Heritability, Genes, and Neurogenetics Overview

Falconer Formula

Calculates heritability using twin study data.

Monozygotic Twins

Identical twins sharing 100% genetic material.

Dizygotic Twins

Fraternal twins sharing 50% genetic material.

Concordance Rate

Percentage of twins sharing a trait.

Heritability (h2)

Proportion of variance due to genetics.

Vp

Phenotypic variance, sum of genetic and environmental variance.

VG

Genetic variance contributing to trait differences.

VE

Environmental variance contributing to trait differences.

Karyotype

Visual representation of an organism's chromosomes.

Homologous Pair

Chromosome pairs from each parent.

Meiosis

Cell division producing haploid gametes.

Mitosis

Cell division producing diploid cells without variability.

DNA Structure

Double helix formed by nucleotide pairs.

Nucleotides

Building blocks of DNA, forming base pairs.

Adenine (A)

Base pairing with Thymine (T) in DNA.

Thymine (T)

Base pairing with Adenine (A) in DNA.

Guanine (G)

Base pairing with Cytosine (C) in DNA.

Cytosine (C)

Base pairing with Guanine (G) in DNA.

Semiconservative Replication

DNA replication method preserving one original strand.

DNA Polymerase

Enzyme synthesizing new DNA strands during replication.

Transcription

Process of converting DNA to mRNA.

Codon

Three nucleotides coding for an amino acid.

Gene Expression

Process of converting genetic information into proteins.

Epigenetic Processes

Regulatory mechanisms affecting gene expression without altering DNA.

Barr Body

Inactivated X chromosome in female cells.

Post Traumatic Slave Syndrome

Theory explaining adaptive behaviors from historical oppression.

C. Elegans

Model organism used in genetic studies.

Human Generation

Average span of 20 years in human studies.

Environmental Influence

External factors affecting trait development and expression.

Male pups breeding

Male pups bred with untraumatized female pups.

Mouse Epigenetics

Study of trauma effects on mice.

Acetophene exposure

Cherry blossom scent used in trauma studies.

HPA Axis

Stress response system important for tests.

FKBP5 methylation

Lower in Holocaust offspring than controls.

FKBP5 function

Linked to glucocorticoid receptor and cortisol.

PTSD differentiation

FKBP5 protein distinguishes trauma-exposed individuals.

Civil War study

Children of ex-POWs studied for mortality.

No-exchange ex-POWs

Had earlier mortality than others post-war.

POW status effects

Did not impact socioeconomic or marital status.

Y chromosome epigenetics

Possible transmission effects to offspring.

Gene definition

Expression or specific genetic conditions like Huntington's.

Huntington's Disease

Genetic disorder linked to chromosome 4.

Mitochondrial DNA

Inherited from maternal lineage, less information.

Nuclear DNA

Inherited from all ancestors, more complex.

mtDNA heteroplasmy

Variability in mitochondrial DNA inheritance.

Single nucleotide polymorphism (SNP)

Variation of one nucleotide in DNA sequence.

Indels

Insertions or deletions affecting gene function.

Mobile element insertion (MEI)

DNA segments that move within the genome.

Large deletions

Affect multiple genes in the genome.

Inversions

Chromosomal segments flip orientation.

Aneuploidy

Abnormal chromosome number, includes trisomy and monosomy.

Turner Syndrome

Condition caused by monosomy of X chromosome.

Amino acid changes

Genetic variations can alter protein sequences.

DNA Sequencing

Process to replicate and analyze DNA.

Linkage Analysis

Identifies trait-genetic marker co-segregation.

Association Study

Correlates genetic variants with traits in populations.

Anxious Mice

Hypothesis linking mouse anxiety to human behavior.

Chromosome 1

Location of significant fearfulness genes in mice.

Synteny homology

Shared gene arrangement between species.

Bendesky et al.

Study on parental care evolution in mice.

Monogamous mice

Mice that mate with one partner.

QTL analysis

Quantitative trait locus analysis for genetic mapping.

Membrane

Barrier surrounding cell, regulates entry/exit.

Selective permeability

Cell membrane allows specific substances to pass.

Cytoplasm

Gel-like substance within the cell membrane.

Nucleus

Cell organelle containing genetic material.

Rough endoplasmic reticulum (RER)

Site for mRNA translation into proteins.

Smooth endoplasmic reticulum (SER)

Synthesizes vesicles and processes proteins.

Golgi apparatus

Packages proteins into vesicles for transport.

Mitochondria

Organelles that produce ATP, the energy currency.

Adenosine triphosphate

Primary energy carrier in cells.

Lysosomes

Organelles that digest cellular waste.

Organelle

Cell structure with a specific function.

Cell body (perikaryon)

Main part of a neuron containing the nucleus.

Dendrites

Extensions of neurons that receive signals.

Axon

Long projection that transmits impulses away.

Axon terminal

End of axon where neurotransmitters are released.

Synapse

Junction between two neurons for communication.

Neurotransmitters

Chemical messengers transmitting signals across synapses.

Receptors

Proteins that bind neurotransmitters to initiate responses.

Sodium potassium pump

Transports sodium out and potassium into cells.

Ligand Ion channel

Opens in response to neurotransmitter binding.

Raphe nuclei

Cluster of neurons producing serotonin.

Serotonin

Neurotransmitter involved in mood regulation.

Zygote

Single cell formed from sperm and egg.

Blastocyst

Early stage of embryonic development.

Embryo

Developing organism from weeks 3-8 of pregnancy.

Fetus

Developing organism from week 9 to birth.

Neurexins and neuroligins

Molecules connecting pre and postsynaptic neurons.

Serotonin reuptake transporter (SERT)

Transports serotonin back into presynaptic neurons.

Positron emission tomography (PET)

Imaging technique assessing neurotransmitter binding sites.

Magnetic resonance imaging (MRI)

Imaging technique for structural brain differences.

Functional magnetic resonance imaging (fMRI)

Measures brain activity by detecting blood flow.

Psychopharmacology

Study of drug effects on mental illness.

Pharmacodynamics

Effects of drugs on their targets.

Pharmacokinetics

Movement of drugs within the body.

Pharmacogenetics

Genetic variation affecting drug responses.

Monoamine oxidase A (MAOA)

Enzyme that metabolizes serotonin.

Monoamine oxidase inhibitors (MAOI)

Drugs that increase serotonin by inhibiting MAOA.