Table 2. Direct Comparison between Inhibition Constant (K_i) and IC₅₀ Values for 3b and 3e.

	3b				3e
	[3H]naloxone		[3H]DAMGO		[3H]naloxone		[3H]DAMGO
region	IC50/nM	Ki/nM	IC50/nM	Ki/nM	IC50/nM	Ki/nM	IC50/nM	Ki/nM
thalamus	831	86	1455	79	485	50	888	48
striatum	887	84	1238	62	250	24	812	40
presubiculum	1080	137	1890	128	286	37	829	58