Neurodevelopment and ethological animal models Flashcards
Within the first 2 weeks after fertilization, the cells of the embryonic disc differentiate into:
Endoderm
Ectoderm
Endoderm becomes the
respiratory and digestive tract
Ectoderm becomes the
nervous system
3-4 weeks after conception, ectoderm forms primitive
Neural plate
~18 days, neural plate forms the
neural tube
Top of the neural tube forms 3 bulges which become:
- Prosencephalon (forebrain)
- Mesencephalon (midbrain)
- Rhombencephalon (hindbrain)
Prosencephalon
(forebrain)
Mesencephalon
(midbrain)
Rhombencephalon
(hindbrain)
Remainder of the neural tube becomes the
spinal cord
remain outside the neural tube as it folds,
Neuroblasts (young neurons)
Neuroblasts (young neurons) remain outside the neural tube as it folds,
becoming the
neural crest
Neural crest gives rise to the peripheral
Autonomic nervous system
Steps of neuronal development (6)
- Induction
- Proliferation
- Migration
- Differentiation
- Circuit formation
- Cell Death
Process that allows some parts of the ectoderm of the neural disc to become transformed into the neural plate
Induction
Crucial initiating step is interaction between the ectoderm and the mesoderm
Induction
If top (rostral) end of neural tube doesn’t close, child is born without
cortex (anencephalic)
If caudal end of neural tube doesn’t close,
general motor impairments, but cognition spared
The cell division throughout which the few cells making up the neural plate and neural tube multiply to become the billions of cells of a complete brain
Proliferation
When does proliferation begin?
After the neural tube closes
How many phases does proliferation occur in?
2
Movement of newly formed cells from the region in which they proliferated to their final destination in the brain
Migration
In migration, cells move back and forth between the ______ and _______ zones until they stop in the _______ or ______ zone
ventricular and marginal zones
stop in the intermediate or subventricular zone
In Migration, cells terminating in the _____ zone continue to proliferate
subventricular zone (between intermediate and ventricular zone)
Cell bodies of radial glial cells remain in the ____ zone, while cell processes radiate out to the surface are used as scaffolding for neurons to traverse during migration
subventricular zone
Normal migration results in
deep layers of cortex formed first by oldest (earliest formed) neurons
Thalamic nuclei originate as well as cortical layers form as a result of…
Aggregation
Mutual adhesion of similar cells as a first step in the formation of fxl brain parts is part of…..
Aggregation
Process by which each neuron acquires its given size, shape, location, connections, and mode of transmitting messages (excitatory vs. inhibitory)
Differentiation
Apoptosis
programmed cell death (NOT necrosis)
Olfactory parts of the brain develop during (also includes hippocampus)
telencephalic refinement (second month)
provide a blueprint for vulnerability or resistence by altering fundamental developmental outcomes
Genes
participate in the process of tipping the developmental scales towards a better or poorer outcome
Environmental factors
How we study neurodevelopmental disorders…
Genes Cells Circuits Organs Gene x Environment Behavior
strong analogies to the
endophenotypes in the human disorder
Face validity
the same biological dysfunction that causes the disorder in humans (gene mutation/ circuit effects)
Construct validity
predictive response to treatments that reverse or prevent the disorder
Predictive validity
