Fig. 2.
Dose-dependent sedative behaviors differentially induced following intravenous injections of zolpidem and experimental compounds with subtype selectivity. Zolpidem has preferential affinity for α1 subunit-containing GABAA receptors, whereas the three compounds have the following profiles: HZ-166 (selective efficacy for α2 and α3 subunit-containing GABAA receptors, relatively high efficacy as allosteric modulator), MRK-696 (nonselective partial allosteric modulator), TPA-023B (selective efficacy for α2, α3, and α5 subunit-containing GABAA receptors, partial allosteric modulator). All other details as in Fig. 1. Note the absence of moderate sedation data—these ligands did not induce significant changes in this observable behavior. *P ≤ 0.05, vs. vehicle (V), Bonferroni t tests, n = 4.