Chapter 6

Neural Plate
Is a thickened region of the ectodermal layer that gives rise to the neural tube
Neural Tube
A structure in the early stage of brain development from which the brain and spinal cord develop
Neural Stem Cell
Is a self-renewing, multipotential cell that gives rise to any of the different types of neuron and glia in the nervous system
Ventricular Zone
The lining of neural stem cells surrounding the ventricles in adults
Progenitor cell
Is the precursor cell derived from a stem cell and it migraes and produces a neuron or a glial cell
A product of a progenitor cell that gives rise to any of the different types of neurons
A product of a progenitor cell that gives rise to different types of glial cells
Neurotropic Factor
Is a chemical compound that acts to support growth and differentiation in the dev eloping neurons and may act to keep certain neurons alive in adulthood
Radial Glial Cell
Is a path-making cell that a migating neuron follows to its appropriate destination
Growth Cone
Is the growing tip of an axon
A process at the end of a developing axon that reaches out to search for a potential target or to sample th intercellular environment
Cell-Adhesion Molecule (CAM)
Ia a chemical to which specific cells can aadhere, thus aiding in migation
Tropic Molecule
A signaling molcule that attracts or repels growth cones
Is the only class of tropic molecules yet isolated
Neural Darwinism
A hypothesis at the processes of cell death and synptic pruning are, like natural selection in species, the out come of competition among neurons for connections and metabolic resourses in a natural environment
A cell death that is genetically programmed
Chemoaffinity Hypothesis
A proposal that neurons or teir axons and dendrites are drown toward a signaling chemical that indicates the correct pathway
Is a condition in which vision in one eye is reduced as a result of the two eyes to point in the same direction
Critical Period
A developmental window during which some event has a long-lasting influence on the brain and is often refered to as a sensitve period
A process that predisposes an animal to form an attachment to objects or animals at a critical period in development
A process by which exposure to androgens ( male hormones) alters the brain, rendering it male-like
Is a failure of the forebrain to devlope