Directions: Define key science terms relating to topics in neuroscience, biochemistry and microbiology using contextual clues from “Parkinson’s pathways.” Students can use resources beyond the article to find more information if necessary.

Definitions relating to the article:

What is Parkinson’s disease?

Parkinson’s disease is an incurable brain and nervous system disease in which nerve cells die off in the substantia nigra, a brain region involved in muscle control, causing tremors and affecting movement, memory and mood.

What is Alzheimer’s disease?

Alzheimer’s disease is an incurable brain disease characterized by nerve cell death resulting in progressive memory loss and dementia. The causes of Alzheimer’s are not well understood, but a very visible effect in the brain is tangles or plaques of clumped proteins.

What are neurotransmitters?

Neurotransmitters are chemical signals that nerve cells in the brain use to communicate with each other. Different types of nerve cells in different brain regions produce different neurotransmitters.

What is alpha-synuclein and what role does it play in the body?

Alpha-synuclein is a protein mainly found in nerve cells and its normal role is not well understood. Misfolded alpha-synuclein can form clumps and hinder communication between cells.

What are Lewy bodies? What role do Lewy bodies play in Parkinson’s disease?

Lewy bodies are large clumps of alpha-synuclein and other proteins that accumulate in the brains of people with Parkinson’s disease and Lewy body dementia.  

What is amyloid? Name a disease which is closely associated with amyloid buildup.

Amyloids are clumps of proteins that form when proteins misfold and become tangled together. Various proteins can form amyloids, which can build up in the brain to form plaques — a hallmark of Alzheimer’s disease.

What is the human microbiome? Name a common bacteria that lives in the human body and describe its function.

The human microbiome is the population of bacteria and other microorganisms that live on and inside a person. One type of bacteria commonly found in the human microbiome is Escherichia coli. In the gut, E. coli can help prevent pathogenic bacteria from taking hold. But some strains of E. coli can also cause gut inflammation.

What is a biofilm? Give an example of a biofilm that exists in/on the human body.

A biofilm is a population of microorganisms that stick together by producing a “film” or extracellular matrix of sugars, proteins and fats. Biofilms strongly adhere to surfaces and can be very difficult to remove. An example of a biofilm is dental plaque, which is formed by bacteria on teeth.

What are prions? Name a disease caused by a prion.

Prions are misfolded proteins that can cause disease. Prions can form clumps in the brain and cause memory impairment, affect movement and personality. An example of a prion disease is bovine spongiform encephalopathy, or mad cow disease.

Discussion beyond the article:

What is a current treatment for Parkinson’s disease?

Current treatments focus on controlling symptoms. The drug Levodopa is a chemical that once in the brain converts into the neurotransmitter dopamine. Other drugs that activate nerve cells’ dopamine docking stations can also be given. Deep brain stimulation is a surgical treatment in which electrodes are implanted in a specific brain region to help control movement.

What is amyotrophic lateral sclerosis (ALS)?

In ALS, motor neurons in the brain’s muscle control region and spinal cord die. Early symptoms include muscle stiffness, weakness, twitching, cramps and atrophy. As the disease progresses, patients gradually lose the ability to move, speak, swallow and breathe. The causes of ALS are not well understood.

What is chronic traumatic encephalopathy (CTE)?

CTE is a disorder diagnosed after death that’s associated with memory loss, emotional outbursts, depression and dementia. The disorder appears to be initiated by repeated head injuries, such as those received by some athletes or soldiers. Over many years after the initiating events, nerve cells in the brain become progressively damaged and die. The mechanisms by which CTE develops are not well understood. However, one apparent hallmark is that tau proteins begin to form tangles, often seen in other degenerative brain diseases.

What are tau proteins?

Tau proteins, mainly found in nerve cells in the brain, help stabilize scaffolds that give cells their proper shape and help cells move. If a tau protein becomes misfolded, it can form clumps and alter brain function.

What are tumor necrosis factors (TNFs) and antitumor necrosis factors?

Tumor necrosis factors are signals that trigger inflammatory reactions in cells in response to an injury or infection. Antitumor necrosis factors are anti-inflammatory drugs that interfere with TNF signaling between cells. Such drugs can reduce inflammation or prevent undesirable responses from the immune system.

What are stomach ulcers?

Ulcers are sores that occur in the lining of the stomach and small intestine. Many stomach ulcers are caused by the bacteria Helicobacter pylori and can be cured with antibiotics.

What is Crohn’s disease?

Crohn’s disease is an inflammatory bowel disease that causes tissue damage in the gastrointestinal tract. The exact cause of Crohn’s disease is unknown, but a number of factors such as heredity, a malfunctioning immune system and even the gut microbiome likely play a role in the disease’s development. Crohn’s disease can be treated with steroids and immunosuppressant drugs.