This research will begin with the definition of Parkinson’s disease commonly referred to as PD as one of the most common neurodegenerative diseases. PD affects mostly the neurons located in the nervous system. The affected neurons located in the basal ganglia cavity get deteriorated affecting the normal functions of the nervous system resulting in rigidity, tremor, and bradykinesia. The resulting PD conditions get worse with age making it complicated to treat and control. More studies have to be conducted in an effort to come up with better strategies to counteract the disease. In order to identify different treatment methods, the pathology of the disease has to be understood which has also proved to be a complex process. Studies conducted earlier have failed to identify the main factors behind PD irregular form making it almost impossible to come up with a single method of treating the disease. Parkinson’s condition normally affects the dopaminergic cells located in the substantial nigra region by altering their normal activity of secreting dopamine. Dopaminergic cells form part of the neural circuits and once the circuit inside the basal ganglia is affected, the process of regulating movement will be inhibited. The movement regulation process involves both the indirect and direct pathways which are responsible for inhibiting and facilitating movement respectively. This implies that when the dopaminergic cells are lost, the disease condition will result in a movement disorder. PD results to the loss of more the 70% of the dopamine cells at its onset which is later followed by dopamine terminals asymmetric loss taking place in the striatum.
When a patient is affected by PD, his or her circuitry balance in normally lost. Such loss comes about as a result of dopamine depletion. The parts that are affected in this case are the indirect and direct pathways whose nuclei are responsible for inhibiting the thalamus. When the activities of these nuclei found in the pathways increase, the inhibition process is consequently increased reducing the normal movement of a person.
Another conditions resulting to the disease is the degeneration process that takes place in the presence of proteinaceous inclusions, which include; intracytoplasmic and Lewy bodies (LBs) (Blandini 1). The Lewy bodies are located in the brain cells and consist of different types of proteins which after degenerating they give rise to the PD conditions affecting the brain and the nervous system. The LBs can be easily identified when they affect the brain cells as they are spherical in shape with a core that is central and granular with a fibrillary halo surrounding it as shown in figure 1 bellow. The SNC activities are responsible for some of the PD symptoms including movement execution, tremors and muscle rigidity (Blandini 6).
Figure 1 showing a Lewy body located in the brain cell (Cuerda 102).
The death of Nigral cells is normally facilitated by the presence environmental toxins and the reduced number of Nigral cells consequently results in protein aggregation and mitochondrial defects (Blandini 1). The death of nigral cell is thus one of the main causes of neuron degeneration. Some of the factors leading to nigral cell death through abnormal apoptosis regulation include; impaired mitochondrial activities, proteasomal impairment or glutamate receptors excessive stimulation (Cuerda 102).
Several methods of treating and controlling PD have been proposed. Among the many strategies is the L-3, 4-dihydroxyphenylalanine (L-DOPA) which is the oldest and the mostly commonly used (Schapira 102). L-DOPA treatment targets nervous system barrier between the brain and blood forming a reduced section of the brain as shown in the figure bellow. Once in the brain, L-DOPA is converted to the dopamine where it is broken down to form various systems of enzymes in the brain.