All diagrams in synapses and receptor signalling
Synaptic clearance and intracellular metabolism
Transport out of the cleft and intracellular breakdown are different routes. MAO is not an enzyme floating freely in the synaptic cleft.
Synaptic clearance and intracellular metabolism
Scoped educational mechanism
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Clearance from the extracellular space includes diffusion and transporter-mediated uptake. DAT is important in many dopamine regions; NET can also clear dopamine where DAT expression is low, including evidence from mouse prefrontal cortex. Intracellular dopamine can be re-stored or metabolised. MAO is associated with the outer mitochondrial membrane; its aldehyde products require further processing. COMT-dependent methylation is another route whose importance differs by cell and region. This concerns transmitter handling, not systemic metabolism of an ADHD medicine.
- Extracellular dopamine → DAT uptake: reuptake
- DAT uptake → Cytosolic dopamine: transport
- Cytosolic dopamine → Vesicular storage: VMAT2
- Cytosolic dopamine → MAO pathway: metabolism
- Cytosolic dopamine → COMT pathway: metabolism
What the diagram shows
Clearance from the extracellular space includes diffusion and transporter-mediated uptake. DAT is important in many dopamine regions; NET can also clear dopamine where DAT expression is low, including evidence from mouse prefrontal cortex. Intracellular dopamine can be re-stored or metabolised. MAO is associated with the outer mitochondrial membrane; its aldehyde products require further processing. COMT-dependent methylation is another route whose importance differs by cell and region. This concerns transmitter handling, not systemic metabolism of an ADHD medicine.