Schizophrenia

Question 1

What does the dopamine hypothesis of schizophrenia propose as the pathway of positive symptoms?

Answer 1

Hyperactive (increased secretion) of dopamine in the mesolimbic dopamine pathway leads to positive symptoms of psychosis.

Question 2

What does the dopamine hypothesis of schizophrenia propose as the pathway of negative symptoms?

Answer 2

Hypoactive mesolimbic dopamine pathway leads to negative symptoms of psychosis, cognitive symptoms, and affective symptoms.

Question 3

What is the proposed cause of psychosis?

Answer 3

A neurodevelopmental deviation between the GABA and glutamine neurons in the cortex, specifically a hypofunctional or degenerated NMDA glutamate synapse in schizophrenia. Glutamate hyperactivity then causes key GABA interneurons to inhibit DA release.

Question 4

What symptoms do D2 antagonists target?

Answer 4

Positive symptoms, but can worsen negative symptoms and cause hyperprolactinemia, motor side effects, etc.

Question 5

Pre-synaptic vs. post synaptic receptors

Answer 5

stimulating pre-synaptic receptors may cause the release of neurotransmitters, whereas stimulating post synaptic receptors causes the inhibition (lack of release or turning off of the cell) of neurotransmitter effect

Question 6

What effect would muscarinic 4 receptor agonism have on presynaptic Ach receptors in the hindbrain?

Answer 6

It would shut off activation of mesolimbic dopamine neurons, thus reducing positive symptoms.

Question 7

what is a PAM? (positive allosteric modulator)

Answer 7

Examples include Z hypnotic sleep drugs and benzodiazepines, they are positive allosteric modulators of the GABA receptor