Abstract
Diazepam is a widely prescribed benzodiazepine used in the acute treatment of anxiety, however its dose-dependent effects on cognition remain inconsistent in the literature. The current study investigated the acute effects of diazepam on the cognitive processes of sustained attention and working memory. Five male and five female rats were trained on two cognitive tasks in operant chambers. The rats were trained to press the correct lever in response to its corresponding light cue being presented. In the sustained attention task cue duration was manipulated, and in the working memory task delay duration was manipulated. Once the rats were performing the task successfully, diazepam was administered across doses ranging from saline (0mg/kg) - 2.0mg/kg to examine the dose-response effects on these tasks. The results showed that sustained attention accuracy decreased as cue duration shortened, and working memory accuracy decreased as delay duration increased. The results also found that sustained attention accuracy was systematically affected by diazepam, where an increase in dose of diazepam caused a reduction in proportion correct. This effect was also found to be modulated by sex as a significant interaction between sex and dose was observed, with male rats showing dose-dependent reductions in attention accuracy, while female performance remained relatively stable across doses. Diazepam effects were also not due to the rats experiencing sedation, as the latency to respond and retrieve did not change with changes in diazepam dose. In contrast, working memory performance was not found to be affected by diazepam dose or sex. These findings contribute to the understanding of how acute diazepam administration can affect different cognitive processes, demonstrating selective impairment of sustained attention in the absence of working memory disruption at the doses tested. The observed sex differences also highlight the importance of considering individual variability when assessing the cognitive effects of diazepam, and provide further evidence relevant to the clinical prescription of benzodiazepines.