CNS & Neurotransmitters in Human Behaviour

Question 1

Outline 6 points about neurotransmitters in human behaviour

Answer 1

• NT’s are chemical messengers that act between neurons in the brain
• Inhibitory = prevents generation of action potential
• Excitatory = promotes generation of action potential
• Serotonin - stabilises our mood and feelings, low levels = aggression
• Dopamine - pleasure feelings, addiction, high levels = aggression
• Action potential = aspike in electric charge in an axon caused by ion
  Synaptic transmission
• When action potential reaches the presynaptic terminal buttons, it triggers the release of neurotransmitters from the vesicles
• When the neurotransmitters diffuse across the synaptic cleft, they fit into matching receptors on the dendrites of the postsynaptic neuron
• Reuptake can occur

Question 2

Give a strength of the NT and transmission at the synapse approach

Answer 2

P- Methods have scientific credibility
E- Human brain scanning increasingly used in research, producing actual brain activity and structures at work
E- Reliable, more than 1 person can analyse scans to check results

Question 3

Give a piece of opposing research of the NT and transmission at the synapse approach

Answer 3

P- Allen and Stevens (1994)
E- Found synaptic transmission regarding hippocampal neurons unreliable, with less than 1/2 the NTs being picked up by postsynaptic neuron
E- Might not be evidence that synaptic transmission is not involved in messaging in the brain, it might just mean it isn’t as straightforward as it seems

Question 4

Give a piece of supporting research of the NT and transmission at the synapse approach

Answer 4

P- Jovanovic (2008)
E- PET scans to look at serotonin system of women. Women were used as low serotonin levels are linked to depression more in women. Part of her study looked at women with PMDD to see if they showed differences in serotonin system when compared to a control group. Scanning was done before and after ovulation. The control showed differences in synaptic receptors
E- Suggests synaptic receptors have a role in PMDD. This is evidence that synaptic transmission, involving serotonin, relates to mood, e.g. depression

Question 5

Give a weakness of the NT and transmission at the synapse approach

Answer 5

P- Most evidence from studies using animals, where lesions can be made
E- Human brains involve consciousness and emotional functioning, different to animals
E- Findings may not be generalisable to human brains