Reza Taherian - MD, Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences,Tehran, Iran
Mehran Arabahmadi - MD, Brain Mapping Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Mahdi Taherian - MSc, School of Medicine, Semnan University of Medical Sciences, Tehran, Iran

Background: Previous studies have shown cycloserine to be neuroprotective insome neurodegenerative disorders.Objectives: To investigate the effect of cycloserine on motor function inParkinson’s disease in a rat model.Materials and Methods: Fifty-six healthy male wistar rats were used in thisstudy and were divided into seven groups according to receiving saline, low dose(i.e. 100 mg/kg) and high dose (i.e. 200 mg/kg) of cycloserine for a short period(i.e. 8 days) (groups A-C, respectively) or long period (i.e. 16 days) (groups D-F,respectively) in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-rat modelof Parkinson. Also, a healthy group not receiving MPTP or any other drug wasconsidered as the control group (group G). Apomorphine-induced rotational test(AIRT), elevated body swing test (EBST) and rotarod performance test (RPT)were done to examine behavioral performances.Results: Long-period treatment with cycloserine reduced MPTP-inducedbehavioral disturbances, i.e. net number of rotations in AIRT, net biased swing inEBST and reduced rotarod performance time in RPT, more than short periodtreatment. Although high dose of cycloserine was more effective than its low dosein reducing motor disturbance in initial trials of each test, long period treatmentwith low dose of cycloserine was similar to long period treatment with a highdose of it in reducing MPTP-induced Parkinsonism in EBST and RPT in latenttrials.Conclusion: Long-period treatment with low-dose cycloserine seems to be thebest option to obtain a sufficient neuroprotective effect for lowering motordisturbance in Parkinson’s disease.

Parkinson Disease; Cycloserine; Behavior; Motor Skills