Tabel of content
Lecture 2.................................................................................................................................................2
Genes..................................................................................................................................................2
Pharmacology.....................................................................................................................................5
2. Genes and pharmacology...................................................................................................................8
Bear et al. Chapter 2...........................................................................................................................8
Carlson Chapter 4 - Psychopharmacology........................................................................................10
Genetics and Neuropsychology: A Merger Whose Times Has Come................................................21
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Lecture 2
Genes
A cell contains different chromosomes that consists of DNA.
The coded information that genes contain will be reproduced.
Genetics
DNA can not leave the cell nucleus, so it has to replicate itself to RNA (copy of one strand of DNA). RNA starts
building the gene product proteins. Some proteins become part of the body’s structure.
DNA is composed of base pairs Adenosine and Thymine and Cytosine and Guanine.
DNA vs. RNA
Human chromosomes
We have 23 pairs of chromosomes which makes 46. Edwards syndrome have an extra copy of chromosome 18
and Down syndrome have an extra copy of chromosome 23.
The sex chromosomes are X and Y females have XX and males have XY.
Sex-linked genes are the sex chromosomes X and Y on chromosome 23. Other genes are called autosomal
genes.
Sex-limited genes are present in both sexes but active mainly in one sex. These genes lay on autosomal genes.
Alleles
A different form of a gene short for allelomorph.
Polymorphic: A gene that has more than one allele is present on that location of the gene within a population.
One or two of more versions of a known mutation at the same place on a chromosome.
Genotypic interactions can be described as dominant of recessive. The allele that is expressed is the one that
leads to the dominant phenotype.
General terminology
A phenotype is a set of observable characteristics or traits of an organism. This can be something physical,
structure related, developmental, biochemical/physiological properties or behavior. A predisposition is a
complex set of risk factors that bias a person towards illness, but do not cause it.
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Homozygous & Heterozygous
Homozygous means 2 of the same genes and heterozygous means 2 different genes in one pair.
You inhered a dominant gene.
Heredity
X-linked recessive is different for boy
and girls because of the X chromosome.
Autosomal dominant inheritance
Huntington is caused by an autosomal-dominant mutation. There is a mutated HTT genes with some more
repetitions that leads to neuron degeneration.
Proteins and neurodevelopment
Proteins are long chains of amino acids. Proteins can be enzymes, transporters or signal transdunction
molecules.
Individual genes can code for differences, caused by genetically altered proteins. Proteins can regulate
neurodevelopment; influencing neuronal selection, migration, differentiation of synaptogenesis and synaptic
plasticity (important for learning)
Microcephalin gene
A gene that influences the size of the brain. Microcephaly means a small brain. There is a causal link between
the microcephalin gene and microcephaly. The zika virus disrupts the microcephalin gene which caused a small
brain for children.
Gene expression
Gene expression is the reading of genes resulting in the production of proteins.
Regulation of gene expression related to a wide range of mechanisms leading either to increase or decrease of
the production of certain gene products.
Epigenetics
Gene expression depends on the location in the body, developmental phase, experience, availability of food,
drug addiction, social isolation etc.
Everything we do has impact on which proteins become active.
Genes and environment
How can we distinguish between genes and environment? Looking at behavior makes it impossible to
distinguish.