Task 3 Brainy Methods Flashcards
- Neurolation
Formation of the neural tube(prenatal)
- Neurogenesis
the mitotic division of nonneuronal cells to produce neurons (prenatal)
• Neurons begin as a single layer in the inside of the neural tube, they divide by a process called mitosis
• Ventricular zone: A region lining in the cerebral ventricles that displays mitosis, providing neurons early in development and glial cells through life
o All glia and neuron cells are derived from cells that originate from the ventricular zone
• Cell-cell interactions: The general process during development in which, one cell affects the differentiation of other, usually neighbouring cells
- Cell migration
the movements of the cells to establish distinct nerve cell populations (brain nuclei, layers of the cerebral cortex, and so on) (prenatal)
• Cell migration: The movement of cells from site of origin to final location
• Radial glia cells: Glia cells that from early and provide orientation, creeping along them, for the migrated cells
• Cell adhesion molecule (CAM): A protein found on the surface of a cell migration and/or axonal pathfinding
- Diffferentiation
- Differentiation: the transformation of precursor cells into distinctive types of neurons and glia cells (Postnatal)
• The cell begins to use or express particular genes, which means that the transcribes the specific proteins it needs, shapes cell into distinctive forms and gives rise to functions of the region
• Cell autonomous differentiation: presumably only genes within that cell are directing events, and not influenced from the outside
• Induction: The process by which one set of cells influences the fate of neighbouring cells, usually by secreting a chemical factor that changes gene expression in the target cell
• Regulation: the developing animals compensates for missing or injured cells
o Stem cells: Cells that can adapt everywhere
- Synaptogenesis
the establishment of synaptic connections, as axons and dendrites grow
• Growth cones: the growing tip of an axons or a dendrite
• Filopodia: Very fine, tubular outgrowths from the growth cone, they contract somewhere and pull the growth cone in this particular direction
• Chemoattractant: Compounds that attract particular classes of axonal growth cones
• Chemorepellents: Compounds that repel particular classes of axonal growth cones
o Important for crossing the body site or staying on the wanted site
- Neuronal cell death
the selective death of many nerve cells
• Number of Neurons that die during early development is quite large
• Death genes: A gene that is expressed only when a cell becomes committed to natural cell death (apoptosis)
- synapse rearrangement
the loss of some synapses and development of others, to refine synaptic connections
• Takes place after period of cell death
• Thinning of grey matter
- Myelination
its prenatal but continues after birth
Week after fertilization
Embryo shows the beginning of all tissues, that consists of three cell layers: mesoderm, ectoderm and endoderm.
Ectoderm – Outer cellular layer of developing embryo, that gives rise to the skin and nervous system.
20 days after fertilization
Cell layers thicken and grow into flat oval plate, creating a neural groove.
22 days after fertilization
Ridges of neural groove come together to form neural tube, a structure with subdivisions that correspond to the future forebrain, midbrain and hindbrain.
24 days after fertilization
Interior of neural tube becomes fluid-filled cerebral ventricles of brain, central canal of spinal cord and passages connecting them.
8th week
Embryo shows beginnings of most body organs. By this time, head is half the total size of embryo
10th week onwards
From this week, we start calling it a fetus. Until week 41 the fetus will undergo changes, especially when it comes to the emergence of gyri and sulci, which is done gradually
Grey matter development
loss during the childhood and adolescence reflects a sculpting process of the immature brain into the fully working mature brain
o Reflects the ongoing neuronal regressive events, such as pruning and elimination of connections
o Prefrontal cortex: the neuron loss is a hormone dependent process
White matter development
white matter volume increases in roughly linear pattern until young adulthood
o Reflect on ongoing myelination of axons
o Connections are being fine-tuned with the elimination of an overabundance of synapses and strengthening of relevant connections with development and experience
o Hormone independent (independent of puberty)
Cognitive pathway development
supports reasoned, appropriate & deliberate decisions
o Prefrontal cortex
o Linear development extending into adulthood
o Deliberative-processing-system: not yet mature enough to compensate for heightened affective response -> creates period of vulnerability to affective inputs that encourage risky & reckless behaviour
Affective pathway development
encourages affective, impulsive & reward focused decisions
o Limbic system: governs reward sensitivity and sensation seeking
o Inverted U shaped pattern of development, most dramatic during first part of adolescence
o Active-processing-system: in state of hypersensitivity due to asynchrony in structural and functional maturation of the brain
Order of cortical area development
- Frist primary functions such as motor and sensory systems
- Temporal and parietal association cortices associated with basic language skills and spatial attention
- Higher order association areas, such as the prefrontal and lateral temporal cortices, which integrate primary sensorimotor processes and modulate basic attention and language processing, seem to mature last
Interview
Children answer questions asked either in person or in a questionnaire
Naturalistic Observation
Activities of children in everyday settings are observed
Structured Observation
Children presented to prearranged tasks in lab-setting
Correlational Design
Comparison of different (groups of) children and their scores on different variables
Experimental design
Random assignment of children to groups & experimental control of procedure
Cross-sectional design
Children of different ages are studied at a single time
Longitudinal design
Children are examined repeatedly over a prolonged period of time
Sequential design
Combines longitudinal and cross-sectional approaches
Micro-genetic design
Children are observed intensively over a relatively short period of time while a change is occurring
Chemoaffinity hypothesis
The notion that each cell has a chemical identity that directs it to synapses on the proper target cell during development
