Parkinson’s Disease (PD) affects millions of lives daily, driving a current emphasis on research in this field. BMC Neuroscience defines PD as “a pervasive motor disorder resulting from the depletion of dopamine (DA) in the nigrostriatal region of the central nervous system” (Wang et al., 2012). This depletion of dopamine is caused by defective proteins that misfold, lose their function, and die off. Motor functions are highly affected by this disruption, gait specifically.
Mice, a quadruped rodent, walk using opposing diagonal feet, rotating to create strides. Scientists are able to document these steps using systems that measure length, patterns, force, and speed of strides. One example of these tests is a Catwalk. Through this, it can be seen that mice with the Parkinson’s protein defect have a shuffled gait and struggle to follow the pattern of alternating limbs.
In Figure 2 of the BMC Neuroscience article titled Quantitative assessment of gait and neurochemical correlation in a classical murine model of Parkinson’s disease, gait stride and frequency are measured using the Catwalk test (Wang et al., 2012). The control group consists of mice without Parkinson’s disease, and the PD group represents individuals with the condition. It can be seen that strides are shorter and less evenly distributed among paws. These changes are not random, and all exemplify key changes the disease spurs within the neurological system.
How Does Parkinson’s Affect The Neurological System?
The reason that this protein defect in the brain causes these motor deficits comes from the different regions that it targets. One region is the basal ganglia, located in the cerebrum. Those who have studied neurology before may recall that this section of the brain is where voluntary movement is controlled; therefore, damage to this area can lead to significant problems, such as slower speed, shorter and scattered steps, and a narrower base of support (Kurz, 2008). Parkinson does not only affect one region.
Central Pattern Generators are defined as, by ScienceDirect, “neuronal circuits that when activated can produce rhythmic motor patterns” (Marder, 2001). When these circuits are blocked and prevented from working, signals for motor functions, such as walking, are not able to be successfully processed. This explains why mice have a hard time with consistent footprints.
How Does This Connect To Humans?
Over the years, mice have been used to study diseases affecting humans because of their similar genetic traits and ease of replication. These patterns seen in the mice’s gait and neurological damage are also seen in human patients with trouble with controlled motor functions. Common symptoms of Parkinson’s Disease include tremors and difficulty performing daily tasks. Although alternative technological advancements to aid in these issues are available, it can still be daunting for an individual. This, combined with a depletion in dopamine, can lead to severe mental health problems, such as depression and anxiety. The more researchers, communities, families, and individuals learn about this disease, the more they can work together to create a positive environment conducive to safety, comfort, and growth.
What Are Some Current Gaps In This Research?
With understanding how PD affects gait and the neurological system, there is still so much researchers and scientists have yet to discover about the disease. One example of this is seen through the different classifications for PD. For many years, this disease has been viewed as something that works systematically, almost identical in all diagnosed cases, but recently, it has been seen that different forms of this are present in individuals, leading to new research being formed about various subtypes.
Another gap scientists have recognized is the understanding of how Parkinson’s starts and spreads from cell to cell. It is understood that there is a progression of damage and symptoms over time, leading to diagnoses in later stages of life. They have classified certain environmental factors as significant influences, but the knowledge of which specific factors and the process involved are still partially unknown. This is why science is filled with numerous questions to find the answers to these gaps.
Parkinson’s disease has a significant impact on a large number of individuals, giving importance to current research and awareness surrounding it. Understanding how neurological depletions lead to motor disorders, such as shuffled and slowed gait, and how scientists can use mice to discover more about this disease is essential. When patterns can be recognized in studies, that is where results will prevail. Gaps in research will also continue as more information is discovered. The importance is that questions are persistently asked and there is a constant effort to uncover the truth.
References
Kurz, M. J., Pothakos, K., Jamaluddin, S., Scott-Pandorf, M., Arellano, C., & Lau, Y.-S. (2007). A chronic mouse model of Parkinson’s disease has a reduced gait pattern certainty. Neuroscience Letters, 429(1), 39–42. https://doi.org/10.1016/j.neulet.2007.09.060
Marder, E., & Bucher, D. (2001). Central pattern generators and the control of rhythmic movements. Current Biology, 11(23), R986-96. https://doi.org/10.1016/s0960-9822(01)00581-4
Wang, X. H., Lu, G., Hu, X., Tsang, K. S., Kwong, W. H., Wu, F. X., Meng, H. W., Jiang, S., Liu, S. W., Ng, H. K., & Poon, W. S. (2012). Quantitative assessment of gait and neurochemical correlation in a classical murine model of Parkinson’s disease. BMC Neuroscience, 13(1), 142. https://doi.org/10.1186/1471-2202-13-142