Term
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Definition
| Chemical Affinity Hypothesis |
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Term
| There are over ______ neurons. |
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Definition
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Term
| What are the stages of brain development? |
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Definition
1. Induction of neural system
2. Proliferation
3. Migration
4. Aggregation
5. Differentiation
6. Synaptogenesis
7. Selective cell death
8. Functional validation |
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Term
| The neural plate begins to develop ________ before conception. |
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Definition
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Term
| The cells of the neural plate begin to form on the _________ which ultimately form the nervous system. |
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Definition
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Term
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Definition
| The groove that forms when the neural plate raises and forms bilateral ridges |
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Term
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Definition
| Develops when the neural groove fully encloses |
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Term
| The central canal and the ventricles |
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Definition
| These are derived from the space within the neural tube |
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Term
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Definition
| The production of new cells |
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Term
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Definition
| The neurons to develop first are the _________. |
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Term
| In what order would the retinal ganglion cells, rods and cones and bipolar cells develop during the proliferation stage? |
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Definition
| The retinal ganglion cells will be produced first followed by bipolar and then rods and cones. |
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Term
| The neurons that are born first tend to occupy the ____________ of the cortex, the later born migrate past those to occupy the _________________. |
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Definition
| inner most layers , more superficial layers |
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Term
| How many layers are in the cortex? |
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Definition
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Term
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Definition
| Pertains to the movement of the cells toward their eventual destinations |
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Term
| How does a migrating Neuroblast know where to go? |
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Definition
| Some are guided by radial glia cells and other use chemical guidance systems |
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Term
| How do radial glia cells help Neuroblasts migrate? |
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Definition
| It acts as a scaffolding apparatus. The Neuroblast wraps around the glia and move along it to a particular region. They are only useful for moving short distances. |
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Term
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Definition
| Fitting in with other cells |
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Term
| How does Aggregation occur? |
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Definition
| Different cells are able to recognize their mates, those who will become similar to them by means of a protein or chemical recognition. |
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Term
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Definition
| As the cell is migrating they are developing extensions (axons, dendrites, etc.) the growth cones that appear at the end of the extensions are a type of living thing that pushes other things out of the way and allowing it to move. It is also pulling the extension forward. |
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Term
| What effect do chemicals have on growth cones? |
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Definition
| The growth cone will incorporate nutrients that it encounters. It is chemical dependent. When it comes into contact with chemicals that it does not like it will pull back and change direction. When it finds a chemical that it like it will follow it, leading the neuron to a certain place. |
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Term
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Definition
| The process of synapse formation and the developing neurons now interact with others to determine which acceptable partners are and which are not |
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Term
| Chemical Affinity Hypothesis |
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Definition
| neurons develop their own particular chemical identity |
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Term
| The Optic Tectum is the __________________ in frogs. |
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Definition
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Term
| During Sperry's work with frogs the vision remained normal after cutting the optic tectum, what was his reasoning? |
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Definition
Sperry proposed that what happens is the fibers that are similar to each other will chemically recognize their other half and reform. For example
fiber A finds the other fiber A. The B fiber will find the B fiber…etc. |
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Term
| What was the counter proposal to Sperry's theory on why frogs maintain after Optic Tectum regeneration? |
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Definition
| The counter hypothesis states that the fibers do not necessarily reconnect with the fibers that were originally connected to. Fiber A can connect with fiber C and fiber B can connect with fiber D. Our mind in turn learns new ways of viewing the world in order to support this change. (an example is the video of the upside down glasses). |
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Term
| TOPDV (topography dorsal ventral) |
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Definition
protein that varies across the retina of the frog
This change in gradient could cause the chemical recognition. Neurons with a high concentration look for others that are of high concentration and low look for low. |
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Term
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Definition
| a. When a neuron fails to make an appropriate connection with another neuron by a certain age the neuron will kill itself (by apoptosis- a suicide program) |
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Term
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Definition
looked at muscular junctions:
- saw that they release and produce a chemical substance known as a nerve growth factor (NGF)
- This chemical promotes the survival and growth of incoming axons |
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Term
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Definition
- works in the brain to prevent apoptosis
- help to promote axonal branching to fill vacated spaces due to the loss of neurons |
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Term
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Definition
| Once you establish a circuit you have to use it, if you fail to it will be eliminated |
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Term
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Definition
if you tweak a whisker on a mouse the whisker is connected to a certain barrel shaped area on the somatosensory cortex
- He eliminated a number of whiskers after birth
- the barrels were no longer being stimulated so they disappeared
- The barrels connected for the other whiskers expand to fill the gap |
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Term
| Rosenzweig, Bennett, Krech, Diamond |
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Definition
Primary finding was that the development of the cortex
- The more stimulation the thicker the cortex and the heavier it will be. The dendrites (many more spines in stimulated rats) are most particularly affected. This allows for more connections between neurons, they were smarter
- E vs. I = weight was 5% heavier
- E vs. S = 2% heavier
- Impoverished – they lose neurons due to lack of stimulation |
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