acetylation: a reaction that adds an acetyl functional group to a molecule; acetyl groups can turn proteins on and off

amyloid plaque: a clump of insoluble protein (amyloid-β) that accumulates in the brain tissue of patients with Alzheimer’s disease

amyloid-beta (amyloid-β, Aβ, Abeta): a protein formed when amyloid precursor protein (APP) is cut by enzymes; its normal function is not well known

atrophy: wasting away or shrinking; neuronal atrophy is the loss of neurons

autophagy: a process by which cells break down unnecessary or dysfunctional cellular components through the actions of enzyme-filled lysosomes

aphasia: a loss of the ability to produce and/or understand language

apraxia: the loss of the ability to perform tasks that require remembering sequences of movements (like waving goodbye)

ataxia: shaky movements, wobbliness, unsteady walk and clumsi- ness usually caused by dysfunction of the cerebellum, a part of the brain which controls movement


biological replicate: unique samples collected from the same subject, such as two lines of iPS cells generated from two differ- ent collections from the same person; different from a technical replicate, where all subsequent samples are generated from a single starting material, such as two lines of iPS cells derived from one original collection


C. elegans: Caenorhabditis elegans is a non-parasitic roundworm, about 1 mm in length; one of the simplest organisms with a nervous system

cellular inclusion: any small entity found within a cell

central nervous system: a general term used to describe the brain and spinal cord; in contrast to the peripheral nervous system that includes all the nerves and ganglia outside of the brain and spinal cord

cerebral cortex: the outer portion of the brain made up of grey matter (neuronal cell bodies, neuropil, glial cells and capillaries)

cerebrospinal fluid (CSF): the clear, watery liquid that bathes and protects the brain and spinal cord

chromosome: strands of DNA compressed and organized into a double helix structure; humans typically have 23 pairs of chromosomes

chromosome 17q21 (FTDP-17): the chromosome that contains the gene for making the protein tau

chronic traumatic encephalopathy (CTE): a degenerative brain disease seen in some people who have had multiple concussions or multiple traumatic impacts to the head

cortex: the outer portion of an organ; in the brain, the outer layer is the cerebral cortex


delirium: a sudden onset of severe confusion and disorientation that fluctuates

dementia: a decline in cognitive function that leaves a person unable to carry out daily activities of life; affected abilities can be cognitive (memory, concentration, judgment, etc.), emotional, physical, and behavioral; a symptom of neurodegenerative disease

dendrites: the branched projections of a neuron that receive the electrochemical signal from other neurons which then passes through the cell body (soma), down the axon, and across the synapse to the next neuron

DNA (deoxyribonucleic acid): the complex molecule that holds the “blueprint” instructions for your body to make proteins

dysphagia: difficulty in swallowing due to problems in nerve or muscle control

dystonia: involuntary, sustained muscle contractions that fre- quently cause twisting body motions, tremor, and abnormal posture (these movements may involve the entire body or only an isolated area)


endogenous: produced or caused by factors within the organism or system; the opposite of exogenous (from outside the organism)


frontal lobes: the front part of the brain that regulates higher intellectual functions like emotions, cognition, error detection, volition, and a sense of self to create our social brain

frontotemporal dementia (FTD): the umbrella term for the clinical syndromes of behavioral variant frontotemporal dementia (bvFTD), semantic variant primary progressive aphasia (svPPA) and non-fluent/agrammatic variant primary progressive aphasia (nfvPPA); these syndromes share involvement of the frontal and temporal lobes of the brain; the term is also sometimes used to refer specifically to bvFTD

frontotemporal lobar degeneration (FTLD): the term that describes the specific pathological diseases that result in FTD clinical syndromes; subtyping is based on the specific proteins found within the neuronal inclusions


gait: how a person walks

gene: a specific subunit of DNA that codes for a specific protein

genotype: the genetic makeup of a cell or an organism

gliosis: a process leading to scarring in the central nervous system that involves the production of a dense fibrous network of neu- roglia (supporting cells) in the damaged areas; gliosis is promi- nent in many diseases of the central nervous system, including frontotemporal dementia, Alzheimer’s disease, multiple sclerosis and stroke

