Pons

Anatomy

• The middle part of the brainstem. Ventral basilar part: pontine nuclei and transverse fibers → middle cerebellar peduncle.
• Dorsal tegmentum: locus coeruleus (noradrenaline), raphe nuclei (serotonin), pontine reticular formation, cholinergic PPN/LDT (REM).
• Nuclei of cranial nerves V, VI, VII and VIII; medial longitudinal fasciculus (MLF).
• Blood supply: basilar artery (paramedian and circumferential branches), AICA.

Functions

• Corticopontocerebellar pathway: relays motor plans from the cortex to the cerebellum.
• Locus coeruleus: arousal, attention (an inverted-U relationship with performance), stress response.
• Raphe: serotonergic regulation of mood, impulsivity, sleep and appetite.
• REM sleep and REM atonia; sleep–wake transitions.
• Facial sensation and chewing (V), facial expression (VII), hearing and balance (VIII), lateral gaze (VI), adjustment of breathing rhythm.

Connections and chemistry

• Locus coeruleus → whole cortex, hippocampus, amygdala, thalamus (noradrenaline)
• Raphe → cortex, limbic system, striatum (serotonin)
• Pontine nuclei → cerebellum
• PPN/LDT → thalamus (acetylcholine)

Development

Developmental course through childhood and adolescence.

• REM sleep makes up about half of total sleep in the newborn and decreases in childhood.
• The ABR is an index of brainstem maturation in preterm infants.
• Serotonin also acts as a neurotrophic signal in early brain development.

Clinical

• Anxiety and panic: LC hyperactivity. PTSD: hyperarousal, nightmares (the α1 antagonist prazosin, α2 agonists).
• ADHD: noradrenergic treatments (atomoxetine; the α2A agonists guanfacine and clonidine).
• Depression, anxiety, OCD: serotonergic treatments (SSRIs).
• Cataplexy in narcolepsy (REM atonia intruding into wakefulness); nightmare disorder.
• Diffuse midline glioma (H3 K27M, formerly DIPG): a pontine (also thalamic and spinal) tumor mostly affecting children aged 3–10; standard treatment is radiotherapy, and prognosis is poor. A
• Möbius syndrome (involvement of nerves VI and VII); co-occurrence with ASD has been reported.

Treatment

This region from the perspective of medication, psychotherapy and neuromodulation. Letter badges are evidence levels.

• Dordaviprone (ONC201; a D2/3 antagonist and mitochondrial ClpP activator): FDA accelerated approval (August 2025) from age 1 for H3 K27M-mutant diffuse midline glioma that has progressed despite prior treatment; response rate 22% in 50 patients, median duration of response 10.3 months. The first systemic drug approved for this tumor; a phase III trial at diagnosis is ongoing. A
• Noradrenergic and serotonergic treatments (atomoxetine, α2 agonists, SSRIs) are on the LC and raphe cards. A
• In Möbius syndrome: surgery for facial palsy (smile surgery) and speech and feeding therapy; the lack of facial expression in social communication can complicate ASD assessment. C

Assessment

Neuropsychological tasks and measures that probe this region's function.

• Polysomnography (REM sleep)
• Auditory brainstem responses (ABR)
• Pupillometry (an indirect index of LC activity — research); cranial nerve examination

Lesions and damage

Clinical findings expected with damage or dysfunction.

• Locked-in syndrome: ventral pons — consciousness and vertical eye movements are preserved.
• Internuclear ophthalmoplegia (MLF), Millard-Gubler syndrome.
• REM sleep behavior disorder.

In the model

How this structure is defined in the 3D model, and the data source.

Middle part of the CerebrA brainstem label (about z −21 to −47 mm; set by the anterior bulge).

References

Full citations for the card; links go to the paper (DOI) or a PubMed search.

1. Arrillaga-Romany I et al. ONC201 (dordaviprone) in recurrent H3 K27M-mutant diffuse midline glioma. J Clin Oncol 2024;42(13):1542–1552. DOI: 10.1200/JCO.23.01134
2. Aston-Jones G, Cohen JD. Adaptive gain and the role of the locus coeruleus–norepinephrine system in optimal performance. J Comp Neurol 2005;493(1):99–110. DOI: 10.1002/cne.20723
3. Raskind MA et al. Trial of prazosin for post-traumatic stress disorder in military veterans. N Engl J Med 2018;378(6):507–517. DOI: 10.1056/NEJMoa1507598
4. Roffwarg HP, Muzio JN, Dement WC. Ontogenetic development of the human sleep-dream cycle. Science 1966;152(3722):604–619. DOI: 10.1126/science.152.3722.604
5. Schenck CH et al. Chronic behavioral disorders of human REM sleep: a new category of parasomnia. Sleep 1986;9(2):293–308. DOI: 10.1093/sleep/9.2.293
6. Thannickal TC et al. Reduced number of hypocretin neurons in human narcolepsy. Neuron 2000;27(3):469–474. DOI: 10.1016/s0896-6273(00)00058-1