Synaptic transmission 2

Where does the action potential begin?

• Cell body

• Dendrites

• Initial segment of axon

• Soma

A famous toxin known as botulinum B is used by aesthetic physicians to remove wrinkles. This works by inhibiting exocytosis of acetylcholine by inhibiting which SNARE protein.

• Syntaxin

• Syanptobrevin

• SNAP 25

• Synaptotagmin

A chemical synapse, as opposed to an electric synapse, :

• Can transmit signals with longer distance

• Can transmit signals with reciprocal direction

• Makes use of actual physical contact to conduct electric signals

• Has no delay in transmission

The neurotransmitter, dopamine, is secreted from:

• Locus ceruleus

• Substantia Nigra

• Spinal cord

• Median raphe of brainstem

The following may cause inhibition of post-synaptic cell EXCEPT:

• Opening of chloride ion channels

• Increase in conductance of potassium ions

• Activation of receptor enzymes that decrease excitatory receptors

• Opening of sodium channels

The following are small molecule, rapidly acting transmitters EXCEPT:

• Serotonin

• Glycine

• Nitric Oxide

• Carnosine

Neurotransmitter can either be excitatory, inhibitory or both. Which neurotransmitter has no excitatory effect?

• Acetylcholine

• Norepinephrine

• Dopamine

• Glycine

Specific ions can be found at different concentrations intracellularly and extracellularly. Which ion is least likely found in the extracellular space?

• Potassium

• Sodium

• Chloride

• Bicarbonate

Physostigmine is a toxin that affects synaptic transmission. Which part of the transmission does it affect?

• The opening of potassium channels

• The release of acetylcholine from vesicles

• The opening of calcium channels that bind to synaptotagmin

• The breakdown of acetylcholine

Which protein is responsible for the disassembly of SNARE complex?

• Alpha Snap

• SNAP 5

• SNAP 20

• Synaptotagmin