Made in: lit in blue
- Nucleus basalis, lit as the globus pallidus and hypothalamus: Large acetylcholine-making neurons in the substantia innominata of the basal forebrain, under the globus pallidus and beside the front of the hypothalamus; it has no shape here, so the two parts it lies between are lit. [3][1]
- Medial septal nucleus, in the septum (septum of telencephalon): One of the septal nuclei; among its GABA and glutamate cells it has acetylcholine-making (cholinergic) cells. It is not a separate shape, so the whole septum is lit. [4][1]
Sent to: lit in orange
- Hippocampus (medial septal nucleus): A major projection of the medial septal nucleus ends in the hippocampal formation. [4][1]
- Cerebellum (pontomesencephalotegmental complex): Its deep nuclei are reached from the brainstem group; they are not separate shapes here, so the whole cerebellum is lit. [1][5]
- Not lit as a target: the cerebral cortex, the main target of the nucleus basalis. Lighting all of it would hide the deeper targets, so it is left grey; see the cortex lobe by lobe on the lobes page. [1][3]
- Also reached but inside the parts lit in blue, so not lit apart: the hypothalamus (from the laterodorsal tegmental nucleus), the substantia nigra and ventral tegmental area of the midbrain, the globus pallidus, and the locus coeruleus and raphe nuclei in the brainstem. [1][5][6]
The pathways, as the sources name them
- Basal nucleus of Meynert, from the nucleus basalis to the neocortex (not lit; see below). Acts mainly on M1 receptors in the neocortex; basal forebrain cholinergic axons reach almost all layers of the cortex. [1][8] See What part of the brain controls attention?
- Medial septal nucleus, from the medial septal nucleus to the hippocampus. Acts mainly on M1 receptors in the hippocampus and parts of the cerebral cortex. [1][4] See What part of the brain controls memory?
- Basal forebrain, from the basal forebrain (the nucleus basalis, the medial septal nucleus and the diagonal band of Broca) to the neocortex, hippocampus and amygdala. The basal forebrain is considered the major source of the acetylcholine supply to all three. [2]
- Pontomesencephalotegmental complex, from the pedunculopontine and laterodorsal tegmental nuclei to the thalamus, the deep cerebellar nuclei and the lower brainstem. Acts mainly in the brainstem, the deep cerebellar nuclei, the locus coeruleus and raphe nuclei, and also projects to the thalamus, tectum, basal ganglia and basal forebrain. [1] See What part of the brain controls sleep?
Good to know
- A small share of their neighbours: cholinergic neurons are only about 5% of the cells of the basal forebrain. [8]
- Sleep and waking: acetylcholine release in the basal forebrain promotes wakefulness and REM sleep, and the pedunculopontine and laterodorsal tegmental nuclei take part in generating REM sleep. [2][6] See What part of the brain controls sleep?
- Learning: acetylcholine encourages neuronal plasticity, the brain’s way of changing its connections as it learns. [2] See What part of the brain is responsible for learning?
- Outside the brain it is the chemical motor neurons release to make skeletal muscles contract, at the neuromuscular junction, and the main transmitter of the parasympathetic nervous system. [1] See What part of the brain controls movement?
- The first neurotransmitter identified: in 1921 Otto Loewi found that the vagus nerve releases a substance that slows the heart, which he called “Vagusstoff” and which proved to be acetylcholine; he and Henry Dale shared the 1936 Nobel Prize. [1]
What it takes part in
Each lit with every part that takes part: What part of the brain controls attention? · What part of the brain controls memory? · What part of the brain is responsible for learning? · What part of the brain controls sleep? · What part of the brain controls movement?
Where it is made, each on its own page: Nucleus basalis; Medial septal nucleus, in the septum (septum of telencephalon); Pedunculopontine nucleus, in the pons; Laterodorsal tegmental nucleus, in the midbrain.