All diagrams in context and arousal
Histamine and orexin arousal modules
Histamine and orexin are distinct systems with interacting arousal roles. Neither system supplies a one-to-one map to an ADHD symptom.
Histamine and orexin arousal modules
Scoped educational mechanism
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Read the diagram explanation and sources
Histamine is a monoamine, while orexin/hypocretin molecules are peptides. Rodent experiments distinguish their roles in wakefulness and demonstrate orexin excitation of histamine neurons. Both operate in wider interacting arousal systems. The schematic separates origins, transmitters and evidence scope; it is not a complete anatomical map, evidence of a deficit in the reader or a rationale for an ADHD medicine or supplement.
- Histamine neurons → Histamine signalling: histamine
- Histamine signalling → Broad arousal context: modulation
- Orexin neurons → Orexin signalling: orexin
- Orexin signalling → Histamine signalling: interaction
What the diagram shows
Histamine is a monoamine, while orexin/hypocretin molecules are peptides. Rodent experiments distinguish their roles in wakefulness and demonstrate orexin excitation of histamine neurons. Both operate in wider interacting arousal systems. The schematic separates origins, transmitters and evidence scope; it is not a complete anatomical map, evidence of a deficit in the reader or a rationale for an ADHD medicine or supplement.