Chapter 8

Question 1

neural plate

Answer 1

Primitive neural tissue that gives rise to the neural tube.

Question 2

neural tube

Answer 2

Structure in the early stage of brain development from which the brain and spinal cord develop.

Question 3

Zygote

Answer 3

Fertilization to 2 weeks

Question 4

Embryo

Answer 4

2 to 8 weeks

Question 5

Fetus

Answer 5

9 weeks to birth

Question 6

neural stem cell

Answer 6

Self-renewing multipotential cell that gives rise to any of the different types of neurons and glia in the nervous system.

Question 7

subventricular zone

Answer 7

Lining of neural stem cells surrounding the ventricles in adults.

Question 8

progenitor cell (precursor cell)

Answer 8

Derived from a stem cell; it migrates and produces a neuron or a glial cell.

Question 9

neuroblast

Answer 9

Product of a progenitor cell that gives rise to any of the different types of neurons.

Question 10

glioblast

Answer 10

Product of a progenitor cell that gives rise to different types of glial cells.

Question 11

neurotrophic factor

Answer 11

A chemical compound that supports growth and differentiation in developing neurons and may act to keep certain neurons alive in adulthood.

Question 12

Stages of Development

Answer 12

1. Cell birth (neurogenesis; gliogenesis)
2. Cell migration
3. Cell differentiation
4. Cell maturation (dendrite and axon growth)
5. Synaptogenesis (formation of synapses)
6. Cell death and synaptic pruning
7. Myelogenesis (formation of myelin)

Question 13

radial glial cell

Answer 13

Path-making cell that a migrating neuron follows to its appropriate destination.

Question 14

autism spectrum disorder (ASD)

Answer 14

Range of cognitive symptoms from mild to severe that characterize autism; severe symptoms include greatly impaired social interaction, a bizarre and narrow range of interests, marked abnormalities in language and communication, and fixed, repetitive movements.

Question 15

growth cone

Answer 15

Growing tip of an axon.

Question 16

filopod (pl. filopodia)

Answer 16

Process at the end of a developing axon that reaches out to search for a potential target or to sample the intercellular environment.

Question 17

cell adhesion molecule (CAM)

Answer 17

A chemical molecule to which specific cells can adhere, thus aiding in migration.

Question 18

tropic molecule

Answer 18

Signaling molecule that attracts or repels growth cones.

Question 19

netrin

Answer 19

Member of the only class of tropic molecules yet isolated.

Question 20

neural Darwinism

Answer 20

Hypothesis that the processes of cell death and synaptic pruning are, like natural selection in species, the outcome of competition among neurons for connections and metabolic resources in a neural environment.

Question 21

apoptosis

Answer 21

Genetically programmed cell death.

Question 22

dorsolateral prefrontal cortex (DLPFC)

Answer 22

Brodmann areas 9 and 46; makes reciprocal connections with posterior parietal cortex and the superior temporal sulcus; responsible for selecting behavior and movement with respect to temporal memory.

Question 23

growth spurt

Answer 23

Sporadic period of sudden growth that lasts for a finite time.

Question 24

chemoaffinity hypothesis

Answer 24

Proposal that neurons or their axons and dendrites are drawn toward a signaling chemical that indicates the correct pathway.

Question 25

amblyopia

Answer 25

Condition in which vision in one eye is reduced as a result of disuse; usually caused by a failure of the two eyes to look in the same direction.

Question 26

critical period

Answer 26

Developmental window during which some event has a long-lasting influence on the brain; also, sensitive period.

Question 27

imprinting

Answer 27

Formation of an attachment by an animal to one or more objects or animals at a critical period in development.

Question 28

testosterone

Answer 28

Sex hormone secreted by the testes and responsible for the distinguishing characteristics of the male.

Question 29

androgen

Answer 29

Class of hormones that stimulates or controls masculine characteristics.

Question 30

masculinization

Answer 30

Process by which exposure to androgens (male sex hormones) alters the brain, rendering it identifiably male.

Question 31

estrogens

Answer 31

Variety of sex hormones responsible for the distinguishing characteristics of the female.

Question 32

anencephaly

Answer 32

Failure of the forebrain to develop.

Question 33

sudden infant death syndrome (siDs)

Answer 33

Unexplained death while asleep of a seemingly healthy infant less than 1 year old.