Lecture 7 part I Flashcards
(33 cards)
epigenetic programming
this idea that epigenetic changes during the early life period can sort of program neural systems for long periods of time and then impact the way an adult organism will interact with its environment
developmental plasticity
- developmental processes depend on the presence of particular genes, the timing of gene activation, selective silencing of genes
- Development proceeds due to the actions of transcription factors
the transcription factors that set things off are present in the egg, but following that gene expression occurs in waves.
this represents what idea?
- developmental plasticity
- Genes can code for transcription factors
- Gene expression can begin more gene expression
- Certain genes can turn on the expression of certain genes and those genes themselves are transcription factors which can turn on the expression of other genes
- epigenetic mechanisms might mediate the dynamic interplay between _____ and _______
- this represents what idea?
- genes; environment
2. developmental plasticity
T or F: epigenetic mechanisms may allow for developmental plasticity in response to changing environments
True
- The timing of gene expression programs is so important for the development of particular structures
- The timing of particular environmental events and how those might specifically interplay
Epigenetic mechanisms allow ….
-variation at the level of gene expression allowing the phenotype of an organism too vary in response to environmental experience
gene expression —->phenotype
two types of epigenetic changes
- context dependent
- germ line dependent
context dependent
- across lifespan, can be reversible
- experience during development affects adult phenotypes
- experiences during adulthood affect subsequent adult phenotypes
- experience-dependent behaviors can persist in multiple generations as long as each generation is exposed to the experience (social transmission)
social transmission is part of what type of epigenetic change ?
context dependent
example of context dependent
- Rat mothers who groom and lick their pups create resilient adult rats. This resilience in the adult offspring is then pass on to the next generation. NOT because of some biology but because the adult rats were licked and groomed as pups so they do the same to their offspring (social transmission) and hence making their pups resilient as well
- The context was passed on NOT the genotype
T or F: in context dependent if the context is not the same then the gene won’t be pass on
true
germ-line dependent
- imprinted onto the genome
- transmitted to future generations
- endocrine disruptors may increase risk for reproductive diseases and cancer in future generations
- Talking about some epigenetic modifications which impacts gene expression and alters phenotype which actually becomes independent of the context that generated it
- This modification could be passed down to the next generation and the next and so on through the germ-line
There is a lot of epigenetic programming that is happening that is necessary just for developmental processes so if the developing fetus is exposed to any endocrine disruptors that exposure ends up impacting the processes that were already ongoing
this statement represents which idea?
germ-line dependent
germ-line dependent example
exposing rat pregnant rat moms to vinclozolin increases cancer in the male offspring and fertility problems and that effect persists
-All future male generations from this moment on will have cancer and fertility problems as adult rats
in which type of epigenetic change do we See the effect on the phenotype out several generations pass the event that initiated
germ line dependent
why should we care about early life?
- understanding how the external world (not just physical but also social) shapes the brain and behavior has critical implications for neuroscience
- long term health problems that can result from lower socioeconomic environments
- vicious cycle can exist in which abused children grow up to become abusive parents
-Understanding how particularly certain types environments/ experiences impact development is important for understanding adult outcomes
• Can provide information on where we need to intervene and what interventions would be useful
Experiencing adverse events is linked with adverse health outcomes
- Can help understand long term drug taking behavior, followed by no longer taking the drug but the propensity for relapse has a clear epigenetics link
- Genes can make some people more predisposed more likely to relapse in the future
- We can understand what is being programmed in terms of sociability and future caregiving behavior by that early life environment. This ways children who experience abuse have a chance to break this vicious cycle of abuse
why study maternal care
- over 95% of mammalian species are uni-parental with the mother solely providing care
- mothers are the sole caregivers in most species
T or F: Maternal behavior is highly conserved across species and moms are incredibly motivated to care for their infants
True
mother-infant bond example
-sheep are born mobile and can run away, so in order for mothers to prevent their young running away and being nursed by another sheep mom they develop SELECTIVE ATTACHMENT towards their offspring
○ Within minutes of delivering the mom can recognize her offspring’s odor and she develops an attachment to that odor and so if another offspring comes up and tries to nurse she will actively reject that offspring, this way she’s only exhibiting nursing behavior towards her offspring
the nature of maternal behavior is influenced by the development of ?
the young at birth
rodents
- development of young at birth
- social structure
- maternal behaviors
- altricial/immobile
- solitary, nest bound
- nurse, licking, grooming, nest build, retrieve displaced infant, protect, no selective attachment
- Altricial: really really immature , can’t open their eyes at all, can hear, can barely move, have a difficult time thermal regulating
- Extremely dependent on mom for survival
- So if they get separated from mom they have no way of finding their way back to mom
- Caring behavior is really important for rodents
Don’t develop selective attachment: they will care for any baby whether is theirs or not
T or F: rodents don’t develop selective attachment: they will care for any baby whether is theirs or not
True
sheep and goats
- development of young at birth
- social structure
- maternal behaviors
- precocial/ mobile
- herds of unrelated individuals
- nurse, lick, groom, protect, selective attachment
primates
- development of young at birth
- social structure
- maternal behaviors
- semiprecocial/ semimobile
- social groups
- nurse, lick, groom, protect, carry infants, selective attachment