<Ul> <Li> Periaqueductal gray : The area of gray matter around the cerebral aqueduct , which contains various neurons involved in the pain desensitization pathway . Neurons synapse here and , when stimulated , cause activation of neurons in the nucleus raphe magnus , which then project down into the posterior grey column of the spinal cord and prevent pain sensation transmission . </Li> <Li> Oculomotor nerve nucleus : This is the third cranial nerve nucleus . </Li> <Li> Trochlear nerve nucleus : This is the fourth cranial nerve . </Li> <Li> Red nucleus : This is a motor nucleus that sends a descending tract to the lower motor neurons . </Li> <Li> 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 . </Li> <Li> 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 reflexes . </Li> <Li> 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 . </Li> <Li> Ventral tegmental area : A dopaminergic nucleus located close to the midline on the floor of the midbrain . </Li> <Li> Rostromedial tegmental nucleus : A GABAergic nucleus located adjacent to the ventral tegmental area . </Li> </Ul>
<Ul> <Li> Periaqueductal gray : The area of gray matter around the cerebral aqueduct , which contains various neurons involved in the pain desensitization pathway . Neurons synapse here and , when stimulated , cause activation of neurons in the nucleus raphe magnus , which then project down into the posterior grey column of the spinal cord and prevent pain sensation transmission . </Li> <Li> Oculomotor nerve nucleus : This is the third cranial nerve nucleus . </Li> <Li> Trochlear nerve nucleus : This is the fourth cranial nerve . </Li> <Li> Red nucleus : This is a motor nucleus that sends a descending tract to the lower motor neurons . </Li> <Li> 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 . </Li> <Li> 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 reflexes . </Li> <Li> 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 . </Li> <Li> Ventral tegmental area : A dopaminergic nucleus located close to the midline on the floor of the midbrain . </Li> <Li> Rostromedial tegmental nucleus : A GABAergic nucleus located adjacent to the ventral tegmental area . </Li> </Ul>
which structure of the brain stem is primarily related to alertness
which structure of the brain stem is primarily related to alertness
Reticular formation
Reticular formation