Age and anxiety: Increased anxiety, decreased anxiolytic, but enhanced sedative, response to chlordiazepoxide in old rats
✍ Scribed by S. E. File
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 414 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0885-6222
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✦ Synopsis
The effects of chlordiazepoxide (7.5 mg/kg) were assessed on the performance of young (3 months) and old (12 months) hooded Lister rats in the elevated plus-maze test of anxiety. In young animals chlordiazepoxide significantly increased the percentage of entries onto open arms and the percentage of time spent on the open arms of the plus-maze, measures that reflect its anxiolytic action. In the young animals this dose of chlordiazepoxide did not change the total number of arm entries, a measure that reflects its sedative action. However, in the old animals the only significant effect was a reduction in total arm entries. The effects of ageing on performance in the plus-maze was assessed by testing rats at 3,6,9 and 12 months of age. Between 9 and 12 months the rats showed a significant decrease in the percentage of entries onto open arms and in the percentage of time spent on the open arms, indicating an increase in this measure of anxiety. Thus it seems that old rats might have an increase in their baseline measures of anxiety, coupled with a reduced anxiolytic response to benzodiazepines.