Neurodevelopment Flashcards
what is the Germinal stage?
when the nuclei of the egg and sperm fuse and form a zygote. At 12 hours cleavage occurs - zygote divides to form cluster of cells called morula
what is morula?
a cluster of cells formed from the zygote undergoing cell division. occurs in the germinal stage
what is a blastocyst?
the morula continues to divide and forms a blastocyst
when does the embryonic stage begin?
once implantation in the uterus occurs
what is gastrulation?
an early phase of the embryonic stage
what are the 3 layers the embryonic disc
?
ectoderm, mesoderm, endoderm
what does the ectoderm eventually become, and how?
the nervous system, by folding in on itself to form the neural tube
what are the 6 stages of brain development in order?
cell birth, cell migration, cell differentiation & maturation, synaptogenesis and synaptic pruning, cell death, myelination
how do cells migrate out of the ventricular zone?
chemical signals - immonuglobulins & cytokins
physical support - radial glia
what happens if cells fail to migrate the ventricular zone?
there may be serious effects eg. dyslexia and epilepsy
how do cells differentiate?
they express different genes through the growth of axons and dendrites which give them a distinctive shape
what are the two types of dendritic development?
dendritic arborization (branching), and growth of dendritic spines
what is the growth cone?
the growing end of the axon
what are filopodia?
thin extensions that growth cones develop
what are the names of the chemicals from target sites that attract the growth cones?
cell adhesion molecules (CAM)
tropic molecules
what is synaptic pruning?
where the synapses that are not used are eliminated and active synapses are maintained and strengthened
what is synaptic rearrangement?
where synapses take over other synapses, can happen at any stage of life and occurs as a result of experience
what are the two types of cell death and what are they?
apoptosis - programmed cell death, a natural process and little damage is caused
necrosis - a result of injury, cell bursts and causes damage to surrounding neurons
what is apoptosis?
programmed cell death, it is a natural process and causes little to no damage to surrounding neurons
what is necrosis?
cell death as a result of injury, the cell ‘bursts’ and causes alot of damage to surrounding neurons
what is myelination?
a process where glia form the fatty sheath that covers the axons of neurons
what does the myelin sheath do?
speeds up transmission of neural impulses
what is collateral sprouting?
sprouting of non-damaged axons to fill vacant synapses, is a part of recovery after injury
what is brain plasticity
it’s ability to adapt as a result of experience and injury
what did Burton 2002 find?
that the occipital cortex in blind people was activated when asked to feel braille
what is a critical period?
a period during which the brain is most sensitive to a specific experience
what is epigenetics?
the study of the interaction of gene expression and the environment
