The Development of Treatment for Parkinson’s Disease

Parkinson’s disease (PD) is a slowly progressive, age-related, second most common neurodegenerative disorder after Alzheimer’s disease of unknown etiology. Dopamine replacement therapies were introduced five decades ago and still remain the mainstay of treatment for Parkinson’s disease. However, with long-term treatment with L-dopa, more than 50% of patients were found to develop motor response complications approximately after 4 - 5 years of initiation of continuous treatment, in 80% of patients treated for 10 years, and in nearly 100% patients with young-onset disease. The complications of long–term treatment with levodopa include-motor fluctuations, dyskinesias, and nonmotor fluctuations are such as mood disturbance, cognitive dysfunction, dysautonomia and pain. Till date, there are various therapeutic approaches having been developed for the treatment of advanced PD comprising Pharmacotherapy, neurotrophic factors, surgical procedures such as DBS, cell-based therapies and gene therapies. The pharmacological and surgical therapies are only aiming to improve the symptoms of PD, but none are proven to have a significant effect on the underlying disease process with respect to either slowing disease progression or restoring the affected dopaminergic neurons. Although there is no cure for PD, Gene based therapy has significant prospective advantages over the conventional treatment modalities for PD, as it could theoretically be used to preserve or restore dopaminergic neurons affected by PD through the action of neurotrophic factors or alternatively increase the availability of enzymes required for dopamine synthesis. All commonly employed PD therapies focus on the amelioration of symptoms and do not cure disease. In this review only we summarize the newer therapeutic strategies for the treatment of PD such as anti-inflammatories, neurotrophic factors, neurosurgical procedures (DBS), cell based therapies and gene therapies.

Express=on of Brain-derived Neurotrophic Factor and Tyrosine Kinase B in Cerebellum of Poststroke Depression Rat Model

Background： The pathophysiology of poststroke depression （PSD） remains elusive because of its proposed multifactorial nature. Accumulating evidence suggests that brain-derived neurotrophic factor （BDNF） plays a key role in the pathophysiology of depression and PSD. And the cerebellar dysfunction may be important in the etiology of depression; it is not clear whether it also has a major effect on the risk of PSD. This study aimed to explore the expression of BDNF and high-affinity receptors tyrosine kinase B （TrkB） in the cerebellum of rats with PSD. Methods： The rat models with focal cerebral ischemic were made using a thread embolization method. PSD rat models were established with comprehensive separate breeding and unpredicted chronic mild stress （UCMS） on this basis. A normal control group, depression group, and a stroke group were used to compare with the PSD group. Thirteen rats were used in each group. Immunohistochemistry and reverse transcription-polymerase chain reaction （RT-PCR） for detecting the expression of BDNF and TrkB protein and mRNA in the cerebellum were used at the 29th day following the UCMS. Results： Compared with the normal control group and the stroke group, the number of BDNF immunoreactive （IR） positive neurons was less in the PSD group （P 〈 0.05）. Furthermore, the number ofTrkB 1R positive cells was significantly less in the PSD group than that in the normal control group （P 〈 0.05）. The gene expression of BDNF and TrkB in the cerebellum of PSD rats also decreased compared to the normal control group （P 〈 0.05）. Conclusions： These findings suggested a possible association between expression of BDNF and TrkB in the cerebellum and the pathogeuesis of PSD.