Effects of beta-carbolines in animal models of anxiety.

Animal models of anxiety can be classified into three main groups: those based on conflict or conditioned fear; those exploiting the anxiety produced by novelty; those in which anxiety or aversion is chemically induced. This review briefly describes the existing tests and, where available, the results obtained with beta-carbolines. Many of the beta-carbolines are anxiogenic in the tests, however ZK 91296 and ZK 93423 appear to have anxiolytic properties, and ZK 93426 has a similar profile to that of the benzodiazepine receptor antagonist RO 15-1788. By the results across the spectrum of tests, the reliability and sensitivity of the tests is assessed. The evidence that the anxiogenic and anxiolytic actions of the beta-carbolines are mediated by the BDZ binding sites is also discussed.