al. (2015)
DNMS	ACHe	Rivastigmine	N/A	Blocked	Goonawardena, Robinson, Hampson, and Riedel (2010)

Abbreviations: RAM—radial arm maze, MWM—Morris water maze, DNMS—delayed nonmatch to sample, DNMP—delayed nonmatch to position, NOR—novel object recognition.