Lecture 2 Summary - Prenatal Development, Genetics, and Brain Development

Flashcards on Prenatal Development Hazards, Drugs, Maternal Factors, Genetics, and Brain Development

Miscarriage (Spontaneous Abortion)

The spontaneous end of a clinically recognized pregnancy; approximately 15% of pregnancies in the U.S. end in miscarriage.

Teratogens

Environmental agents that can cause harm to the fetus, with effects depending on the timing of exposure. The embryonic period (3rd to 9th week) is when teratogens have the most potential for harm.

Thalidomide

A drug prescribed in the early 1960s for morning sickness that caused major limb deformities when taken between the 4th and 6th week of pregnancy.

Dose-Response Relation (Teratogens)

The more exposure a fetus has to a harmful agent, the more likely and severe the effects are.

Fetal Programming

The long-term effects of prenatal experiences on adult physiology, as demonstrated by the Dutch Hunger Winter study.

Sleeper Effects

The impact of a teratogen may not be evident until years later, as seen with diethylstilbestrol (DES).

Isotretinoin (Accutane)

A prescription drug known to be a teratogen, causing severe birth defects or fetal death.

Neonatal Abstinence Syndrome (NAS)

Occurs when fetuses exposed to opioids in the womb experience withdrawal, with symptoms including low birth weight, feeding and breathing issues, and seizures.

Sudden Infant Death Syndrome (SIDS)

The unexplained death of an infant under 1 year, typically between 2-5 months, linked to a biological issue and an environmental stressor like limited oxygen. Risk reduced by placing infants on their backs.

Fetal Alcohol Spectrum Disorder (FASD)

Can result from prenatal alcohol exposure, leading to facial defects, intellectual disabilities, attention problems, and hyperactivity.

Environmental Pollutants (Prenatal)

Exposure to pollutants like toxic metals, plastics, pesticides, and air pollution can harm the fetus, especially in low-income neighborhoods.

Folic Acid (Prenatal)

An essential nutrient; its deficiency during pregnancy increases the risk of neural tube defects, such as spina bifida.

Rubella (Prenatal)

Can lead to birth defects like deafness and blindness if contracted during pregnancy.

Zika Virus (Prenatal)

Infection during pregnancy can lead to microcephaly, affecting brain development.

HPA Axis and Cortisol Levels

Stress during pregnancy can alter the HPA axis and cortisol levels, impacting fetal brain development and long-term stress response.

Minnesota Study of Twins Reared Apart

A study that explored nature vs. nurture by observing how identical genomes function in different environments.

Epigenetics

The concept that gene expression can be influenced by environmental experiences.

Genotype

The inherited genetic material.

Phenotype

The observable traits, including physical and behavioral characteristics.

Environment (Genetics)

Everything influencing an individual beyond their genetic makeup, including prenatal experience.

Random Assortment (Genetics)

During gamete formation, chromosomes are shuffled randomly, ensuring no two individuals (except identical twins) have the same genotype.

Crossing Over (Genetics)

During gamete division, sections of DNA from chromosome pairs swap, leading to further genetic diversity.

Mutation (Genetics)

Changes in DNA, which may be spontaneous or caused by environmental factors; can contribute to evolution.

Allele

Variants of a gene that influence traits, such as eye color.

Regulator Genes

These genes control the activity of other genes, turning them on or off.

Polygenic Traits

Human traits, such as intelligence, that are influenced by multiple genes, not just one.

Phenylketonuria (PKU)

A genetic disorder where individuals with a defective gene on chromosome 12 cannot metabolize phenylalanine; managed with a special diet to prevent intellectual impairment.

MAOA Gene (and Abusive Parenting)

Individuals with a less active version of the MAOA gene, who also experienced severe maltreatment, were more likely to engage in antisocial behavior as adults.

Genetic Nurture

A child's educational outcomes were partially influenced by parental alleles that the child did not inherit, suggesting that parents' genetic makeup affects the family environment.

Neurogenesis

The birth of neurons; begins around 42 days after conception and continues throughout life, especially in the hippocampus.

Arborization

The growth and branching of dendrites, allowing neurons to form complex connections.

Myelination

The formation of the myelin sheath around axons; begins prenatally and continues into early adulthood.

Synaptogenesis

The formation of synapses between neurons; starts during prenatal development and continues after birth.

Neurons

The basic units of the brain's informational system, with over 100 billion in the human brain.

Glial Cells

Support neurons in a variety of ways, including the formation of myelin sheaths around axons to enhance signal transmission.

Cerebral Cortex

Constitutes 80% of the human brain and is the 'gray matter,' divided into four main lobes: occipital, temporal, parietal, and frontal.

Corpus Callosum

A bundle of nerve fibers that connects the two hemispheres of the brain, enabling communication between them.

Cerebral Lateralization

Each hemisphere specializes in different modes of processing; for example, the left hemisphere is more active in processing speech, while the right hemisphere processes faces.

Experience-Expectant Plasticity

Refers to the role of species-typical experiences (like visual and auditory stimuli) in shaping brain development. If the expected experiences do not occur, development may be compromised.

Sensitive Periods

Windows of time during which the brain is especially receptive to certain environmental stimuli, which play a crucial role in organizing neural circuits.

Experience-Dependent Plasticity

Refers to how the brain continuously reorganizes itself throughout life based on individual experiences unique to the individual.