Information Processing

Question 1

What do inhibitory neurones do?

Answer 1

Release neurotransmitters that HYPERPOLARISE the nerve cell membrane

Question 2

What do excitatory neurones do?

Answer 2

Release neurotransmitters that DEPOLARISE the nerve cell membrane

Question 3

What is the activity of a nerve determined by?

Answer 3

balance of inhibitory and excitatory input

Question 4

What is a disadvantage of EPSPs (excitatory post synaptic potentials) and how is this overcome?

Answer 4

• single EPSPs may be too small to depolarise the membrane to threshold
• so EPSPs can combine (summate) to achieve a threshold depolarisation

Question 5

What are 2 ways EPSPs summate?

Answer 5

• TEMPORAL SUMMATION
  multiple EPSPs in rapid succession from a single synapse
• SPATIAL SUMMATION
  simultaneous multiple EPSPs from different synapses

Question 6

Give a summary on neuronal physiology

Answer 6

Resting membrane potential:
- the transmembrane potential of the resting cell

Graded potential:
- temporary, localised change in the resting potential
- amplitude signal caused by a stimulus

Action potential:
- an electrical impulse and a frequency signal produced by a GP that exceeds a threshold
- propagates along the surface of an axon to the nerve terminal and synapse

Synaptic activity:
- releases neurotransmitters from the presynaptic membrane
- produces GPs in the postsynaptic membrane

Information processing:
- response (integration of stimuli) of the postsynaptic cell