Flashcards in Genetics and Brain Development Deck (161)
Neural tube disorder that causes the bottom of the spinal cord to not close
Embryonic brain regions of the hindbrain
Mesencephalon and myelencephalon
Where does myelination start and where does it lead to?
Occurs in the rostral direction starting with the spinal cord, then hindbrain, midbrain, and forebrain
What does blue light do in optogenetics?
Activates on opsin called channelrhodopsin to allow positive ions in the neuron for firing of the neuron
Examples of sex-linked characteristics?
Hemophilia and color blindness
Characteristics of the candidate gene approach
hypothesis driven, confirmatory, systematic scanning
What is neurogenesis?
Formation of neurons and glia from stem cells
How many mutations are in the average new born?
Around 130 new mutations with most having little to no effect
How are genes arranged?
Linearly on chromosomes
Fragile-X syndrome, phenylketonuria (PKU), down syndrome
When does plasticity occur?
Growth and development, learning: long term potentiation and enriched environments, following injury (limited), and possibly adult neurogenesis
What happens with synapses in people with schizophrenia and Alzheimer's?
Too few synapses in schizophrenia and normal in Alzheimer's until older age when there are far too few
What is cell migration?
Cells in the cerebral cortex arrive in an inside-out fashion
What does retroviral gene therapy do?
A virus enters a host cell and the virus inserts its DNA into the host's DNA. The cell makes virus genes and proteins as it reads its own DNA.
How many genes are in the human genome?
What happens during differentiation in the dorsal-ventral axis?
Neurons are distinguished between sensory and motor
Where are progenitor cells found?
The ventricular zone lining the neural tube
What is a genotype?
A person's 23 pairs of chromosomes
Example of a CNV
Huntington's disease. Too many copies of a gene, specifically too many CAG repeats.
Abnormalities in synaptogenesis and neurocognitive disorders
Schizophrenia has less connections. Autism has a lot of immature spines
How do growth cones form synapses?
Growth cones approach muscle fibers, they make contact, and synaptic vesicles accumulate in axon terminal and synaptic receptors cluster at point of contact
What has to be taken into account when assessing heritability?
What does a heritability value of 0 represent?
Genes play no role in phenotypical differences. Ex - environmental toxin exposure
What is plasticity?
They nervous systems ability to change
How many pairs of autosomes?
What is histone modification?
Epigenetics. DNA may unwrap or be stopped from unwrapping from the histone
What is a gene?
Segment of DNA that produces a single protein
What are alleles?
Different versions of a gene
What is the mesoderm?
Middle germ layer that becomes connective tissue such as ligaments, muscles, blood vessels, and urogenital system