brain chemicals+disease

• IMBALANCE OF NEUROTRANSMITTERS IN BRAIN:

  • parkinsons disease
  • depression
• parkinsons disease

  • brain disorder which affects coordination of movement, caused by loss of neurones in the brain
• symptoms of parkinsons

  • tremors in body parts
  • slow movement
  • stiff/inflexible muscles
  • difficulties with balance
  • changes to speech
• parkinsons cause

  • lost neurones produce dopamine(involved in muscle control)

  1)less dopamine is released and less binding to receptors

  2)fewer NA+ channels on membrane opened so depolarisation of post neurone does not occur

  3)leads to fewer action potentials-creating symptoms eg tremors
• treatment of parkinsons

  • dopamine agonist=produce same effect as dopamine, bind to and activate dopamine receptors
  • dopamine precursors=chemicals that can be converted into dopamine in the neurones eg L-dopa
  • enzyme inhibitors=MAOB inhibitors inhibit activity of enzymes that normal break down dopamine in synaptic cleft-increased levels of dopamine in brain
  • gene therapy=addition of genes to affected cells in pbrain to increase dopamine production and prevent distruction of dopamine producing cells
• depression

  • low moods and low energy
  • caused by low levels of serotonin(sometimes noradrenaline and dopamine)
  • serotonin transmits nerve impulses through areas of brain that control mood
• treatment of depression

  • SSRIs=prevent reuptake of serotonin by presynaptic membrane in synapses, increases overall levels of serotonin in the brain
  • TCA's=increase levels of serotonin and noradrenaline in brain
  • MAOB inhibitors=inhibit enzymes that would break down neurotransmitters in synaptic cleft in brain