L3 - Synaptic Transmission

Question 1

What are action potentials?

Answer 1

Electrical impulses transmitted from neurons between the pre-synaptic neuron and ty spots-synaptic neuron

Question 2

What happens when the action potential reaches the pre-synaptic terminal?

Answer 2

• Triggers release of neurotransmitters from sacs on the pre synaptic membrane ( vesicles in exocytosis)
• neurotransmitter diffuses across the synaptic cleft and binds to specialised post synaptic receptor sites

Question 3

What is reuptake?

Answer 3

When the neurotransmitter is taken back by the vesicles on the pre-synaptic neuron so they are stored for release. The quicker it is taken back, the shorter the effects.

Question 4

What direction does information travel?

Answer 4

• in One direction at a synapse
• vesicles are only present on the pre-synaptic membrane
• receptors for neurotransmitter is only available on the post-synaptic membrane
• the binding of the receptor and neurotransmitter is what transmits the info
• Diffusion = high to low conc, so only travels from pre-synaptic to post- synaptic

Question 5

How do Psychoactive drugs work?

Answer 5

• affecting the transmission of neurotransmitters across the synapse

Question 6

What are excitatory neurotransmitters?

Answer 6

• Causes an electrical charge in the membrane of the post synaptic neuron
• Causing an excitatory post synaptic potential
• Making the cell more likely to fire an impulse

Question 7

What are inhibitory neurotransmitters?

Answer 7

• cause an inhibitory post-synaptic potential

- less likely that neuron will fire impulse

Question 8

What is summation?

Answer 8

• Neurons receive ISSPs and EPSPs at the same time
• Likelihood of cell firing impulse is adding the excitatory/inhibitory synaptic input
• The net of the calculation is the summation and decides whether the cell will fire