cell death

Question 1

what percentage of cell death occurs in the brain

Answer 1

20-80% depending on region

Question 2

what are the types of cell death

Answer 2

apoptosis, autophagy, necrosis

Question 3

autophagy description

Answer 3

cells degrade themselves. detected by the presence of autophagosomes prior to DNA damage

Question 4

necrosis description

Answer 4

mostly found after injury .mitochondria stop functioning and cell bursts

Question 5

apoptosis description

Answer 5

programmed cell death.
condensation of chromatin,
aggregation of crescent shaped figures at the nuclear membrane (pyknosis), fragmentatoin of DNA rougly 180 bp. ultimately cells are phagocytoses by macrophages

Question 6

what is TUNEL staining and what used for

Answer 6

terminal transferase UTP Nick end labeling. labels the nicked areas of DNA using a dNTP labeled with biotin and strepavidin

Question 7

apoptosis vs autophagy

Answer 7

autophagic vesicles form throughout the cell and form uniform cellular structures that are filled with vesicular structures. apoptosis is characterized by nuclear condensation

Question 8

necrosis vs apoptosis

Answer 8

cells burst open.

Question 9

which cells undergo programmed cell death

Answer 9

progenitors, differentiated neurons, and glia.

Question 10

what percent of progenitors PCD

Answer 10

profound 10-50%

Question 11

what percent of progenitors neurons

Answer 11

20-80 profound

Question 12

what percent of progenitors glia

Answer 12

profound 50% of all oligodendrocytes.

Question 13

what regulates neuronal PCD

Answer 13

trophic support

Question 14

when is the most cell death

Answer 14

during synaptogenesis and progenitors

Question 15

what else controls survival

Answer 15

tissue targets (adding a limb causes increased numbers of neuronal survival)

Question 16

examples of neurotropins

Answer 16

NGF, BDNF, NT-3

Question 17

TrkA cell types

Answer 17

DRG(70), SCG (95%), trigeminal (70), basal forebrain

Question 18

TrkC cell types

Answer 18

DRG (20), trigeminal (20), cochlear (50%), vestibular(15%)

Question 19

TrkB cell types

Answer 19

DRG 30, trigeminal 60, cochlear 15 vestibular 60 nodose 90 basal forebrain and cerebellum

Question 20

what is the receptor for NGF

Answer 20

TrKA

Question 21

receptor for BDNF

Answer 21

TrkB

Question 22

how do neurotropins signal to the soma

Answer 22

they bind in the periphery and are internalized, then trafficked to the soma.

Question 23

what does the P75 receptor do and why is it significant

Answer 23

it initiates cell death when signaled. it is signaled by pro nerve factors

Question 24

is cell death active or passive

Answer 24

it is active and requires protein synthesis.

Question 25

what are the intracellular cell survival pathways

Answer 25

pi3k-akt pathways, MAPK, JNK, CDK

Question 26

how do the caspases mediate cell death?

Answer 26

macromolecular degeneration and DNA degradation.

Question 27

what else mediates neuronal survival

Answer 27

depolarization and calcium signaling