Synapses

Question 1

What are synapses?

Answer 1

Where neurons pass on signals to other neurons or to muscle cells

Question 2

What are the names of the neurons that send and receive the message?

Answer 2

Send= pre synaptic 
Receive= post synaptic

Question 3

What is the postsynaptic potential (PSP)?

Answer 3

The electrical response the post-synapse makes in response to neurotransmitter from the pre-synapse

Question 4

What are the vesicles filled with and give an example?

Answer 4

Neurotransmitters e.g acetylcholine

Question 5

What experiment did Llinas and Nicholson (1975) carry out and find?

Answer 5

Injected glowing protein aequorin from a jellyfish into synapse

Found light emitted by pre synaptic neuron was proportional to PSP size

Question 6

What triggers calcium channels to open?

Answer 6

The change in membrane voltage

Question 7

Give an example of a non spiking neuron

Answer 7

Neurons in the retina

Question 8

How long is the delay for a signal to be passed on to another neuron and what causes this delay?

Answer 8

0.5ms

Calcium channels opening (transmitter diffusion doesn’t account for much time)

Question 9

How does neurotransmitter cause a PSP?

Answer 9

Transmitter binds to a receptor site causing the chemically gated ion channels to open

Some excite and some inhibit neuron

Question 10

Give an experiment as evidence for neurotransmitter release

Answer 10

Neher and Sakmann on a frog synapse
Measured current flow through a single post synaptic ion channel using patch clamping
Measured the opening and closing of the channel

Question 11

Give some differences between spikes and psps

Answer 11

Spike:
VG channels, 1/10V, discrete and fixed amplitude, travel by propagation

PSP:
Chemical gated channels, generally few mob, adds with other psps, cannot travel far

Question 12

What is integration?

Answer 12

When a neuron combines the different PSP’s it receives, enabling the nervous system to make decisions