Journal of Clinical & Experimental Pharmacology

Abstract

Ethological Characterization and Pharmacological Validation of Elevated “I–maze” as Animal Model of Anxiety

Ritu Gilhotra and Neeraj Gilhotra

Abstract Objective: The objective of the present study was to design a novel animal maze which can detect anxiety in mice and effect of different anxiogenic and anxiolytic treatments. Methods: The maze was behaviorally validated by recording the behaviors of mice on the maze before and after administration of anxiolytic drug treatments like Diazepam (1 and 2 mg/kg), Gabapentin (10 and 20 mg/kg), Fluoxetine (5 and 10 mg/kg), Ondansetron (0.1 and 1 mg/kg) and anxiogenic treatments like caffeine (15 and 30 mg/kg) and exposure to immobilization stress. Ethological characterization was done by tracking behavioral pattern of mice on the maze. Results: Diazepam significantly increased the percentage of time spent in the open areas (%TO) and the number of unprotected head dips (uHDIPS), and reduced the number of protected head dips (pHDIPS) and stretch attend postures (SAP) from close to open arm. Similarly, gabapentin significantly increased the %TO and uHDIPS, and reduced the pHDIPS and SAP from close to open arm. Fluoxetine significantly increased the %TO and uHDIPS, and SAP from close to open arm, but it did not have any significant effect on number of pHDIPS. The 5-HT3 receptor antagonist, ondansetron did not produce any significant change in all the behaviors, observed, as compared to vehicletreated control mice. On the other hand, the anxiogenic agent, caffeine and immobilization stress did produce a significant decrease in %TO and the number of uHDIPS, and significantly increased the number of pHDIPS and SAP from close to open arm. Conclusion: The present data indicate that the novel “I - maze” design, pharmacological and ethological analysis provide a sensitive model for detection of anxiolytic/anxiogenic drug action.