Glossary

There can be quite a bit of jargon used in scientific articles. We are slowly adding words which we are asked to define or explain in more detail here to our glossary.  If you have a suggestion for a new glossary term, please send us a message on our contact page!

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Astrocytes: Types of glia that support neurons by providing nutrients or through other means.

Ataxia: A loss of muscular control, leading to abnormal walking, speech changes and irregular eye movements.

ATXN1: Ataxin-1 (abbreviated as ATXN1) is a small molecular machine known as a protein. Its function is to guide the creation of other proteins from our DNA blueprint, making it an incredibly important indirect player in a variety of cellular processes. When the gene encoding ATXN1 undergoes a rare mutation that elongates the resulting protein, the result is SCA1.

Autosomal Dominant Inheritance: A condition that requires only one copy of a gene to manifest.

Autosomal Recessive Inheritance: A condition that requires two copies of a gene to manifest.

Basket cells: Inhibitory neurons that transmit information onto Purkinje cell.

Brainstem: The connection between the spinal cord and the brain. Among the many connecting fibers in this brain region, there are a host of processing centers for our most basic physiology: breathing, heart rate, etc. In SCAs, the brainstem experiences degeneration later in disease progression, which is thought to be the cause of premature death in patients.

Cerebellum: A primary area of pathology in the spinocerebellar ataxias. This brain region sits toward the back of the skull and, though small in stature, contains the majority of the nerve cells (neurons) in the central nervous system. Contains the circuits that fine-tune our movements, giving us the ability to move with precision.

Chromosome: A cellular structure that contains all genes. Humans have 23 pairs of these chromosomes. One set is maternal and the other set is paternal.

Climbing Fibers: A type of neuronal fiber which connect two types of neurons, inferior olive neurons and Purkinje cells.

Diplopia: This condition is more commonly known as double vision, where one can simultaneous perceive 2 images of a single object, displaced from each other.

DNA: DNA stands for deoxyribonucleic acid. It is a molecule made up of nucleotides that carries the genetic code in the body’s cells.

Dysarthria: A difficulty speaking, resulting from problems controlling muscles involved in speech.

Gene: A unit of heredity made up of DNA that fully or partially controls the development of specific traits.  

Glia: Non-neuronal cells that primarily responsible for supporting neurons. They are divided into several different types of cells.

Ion channel: A protein complex which allow the movement of ions in and out of cell membranes.

Laser Capture Microdissection (LCM): A technique to cut out a certain cells type of interest from a tissue sample. It is a dissection on a microscopic level.

Mouse Model: A type of animal model with specific characteristics that allow for the study of various aspects of a human disease/condition.

Nystagmus: A condition involving the loss of eye movement control.

Polyglutamine Expansion Disease / CAG-repeat diseasesA family of diseases caused by an expansion of glutamine amino acids in certain proteins.

In about 60 of our genes, there is a DNA code that instructs cells to make small molecular machines (known as proteins) that have large, repeating chemical structures. These structures are made up of the chemical glutamine. While glutamine repeats serve a valuable function under normal conditions, they can also be quite unstable. In polyglutamine expansion disorders, the process of copying these repeating DNA codes becomes disrupted sometime early in development, causing an out-of-control expansion of the number of glutamines that a protein is supposed to contain. Because each gene has a different function, the gene in which a polyglutamine expansion occurs determines which disease a patient has – for example, SCA1 occurs from a polyglutamine expansion in the ATXN1 gene, while Huntington’s disease occurs from a polyglutamine expansion in the IT15 gene.

Protein: A molecule determined by a specific sequence of DNA. These molecules have a specific function in cells, tissues, and organs.

Protein Kinase C (PKC) : A protein that regulates function and survival of cells by phosphorylating proteins in the cells.

Purkinje Neurons: A type of neuron in the cerebellum, which are some of the largest neurons in the brain. They help regulate fine movement. Purkinje cell loss/pathology is a common feature in cerebellar ataxia.

Reactive Oxygen Species (ROS): Reactive molecules that contains oxygen and interact with other molecules in cells. A higher than normal level of these reactive molecules is a source of stress in cells.

Rotarod: The rotarod is a technique that has been used for decades to test motor performance in mice and rats. Researchers place the animal on a rotating cylinder and record how long it takes for the animals to fall off as the rotation speed is gradually increased. The higher the mouse/rat’s motor performance, the longer they will be able to stay on

Stem cells: early developmental cells that duplicate themselves many times and give rise to many different cell types

Transcription: The process in which the genetic information from DNA is copied into RNA, another medium for genetic information.

Transcription Factor: A protein that affect the rate of transcription, effectively turning genes off or on.

Translation: The process after transcription where RNA is converted into a protein sequence.

This page was contributed to by multiple authors and is curated by Carlos Barba.