Biological Basis of Nervous System Disorders 7.3 [HY]

Question 1

Causes of Schizophrenia

Answer 1

• causes are genetic, but trauma at birth, especially hypoxemia (low oxygen concentrations in the blood), is also considered to be a risk factor
• excessive marijuana use in adolescence is associated with increased risk.
• highly associated with an
  excess of dopamine in the brain
• many medications used to treat schizophrenia, such as neuroleptics, block dopamine receptors.
• neuroleptic known as antipsychotics : medications depress nerve function.

Question 2

Somatic (Body) Markers associated with Depression

Answer 2

• Abnormally high glucose metabolism in the amygdala
• Hippocampal atrophy after a long duration of illness
• Abnormally high levels of glucocorticoids (cortisol)
• Decreased norepinephrine, serotonin, and dopamine (monoamine theory of depression)
• found that both these neurotransmitters and their metabolites are decreased in depressed patients, meaning that their actual production is
  decreased

Question 3

Somatic (Body) Markers associated with Bipolar Disorders

Answer 3

• Increased norepinephrine and serotonin (monoamine theory)
• Higher risk if parent has bipolar disorder
• Higher risk for persons with multiple sclerosis

Question 4

Alzheimer’s Disease

Answer 4

• type of dementia characterized by gradual memory loss, disorientation to time and place, problems with abstract thought, and a tendency to misplace things
• changes in mood or behavior, changes in personality, difficulty with procedural memory, poor judgment, and loss of initiative.
• Family history is a significant risk factor and, lower risk of developing the disease with higher levels of education.
• mutations in the presenilin genes on chromosomes 1 and 14 contribute to having the disease, and mutations in the apolipoprotein E gene on chromosome 19 can also
  alter the likelihood of acquiring the disease
• β-amyloid precursor protein gene on chromosome 21 is known to contribute to Alzheimer’s disease, explaining the much higher risk of Alzheimer’s in individuals with Down syndrome.

Question 5

Somatic Symptoms of Alzheimer’s Disease

Answer 5

• Diffuse atrophy of the brain on CT or MRI
• Flattened sulci in the cerebral cortex
• Enlarged cerebral ventricles
• Deficient blood flow in parietal lobes, which is correlated with cognitive
  decline
• Reduction in levels of acetylcholine
• Reduction in choline acetyltransferase (ChAT), the enzyme that produces acetylcholine
• Reduced metabolism in temporal and parietal lobes
• Senile plaques of β-amyloid (a misfolded protein in β-pleated sheet form)
• Neurofibrillary tangles of hyperphosphorylated tau protein

Question 6

Parkinson’s Disease Symptoms

Answer 6

• Characterized by
  {bradykinesia: slowness in movement}
  {resting tremor: a tremor that appears when muscles are not being used}
  {pill-rolling tremor: flexing and extending the fingers while moving the thumb back and forth, as if rolling something in the fingers}
  {masklike facies: static and expressionless facial
  features, staring eyes, and a partially open mouth}
  {cogwheel rigidity: muscle tension that intermittently halts movement as an examiner attempts to manipulate a limb}
  {shuffling gait}
  {stooped posture}
  {Depression}
  {Dementia}

Question 7

Parkinson’s Disease (Biological bases)

Answer 7

• decreased dopamine production in the substantia nigra, a layer of cells in the brain that functions to produce dopamine to permit proper functioning of the basal ganglia
• Basal Ganglia is critical for initiating and terminating movements, as well as sustaining repetitive motor tasks and smoothening motions
• the symptoms of Parkinson’s disease flow logically from its underlying cause.