Brain Programming: Early-life, Epigenetics and Environment
Hoorcollege 1: Early-life and brain/parent-offspring conflict, Bart Pollux 2
Hoorcollege 2: Intro about epigenetics, Pernette Verschure 11
Techniques in epigenetics, Pernette Verschure 18
Hoorcollege 3: Epigenetic and mental retardation, Aniko Korosi 21
Hoorcollege 4: Early life nutrition and cognitive functions, Hannah Junckers 26
Hoorcollege 5: Dutch hunger winter cohort, Susanne de Rooij and Mirjam van Zuiden
29
Hoorcollege 6: Epigenetic and metabolic vulnerability, Torsten Plosch 35
Hoorcollege 7: Early-life stress, synapse plasticity and adaptation, Harm Krugers 37
Hoorcollege 8: SSRI and pregnancy, Jocelien Olivier 41
Hoorcollege 9: Nutrition and preterm, Caroline de Theije and Cora Nijboer 46
1
,Hoorcollege 1: Early-life and brain/parent-offspring conflict, Bart Pollux
article:
- The core of this hypothesis is that psychosis and autism represent two extremes on a
cognitive spectrum with normality at its center. Social cognition is thus
underdeveloped in autism, but hyper-developed to dysfunction in psychosis.
- These alterations are caused by alterations in developmental and metabolic systems
affected by genomic imprinting, notably via effects of genes that are imprinted in the
brain and in the placenta
the effect of adverse early life events on the developments and vulnerability to disease later
in life
- from the picture, the time before birth is missing → pregnancy: very important for
development
long time: the relationship between mother and embryo is intimate and loving
but not: battlefield → placenta is a battlefront for parent-offspring conflict (POC)
- may be responsible for:
- pregnancy related illness
- diseases later in life
intro
placenta:
- a temporary and sex-specific organ
- highly complex organ: depends on interactions
- two genetically different individuals: consist of a maternal and fetal part
- highly vascularized, but the vascular systems never mix
evolution of placentas
- how often do they evolve
- why do they evolve
- how do they evolve
- what are their consequences
parent-offspring conflict
Robert Trivers (1974): relationship between mother and developing embryo is warm and
loving (mother and fetus are working together to make the pregnancy a success) → there
can indeed be conflicts between mother and offspring which takes place in the placenta
(battlefield)
mother: optimize their own fitness by providing as many offspring as possible with
just sufficient resources
- maximize their own fecundity
- optimizing offspring size
offspring: each individual wants more than merely sufficient resources
- maximize offspring size
2
,traditional view: the mother is in charge, offspring are merely passive recipients of maternal
sources
Trives argued that this is not always the case, because:
- offspring are active participants, which can lead to conflict
- the developing offspring can influence the distribution of maternal resources through
gene expression
manipulation of resources by offspring:
- prenatal period
- chemical signals
- postnatal period
- behavioral signals
In which species can parent-offspring conflicts (POCs) possibly occur?
3
, genomic imprinting
not everybody could understand the idea from Trives about the POC → his ideas were
neglected and they were controversial
until: David Haig → parent-offspring conflicts are essentially genetic conflicts between
maternal and paternal genes
- inter genomic conflict: maternal genes in the mother versus paternally-derived genes
in the offspring
- intra genomic conflict: maternally-derived genes in the offspring versus
paternally-derived genes in the offspring (within genome)
paternally-derived genes: increase the amount of resources from the mother to the fetus
maternal genes and maternally-derived genes: will be selected to limit any transfer that is in
excess of some maternal optimum.
- only limit the excessive investment
the conflict between maternal and paternal resource acquisitions genes is driving the
silencing of one of the parental alleles through natural selection
genomic imprinting:
- An epigenetic phenomenon that causes genes to be expressed in a
parent-of-origin-specific manner.
- It is an epigenetic process that involves DNA methylation and histone methylation
without altering the genetic sequence.
- These epigenetic marks are established ("imprinted") in the germline (sperm or egg
cells) of the parents and are maintained through mitotic cell divisions in the somatic
cells of an organism.
