L22

Question 1

explain neurodegeneration, what illnesses its linked to, and how it could be controlled

Answer 1

• Resulting from excessive glutamate/ Ca+
  
  • NMDA receptors involved
  • Linked to
    ○ Ischemia
    ○ Traumatic brain injuries
    ○ Alzheimer’s disease
    ○ MNDS
  • Controlling it
    ○ Retard neuronal death in the affected areas
    Glutamate receptor antagonists + inhibitors downstream of receptor activation

Question 2

explain alzheimers disease

Answer 2

• Cholinergic (means uses Ach as neurotransmitter) neurons in basal forebrain nucleus + hippocampus degenerate
  
  • Cholinergic terminals in cortex lost
  • (obvious solution is the increase Ach neurotransmitters in brain, used before, doesn’t work)
• Brain shrinks- plaques + tangles block communication between brain cells
  
  • Progressively lose memory + cognitive function
  • Inability to carry out activities + daily living
• Acetylcholinesterase inhibitors + memantine (is a NMDA receptor antagonist, stops glutamate from binding, stopping Ca+ entering) the only drugs approved for treating Alzheimer’s disease

Question 3

define plaques and intraneuronal

Answer 3

○ Plaques
§ Extracellular morphous extracellular deposits of beta amyloid protein
○ Intraneuronal
neurofibrillary tangles, comprising filaments of a phosphorylated form of microtubule associated protein

Question 4

explain cholinergic neurons

Answer 4

• Neurons that use Ach as neurotransmitter
  
  • Found in brain
  • Control cognitive, arousal, memory, motor control, learning
    In peripheral, involved with voluntary control of movement + autonomic nervous system

Question 5

explain the breakdown of acetylcholine

Answer 5

• Ach broken down to acetate + choline by Ach esterase, so choline recycled

Question 6

explain the poisoning via acetylcholinesterase inhibitor

Answer 6

• Leads to accumulation of Ach in the synaptic cleft, resulting in over stimulation of nicotine + muscarinic Ach receptors and impeded neurotransmission
  Typical symptoms are agitation, muscle weakness, hypersalivation, sweating

Question 7

explain ALS

Answer 7

• Most common motor neuron disease is ALS (amyotrophic lateral sclerosis)
  ○ More common in males
  ○ Appears after 50yrs
  ○ Affects both upper + lower motor neurons
  § Neurons in brain + spinal cord
  § Which affect muscles of arms, legs, mouth, respiratory system
  § Symptoms- weight loss, slurred speech, difficulty breathing
  Patients live for 3-5yrs after diagnosis, with care could be 10+ yrs

Question 8

explain the motor response from the LMN

Answer 8

• Provides input to lower motor neurons
  1. Local circuit neurons
  2. Upper motor neurons
  3. Basal nuclei neurons
  Cerebellar neurons