Neurotransmitters and brain function.

4 lobes of the brain

• frontal lobes - front part - thinking, speaking, memory, movement

• Temporal lobe - side part - hearing

• parietal lobe - top part of brain - touch, language, taste, smell

• Occipital lobe - back part of brain- vision, colour.

Excitatory Neurotransmitters

The neurotransmitters increase the likelihood that postsynaptic neuron will fire an action potential. Make the inside of the postsynaptic neuron more positive (depolarised)

Inhibitory Neurotransmitters

These neurotransmitters decrease the likelihood that the postsynaptic neuron will fire an action potential.

Make the inside of the postsynaptic neuron more negative (hyperpolarised).

Neurotransmitters- functions + associated disorders

GABA (Gamma- Aminbutryic Acid)

Function: Major inhibitory neurotransmitter, reducing neuronal excitability

Associated disorders: anxiety disorders, epilepsy

Acetycholine

Functions: muscle activation, learning, memory

Associated Disorders : Alzheimer’s disease

Serotonin

Functions: mood regulation, sleep, appetite and social behaviour.

Associated disorders: Depression, ADHD

Norpinphrine

Functions: attention, arousal and stress response

Associated Disorders: Depression, ADHD

Dopamine

Function: reward, motivation, motor control, cognitive

Associated disorders: Parkinson’s disease, schizophrenia, addiction

Glutamate

Functions: major excitatory neurotransmitter, involved in learning and memory

Associated disorders: stroke damage, schizophrenia

Impacts of seretonin on behaviour

• mood regulation - helps maintain mood balance

• low levels - associated with mood disorders

• low levels of serotonin are linked to increased aggression + impulsive behaviour.

case study supporting low levels of seretonin affects - anti social

SCERBOT RAINE (1993) - low seretonin = anti social behaviour

• conducted a metal analysis on 29 pieces of research into anti-social adults + children finding in all cases, low levels of seretonin.

case study link between low levels serotonin and aggression

MOIR + JESSEL (1995) - low levsl of seretonin = aggression

• cited a number of human + animal studies which suggest a link between low levels of seretonin + aggression, which is linked criminally behaviour.

How to boost seretonin levels ?

• sleep

• healthy diet

• exercise

• meditation

• sun

Dopamine imbalances

dopamine imbalance can contribute to impulsivity ans aggressive behaviour

Reward system + reinforcement learning

dopmaine release during rewarding experiences reinforces behaviour, promoting learning. + adaptation.

dopmine case study linking to criminal behaviour

Couppis (2008)

• argues that some individuals who take part in certain criminal behaviours may experience an increase in dopamine + result in seeking out such experiences again due to rewarding feeling

case study refering to dopamine , aggressive behaviour

Buitelaar (2003)

• Found that the juvenile delinquents who were givem dompamine antagonists which reduce levels of dopamine, showed a decrease in aggressive behaviour.

• supports the idea that low dopamine = less aggression

Alcohol and behaviour

• victims perceived the offenders to be under the influence of alcohol in 53% of violent incidents.

• 70% of violent incident which took place in public, was in alcohol related spaces

• ^^ according to national statistics CSEW

What is amphetamine ?

A sympathomimetic drug that is used as a street drug + as a medication to control symptoms of narcolepsy.

Amphetamine + behaviour

• hostility + aggressiveness

• Auditory / visual hallucinations

• loss of inhibitations → lead to risky behaviour

• impared judgemenf → can lead to accidents