Adolescence def
Phase of gradual transition between childhood and adulthood
Charactereistics of adolscence
· Heightened stress
· Drive for independence
. Increased salience of social and peer interaction
· Frequent negative emotional states
· Heightened emotional responses
· Brain development
· Physical changes
- risky beh = substance abuse etc. injuries and death
What part of brain develops at faster rate
The nucleus accumbens (rewards, pleasure) and amygdala (emotions) develop faster than prefrontal cortex (decision making)
Evidence of stronger response in adolescence than children or adults
Detection of amygdala response to facial expressions greater in adolescence
Nucleus accumbens response to receiving large monetary reward greater in adolescence
Puberty def
Puberty is a dynamic process whereby an individual first attains
the capacity to be fertile
Characteristics of pub
Sec sex charac appear
Physical growth
Reproductive competence is achieved
3 things that can affect puberty onset
Obesity = +
Undernutrition = -
Physical exercise= -
Brief Mestruation hpg axis process
Period
FSH from pit
Stim egg maturation and oestrogen release
Oest stops fsh so only one egg
And stim LH
LH causes mature egg to release
Progesterone increases to maintain uterus lining
Effect of prog when preg
High
Maintains lining throughout,
Suppresses everything else
Effect of testosterone on HPG axis in men
Inhibits gnrh and LH FSH production
Other name for kiss1R
GPR54
Effect of kiss1r mutation
Sexual immaturity
Failure of gonadal function
Hypogonadotropism
Where are the 2 kiss1 neuronal populations
Arcuate nucleus
Pre optic area
M effect of oestrogen on AVPV neurons
Positive feedback =stim gnrh neurons
Effect of oestrogen on arc nucleus neurons
-Ve feedback
Where does AVPV neuronsactivate the gnrh neuron
Cell body
Where does arc activategnrh-neuron
Activates the terminals
Sexual dimorphism in kiss1 cells inv AVPV
Very few in males compared to females
What neuropeptide does AVPV neurons express
Kiss 1, galanine, tyrosine hydroxyls
What nevropepticle does ARL neurons release
Kiss, neurokinin B. Dynorphin (Kndy)
Function of kiss1 from AVPV neurons
LH surge for ovulation
function of kiss1 from Arc
control pulsatile release on Gnrh and lh
