Brain Development (CH.7)

ectoderm
Click the card to flip 👆
1 / 20
Terms in this set (20)
ectoderm
the outermost layer of the embryo which forms during gastrulation- it then becomes the nervous system
transcription factors
orchestrates development through assisting in gene expression that allows for segmentation and creation of tissue systems and cell types (body layout)
homeotic proteins
the transcription factors involved in determining the body layout
what is the gastrulation process?
primary germ layers (endoderm, mesoderm, ectoderm) are formed and organized in their proper locations
endoderm
the most internal germ layer- forms the lining of the gut and other internal organs
ectoderm
the most exterior layer- forms the skin, brain, and nervous system
mesoderm
middle germ layer- forms muscle, skeletal system, and circulatory system
what are the 6 stages of development?
1. neurogenesis
2. cell migration
3. differentiation
4. synaptogensis
5. neuronal cell death
6. synaptic rearrangement
neurogenesis
1st stage of development: cells on the inner side of neural tube (ventricular zone) undergo massive cell division- cells in the VZ provide the source from which all neurons and glial cells are derived
*cell-cell interactions determines what kind of cell is born
cell migration
2nd stage of development: refers to the movement of the newly formed neurons and glia to their eventual locations
-neural adhesion molecules (NCAMs) are chemicals that guide cells and growing axons to their appropriate target
cell differentiation3rd stage of development: process of cells adopting the features characteristic of the cell type for the particular brain region -neurons differ in their shape and chemical component depending on their location in the brainsynaptogenesis4th stage of development: refers to formation of the synapses between neurons during brain development -occurs throughout life as neurons are constantly forming new connectionsneuronal cell death5th stage of development: occurs throughout nervous system during development -occurs during apoptosissynaptic rearrangement6th stage of development: many early synapses are retracted and others are added during this stagedown syndrometrisomy 21- a genetic condition caused by the presence of an extra copy of chromosome 21 -results in impairment of cognitive ability, physical growth, and facial abnormalities -it demonstrates that genes/DNA are not passed on faithfullymendelian inheritancea set of tenets relating to fundamental principles of hereditary transmission of characteristics (genes) from parent organismsfragile x syndromesex-linked chromosomal abnormality characterized by trinucleotide (>200) repeats on the x chromosome -failure of expression of FMR1 gene, leading to neural defects (over-abundance of spine synapses in cortex) -results in mild-severe cognitive impairmentsphenylketonuria (PKU)metabolic genetic disorder resulting from inability to metabolize the amino acid phenylanine, leading to buildup phenylketones, resulting in neural damage and moderate-severe intellectual disabilityepigeneticsthe study of changes in phenotype/gene expression NOT caused by actual changes in DNA sequencewhat are the 2 ways epigenetics occurs?1. DNA methylation (chemical modification of parts of the genome) 2. Histone modification (alteration of histone proteins)