Editing Brainstem (section)

====Midbrain nuclei====
The midbrain consists of:
*[[Periaqueductal gray]]:  The [[gray matter]] around the [[cerebral aqueduct]] contains neurons involved in the [[pain]] desensitization pathway.  Neurons synapse here. When stimulated by a signal, the synaptic connections activate neurons in the [[nucleus raphe magnus]]. The pathway then projects down into the [[posterior grey column]] of the spinal cord, inhibiting pain sensation transmission.
*[[Oculomotor nerve]] nucleus:  This is the third [[cranial nerve nucleus]].
*[[Trochlear nerve]] nucleus:  This is the fourth cranial nerve.
*[[Red nucleus]]: This is a motor nucleus that sends a descending tract to the [[lower motor neuron]]s.
*[[Substantia nigra pars compacta]]: This is a concentration of neurons in the ventral portion of the midbrain that uses [[dopamine]] as its [[neurotransmitter]] and is involved in both motor function and emotion. Its dysfunction is implicated in [[Parkinson's disease]].
*[[Reticular formation]]: This is a large area in the [[midbrain]] that is involved in various important functions of the midbrain. In particular, it contains lower motor neurons, is involved in the pain desensitization pathway, is involved in the arousal and consciousness systems, and contains the [[locus coeruleus]], which is involved in intensive [[alertness]] modulation and in [[Autonomic nervous system|autonomic]] reflexes.
*[[Central tegmental tract]]: Directly anterior to the floor of the [[fourth ventricle]], this is a pathway by which many tracts project up to the cortex and down to the spinal cord.
*[[Ventral tegmental area]]: A [[dopaminergic]] [[nucleus (neuroanatomy)|nucleus]], known as [[Dopaminergic cell groups#Cell group A10|group A10 cells]]<ref name="Hegarty">{{cite journal |last1=Hegarty |first1=SV |last2=Sullivan |first2=AM |last3=O'Keeffe |first3=GW |title=Midbrain dopaminergic neurons: a review of the molecular circuitry that regulates their development. |journal=Developmental Biology |date=15 July 2013 |volume=379 |issue=2 |pages=123–38 |doi=10.1016/j.ydbio.2013.04.014 |pmid=23603197|doi-access=free }}</ref> is located close to the midline on the floor of the midbrain.
*[[Rostromedial tegmental nucleus]]: A [[GABAergic]] nucleus located adjacent to the ventral tegmental area.

<gallery>

Midbrain - superior colliculus.svg|Cross-section of the midbrain at the level of the superior colliculus
Midbrain - inferior colliculus.svg|Cross-section of the midbrain at the level of the inferior colliculus
</gallery>