Depression Flashcards
What does the mesocorticolimbic dopamine system control?
Motivation circuit.
What 4 structures are in the limbic brain?
Basal ganglia
cingulate gyrus
Hippocampus
Amygdala
What is the physiological association of major depressive disorder? (deficiencies vs enhanced)
Increased engagement of limbic regions but decreased engagement of striatum/basal ganglia.
What is the amine hypothesis of depression?
Monoaminergic NT have similar and overlapping synthesis pathways, dysfunction in pathway leads to:
Fewer NT release, fewer receptors, impaired transduction.
What is reserpine?
Drug that depleted neurons of dopamine and NE, causes depression.
What is iproniazid?
Drug that alleviated depression by inhibiting MAO (monoaminergic oxidase enzyme)
What are the three issues with the amine hypothesis?
- Only moderately effective.
- Inconclusive evidence that serotonin and NA play a part in depression.
- Takes weeks for clinical effects to set in despite there being an immediate effect physiologically.
What is the glutamatergic hypothesis?
Depression is associated with reducion in glutamate signalling in the cortex, leading to impacts in gene transcription, long-term potentiation, and synapse formation impairments.
What are monoamine antidepressants?
Function to alleviate depression by increasing synaptic levels of monoamine NT. Can either block MAO or block selective reuptakers.
Why is cheese avoided when taking MAO inhibitors?
Cheese containing dietary tyramine (mimics NA) may cause adverse increases of NA concentration in the blood, leading to hyper tension by NA binding to beta-adrenergic receptors in the heart.
What are SSRIs?
Selective serotonin reuptake inhibitors.
What are SNRIs?
Selective serotonin and nore=adrenaline reuptake inhibitors.
Why are SSRIs, SNRIs, and MAOIS somewhat dangerous?
Non-specific and cause off-target effects.
What is ketamine?
Glutamate antidepressant that binds non-competitively to NMDA receptors antagonistically, causing a surge of glutamate in the cell. The burst resets GABA and glutamate systems, alleviates depression with a single IV administration.
What are new agents in anti-depressant medication research?
Drugs that target downstream effects like secondary messengers (cAMP).
