Anatom3DLocus coeruleus
Locus caeruleus · Modrá skvrna
Nervous system
Looks like
A small blue-tinged cluster of cells in the upper pons, on the floor of the fourth ventricle — the name means 'blue spot'.
What it does
The brain's main source of noradrenaline: sets alertness and attention, sharpens focus under stress and switches off during REM sleep.
Keeping it well
It is among the first places damaged in Alzheimer's and Parkinson's disease. Overactivity drives panic, and the shakes and sweats of opioid withdrawal; clonidine calms it.
Related conditions
- Acute liver failure
- ADHD
- African trypanosomiasis (sleeping sickness)
- Alcohol withdrawal and delirium tremens
- Altitude sickness
- Alzheimer's disease
- Amyloidosis (AL and ATTR)
- Autism spectrum disorder
- Bipolar disorder
- Birth asphyxia (hypoxic-ischaemic encephalopathy)
- Body dysmorphic disorder
- Botulism
- Brain abscess
- Brain aneurysm
- Brain tumour (glioma & meningioma)
- Cerebral palsy
- Chiari malformation and syringomyelia
- Chickenpox (varicella)
- Chronic insomnia
- Chronic neuropathic pain
- Chronic pain syndrome
- Cluster headache
- Concussion (mild TBI)
- Congenital hypothyroidism
- Cryptococcal meningitis
- Delirium
- Dementia with Lewy bodies
- Down syndrome (trisomy 21)
- Drowning
- Eating disorders
- Encephalitis
- Epilepsy
- Essential tremor & dystonia
- Fainting (syncope)
- Febrile seizures
- Fibromyalgia
- Fragile X syndrome
- Frailty & falls in older age
- Functional (somatic) symptom disorder
- Generalised anxiety disorder
- Guillain-Barré syndrome
- Haemorrhagic stroke
- Heat exhaustion & heatstroke
- Hepatic encephalopathy
- Huntington's disease
- Hydrocephalus
- Hypoglycaemia (low blood sugar)
- Intellectual disability
- Ischaemic stroke
- Japanese encephalitis
- Lead poisoning
- Long COVID (post-viral syndrome)
- Lyme disease
- Major depressive disorder
- ME/chronic fatigue syndrome
- Measles
- Medication-overuse headache
- Meningitis
- Migraine
- Multiple sclerosis
- Myasthenia gravis
- Narcolepsy
- Neurocysticercosis
- Normal pressure hydrocephalus
- Panic disorder
- Parkinson's disease
- Peripheral neuropathy
- Phenylketonuria (PKU)
- Poisoning & overdose
- Post-traumatic stress disorder
- Postnatal depression
- Postpartum psychosis
- Rabies
- Restless legs syndrome
- Roseola (sixth disease)
- Schizophrenia
- Self-harm and suicidal crisis
- Shingles (herpes zoster)
- Subdural haematoma
- Substance use disorder
- Sudden infant death syndrome
- Tension-type headache
- Tetanus
- Thrombotic thrombocytopenic purpura (TTP)
- Tick-borne encephalitis
- Tics and Tourette syndrome
- Toxoplasmosis & CMV
- Transient ischaemic attack
- Traumatic brain injury (moderate to severe)
- Trigeminal neuralgia
- Tuberous sclerosis complex
- Vascular dementia
- Vestibular schwannoma (acoustic neuroma)
- Vitamin B1, C and other deficiencies