Use of the narrow beam test in the rat, 6-hydroxydopamine model of Parkinson's disease

Batteries of behavioural tests provide a method by which researchers may examine specific functional pathways. The narrow beam test examines the ability of a rat to cross a narrow, elevated beam of wood or other material. In order to determine the utility of the narrow beam test in the study of Parkinsonism, it was of interest to characterise the performance of animals at this task. Rats were placed at one end of a 105 cm long, elevated beam and both the time it took to begin crossing the beam, as well as the total time taken to cross the beam, were measured. The effects of training, time of day and 6-hydroxydopamine lesion on beam performance were examined. Rats reached maximal performance at the task within a single test session and time of day had no effect on beam performance. Parkinsonian rats demonstrated a four-fold increase in both the latency to initiate the task and the total time to cross the beam (p < 0.05).