Effects of the benzodiazepine receptor inverse agonist Ro 15-4513 on the ingestion of sucrose and sodium saccharin solutions: a microstructural analysis of licking behavior.

The effects of the benzodiazepine receptor partial inverse agonist Ro 15-4513 on consumption of either a 1% sucrose solution or a 0.1% sodium saccharin solution in nondeprived male rats was examined. A video-recording approach was adopted in which licks were counted in a frame-by-frame analysis. Ro 15-4513 (1-10 mg/kg) caused a significant decrease in the intake of both sucrose and saccharin solutions that was associated with a reduction in the initial rate of licking. There was a decrease in the total duration of drinking, total licks, and number of bouts for both sucrose and saccharin. For sucrose, mean bout duration was significantly reduced, although this was not so for saccharin. Intrabout lick rate, the latency to engage in drinking, and the postdrinking time were not affected for either sucrose or saccharin. These data are consistent with previous evidence that strongly suggests that benzodiazepines influence palatability.