CNS development

Question 1

human brain development begins when

Answer 1

3rd week post conception

Question 2

intrauterine environment 3 influences

Answer 2

maternal health and disease (PKU)
insults - episodic/continuous (cytolomegalovirus, infection)
placental function and feotal nutrition

Question 3

extrauterine environment - 3 influences

Answer 3

physical factors (nutrition, toxins)
emotional/social factors (neglect, lack of stim)
exposure - drugs, alcohol

Question 4

embryonic period from conception to __, foetal development is from __ to __, then __ __ development begins

Answer 4

week 9
week 9 to 40/42
post natal

Question 5

the embryo begins as 2 layers, the __ and __. cells migrate though the __ streak then rostral-__ migration begins. This is determined by __ __

Answer 5

epiblast + hypoblast

primitive streak

rosttral-caudal

nodal signalling

Question 6

__ results in the development of a 3 layered embryo.

Ectoderm - __ __ __ and neural tissue

_____ - muscle, bone, cartilage and ___ system

endoderm - __ aand resp syste,

Answer 6

gastrulation

skin hair nails

mesoderm, vascular

gut

Question 7

the ___ __ is the first well defined neural strucute. the neural __ line the inside of the neural tube - termed the __ zone.

the hollow centre of the tube becomes the ___ system and central channel of the spinal cord.

the anterior/rostral tube will become the ___, and the caudal tube will become the ___ __

Answer 7

neural tube

progenitors

ventricular

ventricular system

rostral = brain

caudal = spinal cord

Question 8

as mentioned brain development begins at 3wks, the primary brain vesciles can be divided into the ___ (forebrain), mesencephalon (___), and ___ (hindbrain)

Answer 8

prosencephalon - forebrain

mesencephalon - midbrain

rhombencephalon - hindbrain

Question 9

by week 5, how many vesciles are there

Answer 9

5 (secondary vesciles - telencephalon, dicencephalon, mesencephalon, metencephalon, myelencephalon)

Question 10

what sets the stage for latter neural development

Answer 10

neural patterning

Question 11

Emx2 and Pax6 are 2 signalling molecules between the anterior/rostral and posterior/caudal. When there is high conc. of Pax6 (and low Emx2), this induces progenitor cell to differentiate into ___ neurons. When there is low conc. Pax6 (and high…) this induces __ __ neurons

Answer 11

motor

visual cortical

Question 12

brain is initially smooth (lissencephalic) then develops the folded appearance. Name given for this pattern q

Answer 12

sulcal and gyral

Question 13

the development of gyri and sulci is required to accomodate the __ __ populations

Answer 13

proliferating neuronal

Question 14

initially, neuronal progenitor cells in the ventricular zone divide ___ ( 2 prog. cells) (days 25-42) Assymetrical division then follows, producing one progenitro cell and one __. at this point can the cells divide further?

Answer 14

symmetrically

neuron

no - post mitotic

Question 15

progenitor cells remain in the ventricular zone nad continue to divide, producing more cells, what do the neurons do?

Answer 15

migrate to develop the neocortex

Question 16

neocortex

Answer 16

cortex involved in sight and hearing

Question 17

once nuerons reach their target cortical regions they e velop processes which allow them to communicate and transmit info between neurons. Axons and dendrites, what does each do ? `

Answer 17

axons - transmit signals from neurons (guidance molecules determine path, synapses develop when connected with another neuron)

dendrites - gather info and transmit to neurons

Question 18

muliple dendrites form __ around the neuron

Answer 18

arbors

Question 19

postnatal brain developkent can be divided into __ ___ and __, and __

Answer 19

postnatal proliferation and migration

myelination

Question 20

the limited neuronal proliferation from ventricular zone generates the __ bulb, dentate gyrus of the __

Answer 20

olfactory

hippocamous

astrocytes

Question 21

which cell creates the myelin seath

Answer 21

OPCs

Question 22

effect of estrogen on teenage females

effect of androgens on teenage males

Answer 22

more prone to stress

more resilient to stressv

(rising gonadal hormone con.c leads to physical maturation of brain, its full of steroid hormones)

Question 23

insults in the first few weeks of life are usualy not compatible with life. list 5 things his will affect

Answer 23

neural tube formation 
brain vesicles 
migration disturbances 
inherited defects 
malnutrition

Question 24

holoprosencephaly is the failure of __ __ to form. the degree of severity spans from normal, to lobar, semi__ and __

Answer 24

2 hemispheres
semilobar

alobar

Question 25

PLP1 encodes a transmembrane proteolipi protein in the prodminant mylin protein, present in CNS.
function of PLP1 gene
which chromosome is it located

Answer 25

myelin sheath health (compaction, stabilisation, maintenance)
oligodendrocyte development
axondal survival

x chromosome

Question 26

mutation in PLP1 causes spectrum of disorders, which is th most severe, 3 findings which make up its presentation, what does it progress to

Answer 26

pelizaeus-merzbacher

nystagmus (invol. eye movement)
hypotonia (low muscle tone)
cognitive impairement

severe spasticity and ataxia (lack of voluntary motor movements)

Question 27

malnutrition impacts the brains __ and __, the myelination, leads to a lack of energy and deprivation, and progrsses postnatally into lack of __ and __

Answer 27

growth and volume

stimulation and experiences

(biggest silent disaster)
some recovery possible