ABSTRACT
BACKGROUND: Assessment of the ability of rat to balance by rotarod apparatus (ROTA) is frequently used as a measure of impaired motor system function. Most of these methods have some disadvantages, such as failing to sense motor coordination rather than endurance and as the sensitivity of the method is low, more animals are needed to obtain statistically significant results. NEW METHOD: We have designed and tested a new designed apparatus (NDA) to measure motor system function in rats. Our system consists of a glass box containing 4 beams which placed with 1cm distance between them, two electrical motors for rotating the beams, and a camera to record the movements of the rats. The RPM of the beams is adjustable digitally between 0 and 50 rounds per minute. RESULTS: We evaluated experimentally the capability of the NDA for the rapid measurement of impaired motor function in rats. Also we demonstrated that the sensitivity of the NDA increases by faster rotation speeds and may be more sensitive than ROTA for evaluating of impaired motor system function. COMPARISON WITH EXISTING METHODS: Compared to a previous version of this task, our NDA provides a more efficient method to test rodents for studies of motor system function after impaired motor nervous system. CONCLUSIONS: In summary, our NDA will allow high efficient monitoring of rat motor system function and may be more sensitive than ROTA for evaluating of impaired motor system function in rats.
Subject(s)
Diagnostic Techniques, Neurological/instrumentation , Movement Disorders/diagnosis , Analysis of Variance , Animals , Central Nervous System Depressants/toxicity , Disease Models, Animal , Dose-Response Relationship, Drug , Ethanol/toxicity , Male , Movement Disorders/etiology , Postural Balance/drug effects , Postural Balance/physiology , Psychomotor Performance/drug effects , Psychomotor Performance/physiology , Rats , Rats, Wistar , Rotarod Performance Test/instrumentation , Rotarod Performance Test/methodsABSTRACT
Progesterone (PROG) is promising as an important protective agent against various injuries to the nervous system. The present study was designed to investigate whether starting PROG administration, when symptomatology is already established, would alleviate the expression of nociceptive behaviors (mechanical allodynia and thermal hyperalgesia) and electrophysiological changes in a chronic constriction injury (CCI) model of neuropathic pain in rats. Male rats were given PROG (1.5, 3, 6 and 12 mg/kg, i.p.) 12 days after CCI induction, and dosing continued daily until day 26. Behavioral tests were done immediately before surgery (day 0) and on days 12, 26, 28, and 35 post-CCI, and were followed by electrophysiological measurements in the last day. PROG at doses of 6 or 12 mg/kg reduced both the thermal hyperalgesia and mechanical allodynia induced by CCI. Electrophysiological data indicated that CCI-induced animals had a remarkable decrement of both compound muscle and nerve action potential amplitudes recorded in the gastrocnemius muscle and sural nerve, respectively. CCI also caused a significant reduction in motor and sensory conduction velocities measured in the sural and tibial nerves, respectively. PROG at doses of 6 or 12 mg/kg induced a significant recovery of all electrophysiological changes. Our data indicated that starting PROG therapy when symptomatology is already established, and continuing it for a sufficient period of time, may have a therapeutic effect. This suggests that PROG may offer new strategies for the treatment of neuropathic pain.
