Effects of immobilization stress and of a benzodiazepine derivative on rat central dopamine system.

The effects of a novel benzodiazepine derivative, Ro 16-6028 on rat brain dopamine system were examined under stress and non-stress conditions. Thirty minutes restraint stress increased dopamine synthesis in two dopamine neuron regions, prefrontal cortex and nucleus accumbence. Ro 16-6028 inhibited potently dopamine synthesis in prefrontal cortex, nucleus accumbens and striatum in dose dependent manner under non-stress condition. Furthermore, Ro 16-6028 reverses the stress-induced augmentation of the synthesis in prefrontal cortex. These findings indicate that Ro 16-6028 has an anxiolytic profile and that central dopamine system plays an important role in stress reaction.