Modified Irwin Test with Single Intravenous Administration of Caffeine in Mice

Area of Science:

• Neuroscience
• Pharmacology
• Behavioral Science

Background:

• Caffeine is a widely consumed stimulant with known central nervous system (CNS) effects.
• Understanding the precise behavioral impact of caffeine, especially via intravenous administration, is essential for pharmacological research.
• The modified Irwin test provides a standardized method for assessing neurobehavioral parameters in rodents.

Purpose of the Study:

• To investigate the acute behavioral effects of varying intravenous caffeine doses in male ICR mice.
• To quantify changes in motor activity, traction, and respiratory rate following caffeine administration.
• To establish dose-dependent behavioral responses for safe CNS drug testing.

Main Methods:

• Thirty-two male ICR mice were administered intravenous caffeine at doses of 0 (control), 5, 10, or 20 mg/kg.
• Behavioral assessments, including traction, locomotion, and respiratory rate, were conducted at multiple time points (0, 0.25, 1.5, 6, and 24 hours post-injection).
• A modified Irwin test was employed for systematic behavioral observation and scoring.

Main Results:

• Significant alterations in traction and locomotion were observed at caffeine doses of 10 and 20 mg/kg.
• Increased locomotion, characterized by grooming and rapid movement, was evident between 0.25 and 1.5 hours post-administration in the 10 and 20 mg/kg groups.
• Respiratory rate changes were noted exclusively in the 20 mg/kg group during the initial observation period.

Conclusions:

• Intravenous caffeine administration significantly impacts mouse behavior, specifically motor activity and traction.
• The observed effects are dose-dependent, with higher concentrations eliciting more pronounced changes.
• These findings offer valuable data for the safe and effective use of caffeine in pharmacological studies targeting the CNS.