Synaptic Transmission

Question 1

Axo-somatic synapse

Answer 1

Synapse between neuron and cell body of another neuron

Question 2

Axo-dendritic synapse

Answer 2

Synapse between neuron and dendrite n

Question 3

Axo-Axonic Synapse

Answer 3

Synapse between nerve and axon of another nerve

Question 4

Approximate thickness of synaptic cleft

Answer 4

50nm

Question 5

Catecholamines

Answer 5

Dopamine
Adrenaline/Noradrenaline

**SOME MORE BUT BE AWARE OF THESE TWO

Question 6

Ionotropic receptors

Answer 6

Ligand-gated ion channels

Question 7

How does an inhibitory ionotropic event work

Answer 7

The inhibitory neurotransmitter (e.g. GABA) binds to an ionotropic receptor and lets Cl- anions into post synaptic neuron to decrease polarity

Question 8

What do IPSP and EPSP stand for

Answer 8

Inhibitory/Excitatory Post Synaptic Potential

Question 9

Summarise an EPSP

Answer 9

Basically a normal action potential that brings Vm nearer to threshold and increases chance of AP firing - multiple EPSPs are needed for one AP out at a post synaptic neuron

**BE VAGUELY AWARE THAT 1000s of NEUROTRANSMITTER RECEPTORS ARE INVOLVED IN AN EPSP

Question 10

Discuss the summation of EPSPs

Answer 10

1000s of synpases are involved causing either temporal and/or spatial summation which is needed to produce an AP

Question 11

Neurotransmitters used centrally and peripherally in EPSP transmission

Answer 11

Centrally: Amino Acid Glutamate (Glu)

Peripherally: Acetylcholine (ACh)

Question 12

Are Cl- ions at greater concentration inside or outside the cell

Answer 12

Greater concentration outside the cell

Question 13

What ion is used in an IPSP

Answer 13

Cl-

Question 14

Discuss the mechanism of an IPSP

Answer 14

Inhibitory neurotransmitter (e.g. GABA) binds to an ionotropic receptor on post synaptic membrane which allows Cl- to rush in, reducing Vm and inhibiting AP transmission

**Acts as a hyperpolariser

Question 15

How can an IPSP affect an action potential

Answer 15

It can either entirely inhibit it or lower the membrane potential a little so there is a slight delay

**Acts as a hyperpolariser

Question 16

IPSP Neurotransmitter molecules in Spinal and Central NS

Answer 16

Spinal: Glycine

Central: GABA

Question 17

Factors that terminate receptor events

Answer 17

Cocaine - Affects Noradrenaline and Dopamine reuptake
Phenelzine - Enzyme Degradation
Paroxetine - Affects Serotonin Reuptake
Sertraline - Serotonin Reuptake

Question 18

Temporal/Spatial Summation of AP

Answer 18

When nerve impulses are close to each other temporally or spatially and cause a stacking effect to increase membrane potential in post synaptic neuron - EPSP