Investigation of the Effect of Cycloserine on Motor Function in a Rat Model of Parkinson’s disease

Background: Previous studies have shown cycloserine to be neuroprotective in some neurodegenerative disorders. Objectives: To investigate the effect of cycloserine on motor function in Parkinson’s disease in a rat model. Materials and Methods: Fifty-six healthy male wistar rats were used in this study 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 model of Parkinson. Also, a healthy group not receiving MPTP or any other drug was considered 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-induced behavioral disturbances, i.e. net number of rotations in AIRT, net biased swing in EBST and reduced rotarod performance time in RPT, more than short period treatment. Although high dose of cycloserine was more effective than its low dose in reducing motor disturbance in initial trials of each test, long period treatment with low dose of cycloserine was similar to long period treatment with a high dose of it in reducing MPTP-induced Parkinsonism in EBST and RPT in latent trials. Conclusion: Long-period treatment with low-dose cycloserine seems to be the best option to obtain a sufficient neuroprotective effect for lowering motor disturbance in Parkinson’s disease.