Effect of short-term and chronic caffeine intake on rats with various anxiety level

Effect of one-day and chronic (3 week) drinking of 0.1% caffeine as a single source of fluid on anxiety in rats with different anxiety level (either genetically determined or individually acquired) was studied. When housed in groups, Fisher-344 rats had a significantly higher anxiety level than WAG/G rats. When the rats were housed individually, their anxiety gradually increased. The effect of short-term and chronic intake of caffeine in high doses depended on both genetically determined sensitivity to this agent and environmental factors (social isolation). It was concluded that chronic caffeine drinking does not induce persistent emotional changes similar to drug abuse, because caffeine withdrawal produced little effect on animal anxiety.