Physiology Final Exam

Huntington’s Disease (HD)

A hereditary neurodegenerative disorder caused by the expansion of CAG repeats in the HTT gene.

CAG repeats

A sequence of three nucleotides that are repeated multiple times in the HTT gene.

HTT gene

The gene that encodes that Huntington protein

Huntington protein

A protein that is involved in in the development and function of the brain

misfolding

a process in which a protein fold incorrectly, leading to the formation of toxic aggregates

aggregates

clumps of misfolded proteins that can accumulate in the brain and disrupt cellular function

ubiquitin

A small protein that tags misfolded proteins for degradation by the proteasome

Proteasome

a cellular machine that breaks down misfolded proteins

N-terminal

fragments of the Huntington protein that are produced when a protein is misfolded

Chaperone proteins

proteins that assist in refolding misfolded proteins

RHES

a protein highly expressed in the striatum that plays a role in dopaminergic signaling and protein modification

Sumoylation

a post-translational modification where SUMO proteins are attached to target proteins, influencing their stability, localization, and interactions

E1 Activation

activates SUMO

E2 Conjunction-Ubc9

transfer SUMO to target proteins

E3 Ligase

ensures specificity by guiding SUMO to target proteins correctly

Degradation

The breakdown of protein

Chorea

dance-like involuntary movements

Bradykinesia

slowness of movement

Dystonia

sustained muscle movement

Alzheimer’s disease

a degenerative brain disorder characterized by progressive cognitive decline, including memory less, impaired judgement and language difficulties

Extracellular Amyloid plaques

dense deposits of Beta-amyloid protein the accumulate outside neurons, disrupting communication.

Intercellular Neurofibrillary Tangles

structures composed of the Tau protein found inside neurons, which become hyperphosphorylated, leading to cellular dysfunction and death.

Amyloid Plaques

Another term for extracellular amyloid, referring to the same dense deposits of Beta-amyloid proteins

Beta-amyloid

a protein derived from that amyloid precursor protein (APP) , which is cleaved by Beta-secretase and Gamma-secretase, forming plaques

Hyperphosphorylated

a state where proteins, such as Tau in Alzheimer’s disease, have an excessive number of phosphate groups attached, leading to abnormal function and aggregation into tangles

Tau proteins

a protein that normally stabilizes the cell’s internal skeleton, but in AD, it becomes hyperphosphorylated and forms twisted filaments, disrupting cellular function and leading to cell death.

APoE Gene

A gene on chromosome 19 that influences beta-amyloid clearance and deposition

APP gene

A gene on chromosome 21 that can lead to excessive Beta-amyloid production, contributing to plaque formation,

Parkinson’s disease (PD)

a neurodegenerative disorder characterized by the degradation of dopamine-producing neurons in the substantia nigra, a critical part of basal ganglia responsible for regulating smooth and coordinated movements

Substantia Nigra

a part of the brain located in the basal ganglia that produces dopamine and play a key role in coordinating smooth movements.

Dopamine

a neurotransmitter that regulates smooth and coordinated muscle movements, its loss in the basal ganglia is a hallmark of Parkinson’s disease

Toxic gain of function

a genetic mechanism in Parkinson’s disease where mutations on chromosome 4 lead to the accumulation of alpha-synuclein, a protein that forms Lewy bodies and contributes to neuronal damage

Alpha-Synuclein

a protein that accumulates abnormally in Parkinson’s disease, forming Lewy bodies that contribute to neuronal death

Lewy bodies

abnormal protein aggregates composed of alpha-synuclein, found in the brains of individuals with Parkinson’s disease, leading to neuronal damage

Toxic Loss of Function

a genetic mutation in Parkinson’s disease involving mutations on chromosome 6 that affect the Parkin protein, impairing its ability to tag and remove damaged proteins

Parkin Protein

a protein that helps tag and remove damaged proteins in neurons; its dysfunction due to genetic mutations results in the accumulation of dysfunctional proteins and contributes to neuronal damage.

Brain tumors

abnormal cell masses that grow uncontrollably, disrupting normal brain function.

Malignant tumors

cancerous tumors that are aggressive, invasive, grow rapidly, and spread to other areas (ex:gliomas)

Benign tumors

non-cancerous that grow slowly, are generally confined to one area, and are easier to treat.

Encapsulated tumors

Tumors with a distinct border, making them easier to remove

Infiltrating tumors

tumors that spread into healthy tissue, making them harder to treat and more destructive

Metastasis

the spread of cancer cells from original tumor to other parts of the body, often affecting the lungs and complicating treatment

Seizure disorder

characterized by sudden, excessive electrical activity in the brain. They are classified into partial and generalized types

Partial seizures

seizures tat originate in specific brain area, causing change in consciousness but no loss of awareness

Complex partial seizures

a type of partial seizure resulting in of consciousness

generalized seizures

seizures that involve the entire brain area

Tonic-clonic seizures (grand mal)

the most severe type of of generalized seizure, involving muscle contractions and violent jerking