4
Hoorcollege 1: Early-life and brain/parent-offspring conflict, Bart Pollux 2
Hoorcollege 2: Intro about epigenetics, Pernette Verschure 11
Techniques in epigenetics, Pernette Verschure 18
Hoorcollege 3: Epigenetic and mental retardation, Aniko Korosi 21
Hoorcollege 4: Early life nutrition and cognitive functions, Hannah Junckers 26
Hoorcollege 5: Dutch hunger winter cohort, Susanne de Rooij and Mirjam van Zuiden
29
Hoorcollege 6: Epigenetic and metabolic vulnerability, Torsten Plosch 35
Hoorcollege 7: Early-life stress, synapse plasticity and adaptation, Harm Krugers 37
Hoorcollege 8: SSRI and pregnancy, Jocelien Olivier 41
Hoorcollege 9: Nutrition and preterm, Caroline de Theije and Cora Nijboer 46
1
,Hoorcollege 1: Early-life and brain/parent-offspring conflict, Bart Pollux
article:
- The core of this hypothesis is that psychosis and autism represent two extremes on a
cognitive spectrum with normality at its center. Social cognition is thus
underdeveloped in autism, but hyper-developed to dysfunction in psychosis.
- These alterations are caused by alterations in developmental and metabolic systems
affected by genomic imprinting, notably via effects of genes that are imprinted in the
brain and in the placenta
the effect of adverse early life events on the developments and vulnerability to disease later
in life
- from the picture, the time before birth is missing → pregnancy: very important for
development
long time: the relationship between mother and embryo is intimate and loving
but not: battlefield → placenta is a battlefront for parent-offspring conflict (POC)
- may be responsible for:
- pregnancy related illness
- diseases later in life
intro
placenta:
- a temporary and sex-specific organ
- highly complex organ: depends on interactions
- two genetically different individuals: consist of a maternal and fetal part
- highly vascularized, but the vascular systems never mix
evolution of placentas
- how often do they evolve
- why do they evolve
- how do they evolve
- what are their consequences
parent-offspring conflict
Robert Trivers (1974): relationship between mother and developing embryo is warm and
loving (mother and fetus are working together to make the pregnancy a success) → there
can indeed be conflicts between mother and offspring which takes place in the placenta
(battlefield)
mother: optimize their own fitness by providing as many offspring as possible with
just sufficient resources
- maximize their own fecundity
- optimizing offspring size
offspring: each individual wants more than merely sufficient resources
- maximize offspring size
2
,traditional view: the mother is in charge, offspring are merely passive recipients of maternal
sources
Trives argued that this is not always the case, because:
- offspring are active participants, which can lead to conflict
- the developing offspring can influence the distribution of maternal resources through
gene expression
manipulation of resources by offspring:
- prenatal period
- chemical signals
- postnatal period
- behavioral signals
In which species can parent-offspring conflicts (POCs) possibly occur?
3
, genomic imprinting
not everybody could understand the idea from Trives about the POC → his ideas were
neglected and they were controversial
until: David Haig → parent-offspring conflicts are essentially genetic conflicts between
maternal and paternal genes
- inter genomic conflict: maternal genes in the mother versus paternally-derived genes
in the offspring
- intra genomic conflict: maternally-derived genes in the offspring versus
paternally-derived genes in the offspring (within genome)
paternally-derived genes: increase the amount of resources from the mother to the fetus
maternal genes and maternally-derived genes: will be selected to limit any transfer that is in
excess of some maternal optimum.
- only limit the excessive investment
the conflict between maternal and paternal resource acquisitions genes is driving the
silencing of one of the parental alleles through natural selection
genomic imprinting:
- An epigenetic phenomenon that causes genes to be expressed in a
parent-of-origin-specific manner.
- It is an epigenetic process that involves DNA methylation and histone methylation
without altering the genetic sequence.
- These epigenetic marks are established ("imprinted") in the germline (sperm or egg
cells) of the parents and are maintained through mitotic cell divisions in the somatic
cells of an organism.
4
