Table 2.
Overview of neurotransmitters, their receptors, brain areas, and associated fatigue-related behaviors.
| Neurotransmitter | Primarily excitatory or inhibitory | Receptors | Brain areas | Fatigue-related behaviors |
|---|---|---|---|---|
| GABA | - Inhibitory | - GABAA - GABAB |
- Dorsal raphe nucleus - Lateral hypothalamus - Locus coeruleus - Periaqueductal gray area |
- Arousal - Motivation - Sleep/wake -Sleepiness |
| Serotonin | - Inhibitory | - 5-HT receptors | - Dorsal raphe nucleus | - Arousal - Anxiety - Depression -Sleep/wake |
| Norepinephrine | - Excitatory | - Alpha-adrenergic receptors - Beta-adrenergic receptors |
- Caudal ventral medulla - Nucleus tractus solitarius |
- Anxiety - Attention - Depression - Motivation -Wakefulness |
| Dopamine | - Excitatory | - D1-like receptors - D2-like receptors |
- Arcuate nucleus - Periventricular nucleus - Posterior hypothalamus - Subtantia nigra - Ventral tegmental area - Zona incerta |
- Anxiety - Arousal - Depression - Motivation -Sleep/wake |
| Histamine | - Excitatory | - Histamine 1 receptors - Histamine 2 receptors - Histamine 3 receptors - Histamine 4 receptors |
- Tuberomammillary nucleus | - Arousal - Mood - Sleep/wake |
| Glutamate | - Excitatory | - AMPA receptors - Kainite Receptors NMDA receptors |
- Cerebellum - Cerebral cortex - Hippocampus - Parabrachial nucleus |
- Attention - Cognition - Depression - Sleep/wake - Tiredness |
| Acetylcholine | - Excitatory | - Muscarinic acetylcholine receptors - Nicotinic acetylcholine receptors |
- Basal forebrain - Cerebral cortex - Laterodorsal tegmental nuclei - Pedunculopontine nucleus |
- Arousal - Cognition - Memory - Sleep/wake |
| Orexin | - Excitatory | - Orexin 1 receptors - Orexin 2 receptors |
- Lateral hypothalamus - Perifornical area |
- Arousal - Energy homeostasis - Sleep/wake |