Brain chemistry 1 Flashcards
What is the definition of neurotransmission?
Definition of neurotransmission: “Process by which neurons communicate with one another across synapses using neurotransmitters or ionic currents.”
Recall some differences in electrical vs chemical neurotransmission
Electrical:
distanse pre-postsynaptic cell 4 nm
Ionic current
Gap junction channels (p.11)
Synaptic delay virtually absent (<0.3 ms)
Bidirectional direction of transmission
Chemical:
distanse pre-postsynaptic cell 20-40 nm
Chemical transmitters
Synaptic vesicles
Synaptic delay at least 0.3 ms, usually 1-5 ms
Unidirectional transmission
Not only axon-dendrite, but also axon-X and axon-X are possible between brain cells
axo-axonic (two axons: lange stukken)
axo-somatic (axon- naar celmidden)
Myelin sheets: produced out of..
Signal transferred over …
omega3 FA
nodes of Ranvier, spaces between myelin.
After chemical synapse communication, what happens to the neurotransmitters?
- Neurotransmitters are either taken back by the presynaptic cell
- Or are degraded by enzymes
What receptor subtypes were discussed?
- Ionotropic
- Metabotropic
How does the ionotropic receptor function?
Neurotransmitter binds to ionotropic receptor, channel opens. Ions can go through and enter neurons
What are examples of receptors that are ionotropic?
- Nicotinic acetylcholine (nACh) (at neuromuscular junction)
> Works by influx/efflux of sodium and potassium
- Nicotinic acetylcholine (nACh) (at neuromuscular junction)
- GABA receptors
> Influx of negative chloride ions (C-)
> Inhibitory (sleep, sedation)
> E.g. Alcohol can bind to this receptor - Glutamate receptors
(learning, memory) - Serotonin
How does the metabotropic receptor function?
neurotransmitter binds, cascade with production of ATP, second messengers, open channel next to it, channel opens and adrenaline or serotonin (or something else?) can enter
One neuron forms/receives 1000 to 10.000 synapses
True/false
True
NT can induce long-term changes within target cells, lasting hours or even days
True/false
True
Which cells are also able to produce, sequester and store NT ?
Astrocytes
What do autoreceptors on presynaptic terminals do?
terminate further release
What two main classes of neurotransmitters exist?
Small-molecule transmitters
(~150-190 Da)
-> catecholamines
->indolamines
-> amino acids
Neuro-active peptides (~1,000-5,000 Da)
-> short polymers of amino acids
Tyrosine is the precursor for these neurotransmitters:
That belong to the group of..
- dopamine
- norepinephrine
- epinephrine (adrenalin)
Catecholamines
Tryptophan is the precursor for the neurotransmitter….
That belongs to the group of..
Serotonin
Indolamines
Histidine is the precursor for the neurotransmitter….
That belongs to the group of..
histamine
Indolamines
Glutamine is the precursor for the neurotransmitters….
That belong to the group of…
Glutamate, GABA
Amino acids
Choline is the precursor for the neurotransmitter….
That belongs to the group of..
acetylcholine
‘Other’
Alfa-linoleic acid is the precursor for the neurotransmitter….
That belongs to the group of..
DHA
Endocannabinoids
Serotonin is the … neurotransmitter. What does it cause?
Affected by?
Well-being, happiness
Helps sleep cycle, digestive system regulation
Affected by exercise + light exposure
Dopamine is the … neurotransmitter. What does it cause?
Pleasure
- pleasure, addiction, movement, motivation
Noradrenalin is the … neurotransmitter. What does it cause?
Concentration
- attention, responding actions in brain
- fight & flight response
- contracts blood vessels, increasing blood flow
Adrenalin is the … neurotransmitter. What does it cause?
Fight/flight
- in stressful/exciting situations
- increases heart rate & blood flow
- physical boost, heightened awareness
GABA is the … neurotransmitter. What does it cause?
calming
- calms firing nerves in CNS
- high levels improve focus
- low levels cause anxiety
- contributes to motor contol & vision
Acetylcholine is the … neurotransmitter. What does it cause?
Learning
- thought, learning, memory
- activates muscle action
- attention and awakening
Glutamate is the … neurotransmitter. What does it cause?
memory
- most common neurotransmitter
- learning & memory
- development & creation of nerve contacts
Endorphins = the … neurotransmitter. What does it cause?
euphoria
- during exercise, excitement, sex
- well-being, reducing pain
