TABLE 3

Summary of hot plate antinociceptive responses in mice lacking β-arrestin1 or β-arrestin2 in response to different opioid agonists

	Morphine	Methadone	Fentanyl	Etorphine	Oxycodone	Heroin
Hot plate antinociception
βarr1-KO	=^{^a}	N.D.	N.D.	N.D.	N.D.	N.D.
βarr2-KO	↑^{^a,,–^d}	=^{^a,^d}	=^{^a,^d}	=^{^a}	=^{^d}	↑^{^a}
Hot plate antinociceptive tolerance
βarr2-KO	↓^{^b,^d}	=^{^d}	=^{^d}	N.D.	=^{^d}	N.D.

=, equivalent to wild type (WT) response at 10 mg/kg s.c.; ↑, significant increase in response; ↓, significant decrease in response; N.D., not determined.
↵a Bohn et al., 2004.
↵b Bohn et al., 1999.
↵c Bohn et al., 2000.
↵d Raehal and Bohn, 2011.