Lecture 6

Question 1

Emotions in brain circuits

Answer 1

1. Detection of environmental signals: Senses and Thalamus
2. Interpretation of environmental signals: Hippocampus and Amygdala
3. Evaluation of these signals: PFC, NAc, Dopamine
4. Action preparation: Motor cortext, Hypothalamus, Brain stem
5. Visible behaviour

Question 2

Psychological disorders regarding detection of environmental signals

Answer 2

• Autism
• ADHD
• Stress

Treatment: reduction impulses

Question 3

Psychological disorders regarding interpretation of environmental signals

Answer 3

• PTSD
• Anxiety disorders

Treatment: reduction of overactive response

Question 4

Psychological disorders regarding evaluation of environmental signals

Answer 4

• ADHD
• Stress
• PTSD
• Addiction

Treatment: restore cognitive control

Question 5

Psychological disorders regarding action preparation

Answer 5

• PTSD

Treatment: restore autonomic nervous system

Question 6

Treatment of ADHD

Answer 6

• Activating the brain, primarily PFC
• Medication:
  - Ritalin: reuptake inhibitor (noradrenergic)
  - Stratera Concerta (noradrenergic)
  - Prozac: reuptake inhibitor (serotonergic)
  - Catapres: for tics and ADHD (noradrenergic)
  - Wellburtin: with depression (noradrenalin and dopamine reuptake inhibitor
  - Adderal: reuptake inhibitor (dopaminergic)
• Selfmedication: smoking
• Nutraceuticals: attend

Question 7

Dopamine synthesis areas

Answer 7

• Substantia Nigra (Pars Compacta and Pars Reticulata)
• Ventral Tegmental Area

Question 8

Dopamine projection areas

Answer 8

• Nigro-striatal projection
• Pallidum
• Caudate Nucleus and Putamen
• Frontal lobe

Question 9

Functions of the different dopamine pathways

Answer 9

• Nigro-striatal: Modulates cortical motor control and action selection. Mediated via cortico-striatal-loop
• Meso-cortical/limbic: Reward processing, motivation, modulation of cognitive control

Question 10

Dopamine receptors

Answer 10

All dopamine receptors are metabotropic and G-protein-coupled
Two subgroups: D1 receptors (excitatory, increase cAMP) and D2 receptors (inhibitory, decrease cAMP).

Reuptake via DAT

Question 11

Basal Ganglia Motor loops dopamine brain area

Answer 11

• Body movement loop: Putamen
• Oculomotor loop: Caudate (body)
• Prefrontal loop: Anterior caudate
• Limbic loop: Ventral striatum

Question 12

Parkinson’s Disease

Answer 12

Degeneration of the dopaminergic neurons in SN

Bradykinesia: slowing/loss of movements mechanism: increase of motor threshold

Question 13

Nigro-striatal system

Answer 13

SN: dopamine
BG: GABA
Thalamus and Cortex: Glutamate

SN and motor cortex excite Dorsal Striatum
Dosral striatum inhibits Globus Pallidus which inhibits Thalamus
Thalamus excites motor cortex

Question 14

Deep brain stimulation

Answer 14

• Mainly successfull in Parkinsons, Tourettes
• Mainly stimulation of the subthalamic nucleus
• Experimental reseach in OCD, epilepsy, addication

Question 15

Dopamine stimulation Reverse U shaped curve

Answer 15

Working memory performance depends on D1R stimulation. It shows a reverse U shaped curve meaning that both very high and low D1R stimulation results in low working memory performance and medium stimulation results in high performance,

Question 16

Noradrenaline synthesis and projections

Answer 16

Synthesis: Locus Coeruleus (LC)

Projection: All over the brain

Reuptake via Norepinephrine Transporter (NET)

Question 17

Norepinephrine functions

Answer 17

Regulates arousal state (Sympathetic Nervous System)
Fight or flight response and stress
Released by adrenal medulla as a hormone.
Memory consolidation
Sleep wake cycle

Question 18

Norepinephrine receptors

Answer 18

• All are metabotropic and G-Protein-coupled
• Subtypes: alpha 1A, alpha 2A, beta 1-3

Question 19

Norepinephrine pharmacology

Answer 19

NE increased by:
- Antidepressants: MAO blockers, Tricyclic antidepressants
- ADHD meds: Ritalin (reuptake blocker), Strattera (reuptake blocker), Modafinil
- Stimulants: Amphetamine, Cocaine

Question 20

Effects of Methylphenidate (Ritalin)

Answer 20

Inverted U shape for dosage and spatial working memory. Meaning a medium dosage has the best cognitive performance.

Increases Dopamine and Norepinephrine release in the PFC. Blocks reuptake.

Question 21

Serotonin synthesis/projections and functions

Answer 21

Synthesis: Raphe nucleus

Projections: all over the brain

Functions: gut motility and vasculature

Mood, anxiety, arousal, circadian rhythm, eating disorders, migraine, pain, drug abuse

Question 22

Serotonin receptors

Answer 22

Ionotropic receptor: 5-HT3

Metabotropic receptors:
5-HT1
5-HT2
5-HT4, 6, 7
5-HT5

Question 23

Funcion of Serotonin

Answer 23

• Modulation of basic psychological function: mood, appetite, sleep, sexuality
• Implicated in depression (most antidepressants block 5-HT reuptake)
• Implicated in aggression (high serotonin levels)
• Stimulates vomiting

Question 24

Antidepressants

Answer 24

• MAO inhibitors: inhibit breakdown of all monoamines
• Tricyclic antidepressants: inhibit reuptake of serotonin and norepinephrine
• SSRI’s: inhibit reuptake only of serotonin

Question 25

Modulation

Answer 25

Neurotransmitters that modulate do not directly evoke EPSP’s or IPSP’s. They modify the effectiveness of EPSP’s generated by other synapses with transmitter-gated channels