Key Processes

Question 1

Synaptic Transmission

Answer 1

1- chemical process using neurotransmitters (NT)

2 - action potential reaches end of neuron - triggers release of neurotransmitters from vesicle sacs

3- NT diffuse across synaptic cleft & fit into matching receptors on postsynaptic neuron

4- left over NT reabsorbed into synaptic neuron through transporters (re uptake)

Question 2

Action Potential

Answer 2

• resting state, cell is negatively charged
• when neuron is activated, cell becomes positive (depolarisation) and creates an electrical impulse
• travels to terminal buttons
• Action potential only generated if it reaches a certain threshold (-55mV)
• All or nothing event

Question 3

Recreational drugs - Nicotine

Answer 3

• mimics neurotransmitter - (acetylcholine) and nicotine attaches to receptors
• This excites the neuron, causing action potential to fire and dopamine released
• Binding over time affects the receptors and causes a decrease and a change in cell shape
• So, more dopamine needed for same effect
• Desensitisation - more substance required for same effect
• Causes addition - nicotine needed to maintain normal functioning

Question 4

Recreational drugs - Cocaine

Answer 4

• blocks dopamine re-uptake receptors
• stops re-uptake into presynaptic neuron
• excess dopamine causes over-stimulation- over-stimulation causes euphoria
• over-stimulation = desensitisation

Question 5

Neurotransmitter - Serotonin

Answer 5

• Serotonin usually reduces aggression by preventing stimulation if the amygdala (structure in limbic)
• Stimulation of amygdala increases aggressive behaviour
• Low levels of serotonin = less inhibition of the amygdala
• As a result, becomes more active when stimulated by external events, causing person to act on impulses and make aggression more likely

Question 6

Neurotransmitter - Dopamine

Answer 6

• increased dopamine levels can produce increased levels of behaviour

Question 7

Reward pathway

Answer 7

Pathway within the limbic system that is associated with feelings of reward in day-to-day life and the feelings of pleasure that lead to craving and addition. Activation of this pathway by addictive drugs leads to increase levels of dopamine.

Question 8

How hormones work

Answer 8

• binding to receptor proteins in target cells and changing cell function
• hormone secretion can be triggered by other hormones or by activity at neuronal level

Question 9

Cortisol & Aggression

Answer 9

• main job is managing stress levels and also inhibits aggression
• lower cortisol levels = more aggression as there is an attempt to create more stressful situations so more cortisol is released and the ANS is stimulated

Question 10

Testosterone & Aggression

Answer 10

• generally accepted that men are more aggressive than women, it could be that aggression is at least in part the result of the hormone testosterone