Thigmotaxis as a test for anxiolytic activity in rats

Area of Science:

• Neuroscience
• Behavioral Pharmacology

Background:

• Phylogenetically prepared fear reactions are proposed as behavioral assays for anxiolytic agents.
• Thigmotaxis in rodents is a natural behavior that can be modified by anxiolytic drugs.

Purpose of the Study:

• To evaluate thigmotaxis as a behavioral assay for anxiolytic activity.
• To assess the drug-class specificity of the anxiolytic effects on thigmotaxis.

Main Methods:

• Rats were administered anxiolytic agents (diazepam, chlordiazepoxide, pentobarbital) and their thigmotactic behavior was measured.
• Analysis of covariance was used to control for general activity effects.
• Non-anxiolytic drugs (d-amphetamine, morphine, chlorpromazine) were also tested.

Main Results:

• Anxiolytic agents dose-dependently suppressed thigmotaxis, with relative potencies mirroring human anxiolytic treatment.
• After controlling for general activity, the anti-thigmotaxic effect demonstrated drug-class specificity.
• d-amphetamine, morphine, and chlorpromazine did not produce anti-thigmotaxic effects.

Conclusions:

• Thigmotaxis suppression by anxiolytic agents suggests its utility as a behavioral assay for anxiolytic activity.
• The test exhibits a degree of specificity for anxiolytic drugs, supporting its validity.
• This study reinforces previous findings on the usefulness of thigmotaxis as an anxiolytic test in rats.