Lecture 5: Synaptic Transmission Flashcards Preview

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Flashcards in Lecture 5: Synaptic Transmission Deck (7):

What are the differences between an electrical synapse and a chemical one?

Electrical synapses transfer signals via gap junction, whereby a protein gaps the junction between nerve cells, whereas in a chemical synapse, the release of neurotransmitters into the synaptic cleft forms the bases of interneuronal communication.


Name the two main groups of neurotransmitter, describe them and give some examples.

(1) Classical Neurotransmitters: biogenic amines (e.g. acetylcholine, dopamine, serotonine), amino acids (e.g. GABA, Glutamate) or nucleotides (e.g. Adenosine, ATP).

(2) Peptides: more complex molecule types; chains of aminoacids (if more than 100, it's a protein); depending on where they are found in the body, they can be either neurotransmitters or hormones. Examples are oxytocin, insuline.


What is the main difference between noradrenergic and dopaminergic neurons?

In noradrenergic neurons there is an additional enzyme that transforms tyrosine into L-Dopa.


Which neurotransmitter is mainly excitatory and which one is mainly inhibitory in the CNS?

Glutamate is the main excitatory transmitter, while GABA is the main inhibitory transmitter.


Name respectively two examples of neurotransmitters involved in fast point-to-point signaling and slow regulatory signaling.

Fast: acetylcholine (nicotinic!) and glutamate.

Slow: neuropeptides, monoamines (e.g. dopamine).


Name the four major groups of receptors, their main features and / or respectively an example.

(1) Ligand-gated ion channels (e.g. nicotinic); timescale: milliseconds
(2) G-protein coupled receptors (e.g. muscarinic); slower, timescale: seconds
(3) Kinase-linked receptors (e.g. cytokine); related to phosphor; slower, timescale: hours
(4) Nuclear receptors (e.g. oestrogen); modify gene transcription; slowest, timescale: hours


How many dopamine receptors are discovered so far? Which are inhibitory and which are excitatory?

There are five discovered (D1-D5), with D1 and D5 being excitatory and D2 being inhibitory. The remaining receptors are not defined yet.