Neural AO1

• The neural explanation focuses on role of neurotransmitters and brain structures
• What is serotonin?

  Neurotransmitter that regulates anxiety
• Lower levels of serotonin are associated with mood disorders like depression and OCD
• What is dopamine?

  Neurotransmitter which plays a role in pleasure, reward, and motivation
• Abnormally high levels of dopamine are found in OCD patients
• What are neurotransmitters?

  Chemical messenger passing information between neurons and making the brain function effectively
• SSRIs (antidepressants) which directly increase serotonin are known to reduce OCD symptoms
• Animal study where high doses of dopamine level enhancing drugs induce movements resembling compulsive behaviours
• What are the brain structures involved in OCD?

  Orbitofrontal cortex, basal ganglia and thalamus
• Label the brain structures

  A)Orbitofrontal Cortex

  B)Basal Ganglia

  C)Thalamus
• What does the orbitofrontal cortex do?

  Sends ‘worry’ signals to thalamus through the basal ganglia
• What does the basal ganglia do?

  A brain structure which can suppress worry signals (a filter)
• What happens if the basal ganglia is damaged?

  Fails to suppress minor worry signals and thalamus is alerted all the time.
• If the thalamus is alerted, it sends signals back to the frontal cortex acting as a worry circuit. As a result, high anxiety/distress is repeated
• Dopamine actually creates the anticipation for reward.  If there is greater anticipation for reward, then more rewards can be received.
• Label the brain structures

  A)Orbitofrontal Cortex

  B)Basal Ganglia

  C)Thalamus