Objective: To explore an improved operation approach to make up the ethical deficiency of classical bipedal rat model.
Methods: 20 SD rats were randomly divided into an improved group and a traditional group averagely. Improved group were operated with plexus brachialis nerve amputation, while traditional group with forelimbs amputation close to shoulder joint. Forelimb and shoulder joint movements were observed and electromyography of the peripheral muscles around shoulder joint were recorded to make certain the paralytic scope. Operation duration and axillary artery hurt probability of both the improved and traditional operation were compared to evaluate the operation risk of improved approach. Mean total upright time on 2 d, 1 w, 2 w, 4 w and 6 w post-operation and upright posture on 6 w post-operation were recorded to evaluate the human-upright-posture-simulating effect of bipedal rats operated with improved approach.
Results: Compared with classical amputation approach, improved approach exhibited simpler operation procedure, shorter operation duration and lower axillary artery hurt probability. Electromyography revealed that all forelimb muscles and most shoulder-peripheral muscles were denervated, forelimbs of the improved bipedal rats were absolutely paralyzed and shoulder joint reserved only slight abduction function. The mean total upright time of improved bipedal rats was longer than the classical ones after 2 w post-operation, while upright posture showed no difference with classical bipedal rats.
Conclusions: The improved operation approach not only simplified operation procedures, but also achieved even better effect than classical amputation operation and exempted bipedal rat model from the ethical shadow.