Brain chemistry 2 + knowledge clips gut Flashcards
Where is melatonin produced?
Pineal gland
Know where it is located (p14)
Where is histamine produced?
Mast cells
Tuberomamillary nucleus (posterior hypothalamus)
Where is serotonin (5-HT: 5-hydroxytryptamine) produced in the brain?
Raphe nuclei (dorsal, medial, caudal) (achterkant pons)
Where is norephinephrine/noradrenaline produced?
Locus coeruleus (onder raphe nuclei, achterkant pons, maar iets lager
What do the substantia nigra do? Pinpoint them p.15
black dots of neurons that make dopamin.
Recognize substantia nigra!
What are the four dopamine pathways? (and their nuclei)
- Nigrostatial (substantia nigra)
- Tuberoinfundibular (arcuate nucleus)
- Mesolimbic (ventral tegmental area: VTA)
- Mesocortical (VTA)
p.15
Dopamine can be metabolized into…. (3)
- DOPAC
- HVA
- noradrenaline -> (can in turn be metabolized into adrenalin)
What is an important enzyme that helps to convert/metabolize dopamine into other substances/neurotransmitters? (metabolites, noradrenaline, adrenaline, serotonin)
MAO = monoamine oxidase
What is the serotonin theory? What is a limitation?
chemical imbalance: depletion 5-HT in depressed patients.
Limitation: not all individuals respons to 5-HT agonists or SSRI
What do SSRI do?
Selective serotonin reuptake inhibitors
SSRI block the serotonin reuptake
What are current treatments for depression?
-SSRI
- 5-HT receptor agonists
- TCA
- MAO inhibitors
- supplements (5-HTP)
Half-life of antidepressants are quite long. What can be the risk of taking, for instance, 5-HTP?
If 5-HTP is taken together with something like an SSRI, it can cause the serotonin syndrome -> seizures -> die
What is the link between aggression and serotonin?
Too low serotonin = too much aggression link
However, lower levels of serotonin (5-HT) are perhaps aspecific because they are also related with migrain, depression, OCD, anxiety, gambling
What does alcohol do to serotonin levels?
Alcohol lowers tryptophan, which is a precursor for serotonin synthesis and thus also lowers 5-HT synthesis (-20%!)
Alcohol leads to aggression in people that….
already have low levels serotonin
Alcohol can bind to GABA, leading to a ….. effect
sedating
What happens during Parkinson’s disease in the brain? What part is most effected?
Accumulation of alfa-synuclein depositions, which causes Lewy bodies in neurons in the brain. Substantia nigra mostly affected.
-> disrupted connection of substantia nigra with basal ganglia which regulate movement: leading to tremor etc
What happens during AD?
- Proteinopathy (accumulation of amyloid plaques and neurofibrillary tangles)
- Leads to massive death of neurons.
- Cholinergic disturbances: n. basalis of Meynert = cognitive dysfunction
PD: not only dopamine disturbances, also …. disturbances
norepinephrine, serotonin
AD: what types of neurotransmitters have disturbances?
Dopamine,serotonine, norepinephrine disturbances
What happens to the locus coeruleus (nucleus in pons of brainstem) in AD?
Completely gone in AD: vasoconstriction
Which statements are true:
- Agressive behaviour is linked to a reduced serotonergic neurotransmission
- Current pharmacological treatments for depression solely consists of SSRI’s
- Alcohol intake leads to increased levels of serum tryptophan
- AD and PD are characterized by abundant serotonin, dopamine and norepinephrine losses in the brain (and periphery)
1, 4 are true
Phenylalanine, tryptophan, histidine: essential or non-essential AA?
essential
What are some GABA-rich foods?
tomatoes, potatoes
What is a food high in acetylcholine?
aubergine
Most amino acid rich foods are …. from origin
animal-based
What 5 factors determine whether certain amino acids/etc reach the brain?
- transporter proteins across the BBB
- Influence from non-neuronal tissues (GI tract, peripheral enzymes)
- Cooking methods, fresh vs processed, baked,..
- seasonal, geographical, species-aspects
(plant species, soul, nourishmnet,..) - micronutrient & trace element status
What are the steps in making serotonin?
Tryptophan -> 5-HTP -> Serotonin
What are the steps in making dopamine & noradrelane?
Tyrosine -> L-dopa -> dopamine -> noradrenaline
Where is epinephrine/adrenalin produced?
- Central adrenergic cell bodies
● Ventral/dorsal group -> medulla oblongata (onder pons)
● Catabolized out of norepinephrine (!)
● Axonal projections ≈ noradrenergic systems
Where is dopamine produced?
● Substantia nigra
● Tuberoinfundibular pathway
● Mesolimbic pathway
● Mesocortical pathway
Where is acetylcholine produced?
- nucleus basalis of meynert (see image p. 16)
- three other nuclei
p.16:
1. Where does the cholinergic pathway start?
2. Where does the serotonergic pathway start?
3. Where does the Histaminergic pathway start?
4. Where does the Dopaminergic pathway start?
5. Where does the Noradrenergic pathway start?
- Cholinergic nucleus at basalis of meynert
- Serotonergic nucleus at Raphe nuclei
- Histaminergic nucleus at tuberomammilary nucleus
- Dopaminergic nuclei, substantia nigra, Ventral tegmental area (VTA)
- Noradrenergic nucleus at locus coeruleus
