How does the nervous system develop and adapt?

Question 1

testosterone

Answer 1

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

Question 1

tropic molecule

Answer 1

Signaling molecule that attracts or repels growth cones.

Question 2

filopod (pl. filopodia)

Answer 2

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

Question 2

gene (DNA) methylation

Answer 2

Process in which a methyl group attaches to the DNA sequence resulting in the suppression of gene expression.

Question 3

growth cone

Answer 3

Growing tip of an axon.

Question 4

subventricular zone

Answer 4

Lining of neural stem cells surrounding the ventricles in adults.

Question 5

glioblast

Answer 5

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

Question 5

netrin

Answer 5

Member of the only class of tropic molecules yet isolated.

Question 7

apoptosis

Answer 7

Cell death that is genetically programmed.

Question 7

neural Darwinism

Answer 7

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 8

anencephaly

Answer 8

Failure of the forebrain to develop.

Question 8

chemoaffinity hypothesis

Answer 8

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

Question 10

estrogens

Answer 10

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

Question 12

amblyopia

Answer 12

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

Question 13

neurotrophic factor

Answer 13

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

Question 14

imprinting

Answer 14

Process that predisposes an animal to form an attachment to objects or animals at a critical period in development.

Question 15

autism spectrum disorder (ASD)

Answer 15

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 16

neural plate

Answer 16

Thickened region of the ectodermal layer that gives rise to the neural tube.

Question 18

androgen

Answer 18

Class of hormones that stimulates or controls masculine characteristics.

Question 19

masculinization

Answer 19

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

Question 20

progenitor cell

Answer 20

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

Question 21

neural stem cell

Answer 21

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

Question 22

neuroblast

Answer 22

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

Question 23

radial glial cell

Answer 23

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

Question 25

critical period

Answer 25

Developmental ‘window’ during which some event has a long-lasting influence on the brain; often referred to as a sensitive period.

Question 26

sudden infant death syndrome (SIDS)

Answer 26

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

Question 27

neural tube

Answer 27

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

Question 28

growth spurt

Answer 28

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

Question 29

cell-adhesion molecule (CAM)

Answer 29

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