Lecture week 4

Question 1

What is the endophenotype?

Answer 1

what is going on inside to cause the behavior

Question 2

What is the promotor region?

Answer 2

A spot on the DNA where the transcription molecule attaches

Question 3

What happens when the transcription molecule attaches in the promotor region?

Answer 3

DNA will open and RNA will copy a part of the gene. That creates a protein.

Question 4

What is gene regulation?

Answer 4

Genes can be turned on and off, depending on the signals that it gets, for example, from other cells.
It is most important to know when, how long, and how active the protein is.

Question 5

Name two ways how there can be vatiations in genes

Answer 5

mutations and polymorphisms

Question 6

What is a single nucleotide polymorphism

Answer 6

With SNP’s there is one nucleotide that is different. Depending on the place on the gene whether this will lead to different translation & transcription.

Question 7

The SNP’s only have effect when it affects the regulation of the gene. In what regions does the SNP affect the regulation of the gene?

Answer 7

• exon versus intron
• promoter region
• splicing site
• regulatory region

Question 8

What are some hormones and neurotransmitters that play a role in growth, development, stress and psychopathology

Answer 8

• Serotonin (eg. Transporter gene 5-HTT LPR)
• Cortisol (eg. Glucocorticoid and Mineralocorticoid)
• Receptor (GR/MR) genes
• Dopamine (eg. DRD4)
• Oxytocin (eg. OXTR)
• Brain-derived neurotrophic factor (BDNF)

Question 9

With the serotonin (5-HT) transporter polymorphism, people can have two variations. The short allele and the long allele. What does the kind of allele determine?

Answer 9

Dependent on which allele you have, it depends how much serotonin is released but also how many serotonin transporters and receptors there are.

Question 10

What allele combination gives the most self reported depression syptoms in combination with a higher number of stressful life events? and which one the least

Answer 10

The most: s/s
The least: l/l

(l/l is the most resilient)

Question 11

What is the gene that regulates the HPA-axis

Answer 11

Cortisol

Question 12

Define epigenetics

Answer 12

The effect of the environment on the expression of genes. This causes permanent or temporary changes in the regulation of the genes.

Question 13

What is DNA methylation?

Answer 13

It is an additional genetic layer. When there are a lot of methyl groups attached, the gene is not active. It influences the specialization or the activity of the cells. When the groups are moved, the gene will be transcribed. There has to be a signal that takes the groups on or off.

Question 14

True or false: Trauma may impact regulation of the DNA via epigenetics
and the activity of many different cells – tissues – organs – systems
(eg. GR receptors, HPA-axis, insulin, immune system)
DNA-methylation due to trauma may be limited to certain brain areas.

Answer 14

True

Question 15

What gene is related to changes in the HPA-axis

Answer 15

The GR gene

Question 16

People who committed suicide that had been abused in childhood had a higher level of methylation on the GR gene. Those with higher levels of methylation had less glucocorticoid receptors in the hippocampus. What does this indicate?

Answer 16

This indicated that if your cortisol level has been too high many times in your childhood, that the system might methylate your gene in the hippocampus. This leads to a lower expression of GR.

Question 17

Childhood trauma can also cause the methylation of what other genes?

Answer 17

5-HTT gene, OXTR gene and the BDNF