Assessment of Vigilance Recovery in Rats Following Anesthesia Using a Touchscreen-Based Continuous Performance Task

Cognitive recovery following general anesthesia is clinically important but incompletely understood. Rodent studies in anesthesia research have primarily examined memory and learning, while vigilance and other neurocognitive domains remain underexplored. To address this gap, we employed the rodent Continuous Performance Task (rCPT), a touchscreen-based translational paradigm, to characterize anesthetic-specific recovery trajectories of vigilance following anesthetic emergence.

Sixteen adult Sprague Dawley rats (8 male, 8 female) were trained to proficiency on the rCPT. Once trained, loss of righting was induced by sevoflurane (3% for 20 min), propofol (10 mg/kg i.v. bolus), ketamine (50 mg/kg i.v. over 10 min), or dexmedetomidine (20 µg/kg i.v. bolus), delivered in a randomized order every other week. Animals were placed supine in the cognitive testing chamber and their performance was recorded for four hours. Return of righting reflex (RORR) was used to indicate anesthetic emergence. Vigilance recovery was defined as 20 consecutive trials with an average hit rate >0.6.

The latency to recover vigilance was delayed following ketamine and dexmedetomidine compared to baseline (Hazard Ratio in ketamine, 5.34; 95% CI, 2.07, 13.76; Hazard Ratio in dexmedetomidine, 5.33; 95% CI, 2.08, 13.62; both p<.0001). Reward retrieval latency recovered 4 hours after RORR following ketamine (percent change from baseline, -24.14%; 95% CI, -54.69, 17.89%) but not recover at the same time point following dexmedetomidine (percent change from baseline, -47.85%; 95% CI, -71.94, -20.23%).

The rCPT identified delayed recovery of vigilance following ketamine and dexmedetomidine. Dexmedetomidine showed prolonged impairment across behavioral measures, including visual processing speed (hit latency) and reward retrieval, suggesting sustained effects on psychomotor function, motor coordination, and behavioral engagement that persisted for at least 4 hours after RORR. These findings support the utility of the rCPT as a translational paradigm for characterizing agent-specific and domain-specific trajectories of cognitive recovery following anesthesia.