Biopsychology Lesson 3 - Synaptic Transmission

Question 1

What is action potential?

Answer 1

The electrical impulses that neurons transmit

Question 2

What is the pre-synaptic neuron?

Answer 2

The neuron transferring the action potential

Question 3

What is the post-synaptic neuron?

Answer 3

The neuron receiving the action potential

Question 4

What happens in synaptic transmission?

Answer 4

• action potential reaches the pre-synaptic terminal which triggers the release of neurotransmitters vesicles in the presynaptic membrane
• this is known as exocytosis
• the released neurotransmitter diffuses across the synaptic cleft
• it then binds to specialised post-synaptic receptor sites

Question 5

What is re-uptake?

Answer 5

Synaptic transmission only takes place for a fraction of a second, with the effects terminated by re-uptake

• neurotransmitter is taken back by the vesicles on the presynaptic neuron y are stored for later release
• the quicker the neurotransmitter is taken back, the shirts the effects

Question 6

Why can information only travel in one direction?

Answer 6

The vesicles containing neurotransmitters are only present on the pre-synaptic membrane
The receptors for the neurotransmitters are only present on the post-synaptic membrane
It is the binding of the neurotransmitter to the receptor which enables the information to be transmitted to the next neuron
Diffusion of the neurotransmitters mean they can only go from high to low concentration, so can only travel from the pre-synaptic to the post-synaptic membrane

Question 7

How do psychoactive drugs work?

Answer 7

They work by affecting (increasing or inhibiting) the transmission of neurotransmitters across the synapse

Question 8

What are excitatory neurotransmitters?

Answer 8

Neurotransmitters that cause an ge in the membrane of the post-synaptic neuron resulting in an excitatory post-synaptic potential
Meaning that the post synaptic cell is more likely to fire an impulse

Question 9

What are inhibitory neurotransmitters?

Answer 9

Neurotransmitters that cause an inhibitory post-synaptic potential
Making it less Likert thatvthe neuron will fire an impulse

Question 10

What is summation?

Answer 10

The calculation which determines whether or not the cell will fire an impulse
A neuron can deceive both excitatory and inhibitory post-synaptic potential at the same time
The likelihood that the cell will fire an impulse is determined by adding up the excitatory and inhibitory synaptic input
If the net effect is inhibitory, the neuron will not fire, if the net effect is excitatory the neuron will fire

Question 11

What are GABA?

Answer 11

Neurotransmitters that are purely inhibitory

Neurotransmitters can be excitatory or inhibitory (mist can be both)