grey matter: the outermost layer of the brain (and some deep structures) which contains nerve cell bodies and is primarily asso- ciated with processing and cognition; it is so named because it appears gray, in contrast to the white matter, the part of the brain that contains myelinated nerve fibers that relay and coordinate communication between different brain regions


hyperreflexia: an abnormal, increased action of the reflexes; a reaction of the autonomic (involuntary) nervous system to stimulation


induced pluripotent stem cells (iPSCs): adult cells that have been genetically reprogrammed to an embryonic stem cell-like state and can, therefore, become other types of cells such as neurons

isogenic: having the same genes, i.e. identical twins


knockout (KO) cells/mice: a genetic technique in which both of an organism’s genes are made inoperative (a heterozygous knockout or het has only one of the two alleles knocked out)


lysosome: a waste-disposal organelle inside the cell that uses enzymes to break down unnecessary or dysfunctional compo- nents for recycling


microtubules: a key structural element of the cell structure (cyto- skeleton); healthy tau protein stabilizes microtubules

mutation: a permanent change in the DNA or RNA—the molecular “blueprints” that direct the building of proteins; muta- tions can be helpful, neutral, or harmful and can be inherited, caused randomly or caused by environmental factors

myoclonus: sudden, involuntary jerking or twitching of a muscle or group of muscles


neurofibrillary tangle: pathological clusters of the protein tau that are found within neurons; found in tauopathies and Alzheimer’s disease (in association with amyloid plaques)

neuronal inclusion: any small entity found within a neuron (nerve or brain cell); identifying the inclusion helps to diagnose the disease


pathology: the study and diagnosis of disease through examina- tion of organs, tissues, bodily fluids or whole bodies

pedigree: in medicine, a family health history diagrammed with a set of international symbols to indicate the individuals in the family, their relationships to one another, those with a disease, etc.

phenotype: the traits of an organism

phosphorylation: the addition of a phosphate group to a protein or other organic molecule, which can turn on and off enzymes, thereby altering their function and activity

Pick bodies: a specific type of neuronal inclusion made up of the protein tau and seen in some people with FTD

Pick’s disease: the pathological subtype of behavioral variant frontotemporal dementia (bvFTD) with Pick bodies present

prion: an infectious agent made up of abnormally folded protein and no genetic material that induces other normal prion proteins to misfold into rogue prions; discovered by Dr. Stanley Prusiner

proband: an individual affected with a disorder who is the first subject in a study of family lineage and heritability

prodromal symptom: an early, often non-specific symptom that may be a warning sign of disease


sign: an indication that something is not right in the body; defined as things that can be seen by a doctor, nurse or other health care professional; fever, rapid breathing rate and abnormal breathing sounds may be signs of pneumonia

symptom: an indication of disease, illness, injury or that some- thing is not right in the body; symptoms are felt or noticed by a person, but may not easily be noticed by anyone else; chills, weakness, shortness of breath, and a cough may be symptoms of pneumonia


tau: a protein in the body that aids in the cellular structure (cyto- skeleton), communication, and transportation

tauopathy: a class of neurodegenerative diseases associated with the pathological aggregation of tau protein in the human brain

technical replicate: samples generated from a single starting material, such as two lines of iPS cells derived from one original collection or one brain culture treated with drug, then split into 3 parts and each part measured for the same outcome; different from a biological replicate, where different samples are collected from the same source at different times

temporal lobes: the lobes of the brain located on the sides of the brain near the ears; they contain the auditory cortex which is responsible for hearing, language comprehension, and memory


white matter: the part of the brain that contains myelinated nerve fibers; the white matter looks white because of myelin, the insula- tion covering the nerve fibers that helps to speed up neuronal signals; the white matter connects areas of the brain together

wild type: the predominant phenotype, genotype, or gene that occurs in a natural population of organisms (in contrast to mutated forms)


zinc finger: a small protein in which zinc helps the protein fold more tightly than it could with only hydrogen bonds; they are frequently used to change DNA sequences

A to Z and everything in between.