Written By: Mayukha Kashyap
Picture source: https://www.cdc.gov/parasites/toxoplasmosis/biology.html
Parasites are generally viewed as dangerous. They can alter cells’ physical composition and their interactions in the human body, leading to long-lasting effects. They can also travel through the body and into the brain, resulting in death or permanent brain damage. Like viruses, parasites infect a host and damage the body’s internal organs, sometimes without the host realizing it. In these severe cases, the parasite can kill the host. A parasitic relationship is established between the host body and the parasite itself: the parasite can leave and get food from the host’s body, but the host’s body sustains damage. In other words, there is no gain for the host, but there is a gain for the parasite. So how can parasites be used positively if they cause so much damage?
To develop cures for diseases, scientists have to be creative. For example, scientists can implant stem cells into the bone marrow to replace damaged cells with brand new ones through research. Stem cells are unique because they can grow into any body cell if placed in the right condition. This is often used when doing transplant surgeries; in the bone marrow, the stem cell can replace the damaged red blood cells by growing into healthy ones. For diseases where there is no cure yet, such as cancer, innovative research such as this helps saves lives. Schizophrenia is a mental illness that affects how people live. There is no cure, and patients often “hear voices in their head” that, at times, can tell them to commit serious crimes. Those with Schizophrenia have to undergo lifelong treatment and often disconnect from reality.
New research by the University of Leeds shows how a parasite may help those with Schizophrenia. The T.gondii parasite that causes the disease Toxoplasmosis affects a person’s mental state by lowering the amounts of norepinephrine present. Norepinephrine is released by the brain as a stress signal and is associated with diseases such as Schizophrenia. Reducing the amounts of norepinephrine in the body can, therefore, alter the brain’s cognitive synapses. Toxoplasmosis affects around 2.5 million people globally, and while it is usually asymptomatic, people have reported feeling nauseous and experiencing headaches, confusion, and seizures.
T.gondii only sexually reproduces in cats by forming cysts but can make its way into the human body by transmitting the cysts. These cysts are present in cats’ feces and can come into human contact through soil or eating unprocessed meat. T.gondii then makes its way to the brain, where it forms cysts and lays dormant up to the end of a person’s life. During its dormant period, the parasite can lower the norepinephrine amounts. While there is not enough known about the norepinephrine response, researchers at the University of Leeds are trying to understand more about its connection to Schizophrenia. If the parasite lowers norepinephrine amounts, then theoretically, it could be used as a potential treatment option for Schizophrenia patients.
According to Glenn McConkey, Associate Professor of Heredity, Disease, and Development at Leeds' School of Biology, researchers are toying with two theories about Toxoplasmosis and its effects on behavior. “One school believes that behaviour changes are invoked by the immune response to infection, and the other that changes are due to altered neurotransmitters,” says McConkey. However, McConkey believes that more research can be done about the parasite, leading to potential treatment options for those with diseases such as Schizophrenia.
Works Cited:
Conor Laing, Nicolas Blanchard, Glenn A. McConkey. Noradrenergic Signaling and
Neuroinflammation Crosstalk Regulate Toxoplasma gondii-Induced Behavioral Changes.
Trends
in Immunology, 2020; DOI: 10.1016/j.it.2020.10.001
University of Leeds. "Parasite infection discovery could assist mental health treatments."
ScienceDaily. ScienceDaily, 16 November 2020.
<www.sciencedaily.com/releases/2020/11/201116112914.htm>.