Biochemistry Questions / Explain the use of animal models in studying anxiety and how behavioural experiments can elicit fear responses.

Animal models can play an important role in studying anxiety and the effects drugs can have on it.

The elevated cross maze consists of a narrow platform, with two arms of the cross protected on the sides, and the other two exposed. An anxiety response is seen in a rodent when it leaves the protected sections and enters the unprotected, exposed arms. A good anxiolytic drug causes the rodent to spend more time on the exposed sections, demonstrating the suppression of the anxiety response.

Another animal model that is used to study the anxiety response in rodents is the light-dark box. This consists of a chamber with one half under bright illumination, and the other in the dark. A rodent will prefer the dark side under normal conditions, however on the administration of a benzodiazepine, it will be happy to go on either side of the chamber. This model only works with benzodiazepines, though, and so isn’t representative with other classes of drugs.

Both of these animal models can elicit fear responses, which are then suppressed by the anxiolytic. This allows the study of the drugs, determining their efficacy at suppressing anxiety responses.