prenatal stress development Flashcards
prenatal stress and adult offspring rats
barbazages
-pregnant mother exposed to stress
-maternal corticosterone secretion during pregnancy on HPA axis of adult offspring
-prenatal stressor was repeated restraint
-2 hrs later corticosterone level was high
–hippocampal type 1 and 2 corticosterone receptors in male adult rats submitted to prenatal stress in utero
–decrease in type 1 hippocampal corticosteroid receptors in prenatally stressed adults
Salm rats
-pregnant females exposed to stress
-30% increase in vol of lateral amygdala nucleus compared to controls
schulz dutch hunger winter 1944
-extreme stress from starvation
-less than 1000 calories during pregnancy
-women split into those early gestation, mid gestation exposure or late gestation exposure
–early: normal birth weight, high risk of obesity and cardiovascular disease
–mid: low birth weight, reduced renal function
–late: low birth weight, small throughout life, less obesity rates
COG function
-early gestation did stroop task
–lower cog function at age 56-59
–no diff at age 19
–problems not seen until later age
–early manisfestation of accelerated aging process
epigenetics
when foetus is developing
-good idea if somehow through the mother the baby can be pepared for the environment e.g if baby is going to be born into huge food scarcity
post natal stress and aging
-after birth is critical period
-brain develops for long time
-rats have smaller window than humans
Brunson research into post natal stress
-rat mothers and pups exposed to 2 environments: harsh or comfrtable
-stress effects are evident after early stress but gone by 12 months (mother limited nesting material, less time nursing etc)
COG
-4-5 months, born early life stress rats and controls require progressively less time to find hidden platform in Morris underwater maze test
-by 12 months born early life stress rats require sig longer time (hippocampus not working as it should
-impact of exposure to stress does not maifest straight away
-physical change in brains in those exposed to stress in early life
Lu et al
-1 group housed individually, 1 group housed in groups
-indiv = stress
-did morris underwater maze task
-group raised rats performed better
-isolation effects can be reversed by later group housing
-meausre of new cells in hippocampus
-stress prevents neurogenesis in hippo even though it is highly plastic
human post natal stress
gunner et al
-romania long history of children in orphanages
-6-12 yr olds
-RO: at least 8 months of first years of life in orphanage
-EA: early adopted, before 4 months
-CB: canadian born and raised by family of origin (control)
-measured cortisol
-RO had higher cortisol
-possible risk factors: privation of basic needs, exposure to infectious agents
PSS
psychosocial short stature
HSS
hyperphagic short stature
characteristics of PSS
-abuse dwarfism and psychosocial dwarfism
-failure to grow beyond infancy due to psychosocial circumstances
HSS characteristics
excessive eating not motivated by hunger
-normal bmi
-maladaptive hypothalamic response to neg emotions
-growth failure reversable when moved to nurturing environment
orphans in WWII germany
-compared children in 2 state run orphanages
-similar diet medical attention and similar environment
-diff was the women in charge
-2 identical orphanages run by diff women
-A was attentive and nurturing
-B was minimal contact and cold
-A children grew rapidly, B had slow growth/short stature
-when women from B took over A, growth in A declined and B accelerated
-Schwarz from B had few favourites who thrived comapred to B, they then were transferred to A and thrived even more
PSS mechanism
stanhope et al
-growth hormone (GH) insufficiency
-do not respond to GH treatment without psychosocial intervention
-2 lesions in hypothalamic pituitary growth axis which are reversable
-cortisol abnomalities not characteristic
-some discussion of ACTH but only in a few cases
