lecture 5

Question 1

find central nervous system info in textbook

Answer 1

textbook

Question 2

when do changes in neural development happen?

Answer 2

an event can influence events that will follow, but not those that precede it

Question 3

what is the difference between absolute and relative timing?

Answer 3

absolute: days since conception
relative: precedes or follows eye opening

Question 4

If A comes before B, can A influence B?

Answer 4

yes, but B cannot influence A

Question 5

where do changes in neural development happen and which structures are affected?

Answer 5

developmental subdivisions along the length, radius, & circumference of the neural tube precede & presage functional subdivisions

Question 6

what happens to structures of sperm during changes in neural development?

Answer 6

the tail becomes the spinal cord as the head becomes the brain, vertebrae differ in top/bottom dimensions, and the radius determines internal organization of segments

Question 7

what is spina bifida?

Answer 7

failure in closure of bottom neural tube (spinal cord)

Question 8

what problems do people with anencephaly or encephalocele have?

Answer 8

failure in closure of top (brain)

Question 9

what happens if the cell fails to develop? (cell proliferation)

Answer 9

• no proliferation (production) of
  neurons beyond prenatal period (sort of)
• neuroblasts produce a definite and limited number of cells
• produce specific types of cells - contain subpopulations (lineages)
• each precursor cell produces a limited number of cells
• signal to stop proliferating is self-contained (not determined by age or position)

Question 10

what happens if a cell fails to migrate?

Answer 10

• passive displacement evolutionarily “older” areas of brain): existing cells are pushed outward as new cells are produced
• active migration (“newer” areas of the brain): cells actively move from the point of production to eventual destination

Question 11

what is the difference between covergent and divergent connections to cells?

Answer 11

covergent: many to one
divergent: one to many

Question 12

explain the frontal cortex

Answer 12

• largest area of cortex human brain
• largest proportional increase in seize over the course of evolution
• longer to reach maturity than any other area of the brain (puberty)

Question 13

explain the prefrontal cortex

Answer 13

• subserves “highest” cognitive abilities

- reasoning, problem solving, intentional, conscious behaviours

Question 14

explain intentionality

Answer 14

• planning, goal-directed, means-end behaviour

- acting on one object as a mean to the goal of acting on another object

Question 15

what is Phenylketonuria (PKU)?

Answer 15

a recessive disorders causing an inability to metabolize phenylalanine (amino acid in milk, eggs, bread, fish)
- phenylalanine (Phe) builds up in blood and interferes with brain cell development.

Question 16

if the hypothesis of PKU studies states elevated levels of phenylalanine (Phe) interfere with development and functioning of prefrontal cortex (PFC), what does that mean?

Answer 16

• Phe competes with tyrosine for uptake by receptor in PFC
• tyrosine is needed to produce dopamine
• PFC relies on dopamine
• reduced dopamine impairs PFC development and functioning

Question 17

what does the PFC control?

Answer 17

planning, reasoning, problem solving, intentional conscious behaviours