Combining alprazolam with systematic desensitization therapy for dental injection phobia.

To determine whether a benzodiazepine facilitates systematic desensitization, 144 subjects with dental injection phobia received systematic desensitization in combination with placebo or one of two doses of alprazolam (0.5mg or 0.75mg).

Nitrous oxide analgesia in humans: acute and chronic tolerance.

Electrical tooth stimulation was used to investigate whether humans develop tolerance to nitrous oxide (N(2)O) analgesia within a single administration as well as over repeated administrations. In a double-blind cross-over experiment, 77 subjects received a 40-min administration of 38% N(2)O at one session and placebo gas at the other. The sessions were separated by 1 week and the order of gas administration was counterbalanced.

Conditioned place aversion and self-administration of nitrous oxide in rats.

The rewarding/aversive effects of nitrous oxide (N(2)O) were evaluated using the place conditioning paradigm. Male Long-Evans rats (N=103) received a daily 40-min gas exposure for 8 consecutive days that alternated between two distinct chambers. A control group received placebo gas in both chamber types, while the N(2)O groups (8%, 15%, 30%, and 60% N(2)O) received four consistent pairings of N(2)O with one chamber type and four pairings of placebo gas with the other.