Zebrafish Five-Choice Serial Reaction Time Task

The zebrafish five-choice serial reaction time task (5-CSRTT) is an aquatic adaptation of the widely used rodent 5-CSRTT originally developed by Robbins and colleagues for measuring sustained attention and executive function. The apparatus consists of a trapezoidal operant chamber submerged in system water, with five recessed stimulus apertures arranged along one curved wall, each equipped with a high-intensity white LED visible through the water column. A food delivery zone at the opposite end dispenses liquid larval food or brine shrimp nauplii as reinforcement. This protocol has been validated in adult zebrafish (Danio rerio) to model attention-deficit and impulse-control phenotypes relevant to ADHD, schizophrenia, and substance use disorders.

Each trial begins with an inter-trial interval during which all LEDs are off and the fish must wait in the rear magazine area. After the ITI elapses, one of the five apertures is illuminated for a defined stimulus duration (typically 5-10 seconds for initial training, titrated down to 1-2 seconds at asymptotic performance). The fish must swim to the illuminated aperture within a limited hold period to register a correct response and trigger food delivery. Premature responses (entering any aperture during the ITI) are punished with a timeout period during which the house light is extinguished. Omissions (failure to respond within the limited hold) advance to the next trial without reward. Perseverative responses (repeated nose-pokes into the same aperture after a correct response) are recorded as a measure of compulsive-like behavior.

ConductMaze provides fully automated control of all trial events including LED stimulus presentation with millisecond timing precision, overhead camera-based fish position tracking using centroid detection algorithms, automated food reward delivery via peristaltic micropump, and real-time classification of responses as correct, incorrect, premature, omission, or perseverative. The software implements adaptive training schedules that automatically progress the fish through shaping stages based on individualized performance criteria, reducing the typical 3-4 week training period. Session data including accuracy, omission rate, premature response rate, perseverative index, and response latency distributions are computed in real time and exported for statistical analysis.