Flores - Vulnerability in Adolescence

Question 1

To which stress are adolescents particularly responsive? Why?

Answer 1

Social stress -> psychosocial growth

Question 2

When does social behaviour peak in rodents?

Answer 2

Adolescence

Question 3

To which characteristic behaviour is social defeat stress during adolescence leading to in adulthood? With which test is it evaluated in rodents?

Answer 3

Impulse control deficits -> commission errors in go/no-go task (going for reward when no-go trial)

Question 4

True or false: the go/no-go task is used both in humans and animals.

Answer 4

True

Question 5

Which test can be used to determine whether adolescent mice are more sensitive to the addictive potential of drugs of abuse?

Answer 5

CPP

Question 6

How does adult vs. adolescent exposure to AMPH influence performance on the go/no-go task? When in adolescence is the influence the strongest?

Answer 6

Adult = no diff.
Adolescence = more impulsive
Early adolescence

Question 7

True or false: Females do not show impulse control deficits following AMPH exposure in adolescence.

Answer 7

True

Question 8

What could explain over impulsivity in adolescence?

Answer 8

PFC still developing

Question 9

What synaptic process is still vigorously ongoing during adolescence?

Answer 9

Formation of new spines in the cortex in humans

Question 10

Why glial process is particularly protracted in the human prefrontal cortex?

Answer 10

Myelination

Question 11

True or false: density of dopamine fibers in the PFC continues to increase until adulthood. Why?

Answer 11

True: DA axons are still growing to PFC during adolescence

Question 12

What is Netrin-1? What receptors attract vs. repel netrin-1?

Answer 12

Bifunctional axonal guidance cue
Attract: DCC
Repel: UNC-5

Question 13

How are neurons from the VTA discriminated between mesocortical and mesolimbic axonal guidance?

Answer 13

VTA neurons going for PFC = no DCC receptor
VTA neurons going for NAc = express DCC

Both PFC and NAc contain Netrin-1 protein

Question 14

Genetic variation in DCC and Netrin-1 is associated with which health outcomes?

Answer 14

psychiatric disorders of adolescent onset

Question 15

What is the impact of amphetamine use on DCC receptors in DA neurons during adolescence? On axonal patterning of mesolimbic DA neurons going to PFC?

Answer 15

Downregulation

Ectopic growth

Question 16

How do microRNAs repress protein expression?

Answer 16

mRNA degradation
Translational repression

Question 17

Which microRNA is known to repress DCC expression?

Answer 17

miR-218

Question 18

How can microRNA levels be assessed?

Answer 18

Blood sample

Question 19

Are miR-218 found in DA neurons?

Answer 19

Yes

Question 20

What could be the clinical utility of miR-218?

Answer 20

Circulating miR-218 levels in adolescence predict vulnerability to stress in adulthood

Question 21

What is the impact of social stress during adolescence on miR-218 levels?

Answer 21

Overmature levels (adult-like)