| Median Eminence Neurons | |
|---|---|
| Lineage | Neuron > Hypothalamus > Neuroendocrine |
| Markers | GAD1, TPH1, CRH, AVP, OXT |
| Brain Regions | Median Eminence, Hypothalamus |
| Disease Vulnerability | Parkinson's Disease, Huntington's Disease, Neuroendocrine Disorders |
The median eminence is a key neuroendocrine structure located at the base of the hypothalamus, forming part of the ventral diencephalon. It serves as the primary interface between the central nervous system and the anterior pituitary gland, releasing hypothalamic releasing and inhibiting hormones into the hypophyseal portal system. Median eminence neurons are essential for neuroendocrine regulation and are affected in various neurodegenerative diseases, particularly those involving hypothalamic dysfunction.
The median eminence is a midline structure situated in the floor of the third ventricle, between the optic chiasm anteriorly and the mammillary bodies posteriorly. It contains a specialized capillary plexus (the primary plexus) connected to the anterior pituitary via the hypophyseal portal veins. This portal system allows neurosecretory neurons to deliver their products directly to the pituitary without entering the systemic circulation.
| Taxonomy | ID | Name / Label |
|---|
The median eminence occupies the ventral hypothalamus:
| Region | Description |
|---|---|
| External zone | Contains nerve terminals releasing hormones into portal capillaries |
| Internal zone | Contains axons of neurosecretory neurons |
| Tuberous zone | Contains tanycytes lining the third ventricle |
| Infundibular stem | Connects to posterior pituitary |
| Marker | Expression | Function |
|---|---|---|
| GAD1 | GABAergic neurons | Inhibitory neurotransmitter |
| TPH1 | Serotonergic neurons | Tryptophan hydroxylase |
| CRH | Parvocellular neurons | Corticotropin-releasing hormone |
| AVP | Magnocellular neurons | Arginine vasopressin |
| OXT | Magnocellular neurons | Oxytocin |
| GHRH | Arcuate nucleus | Growth hormone-releasing hormone |
| SST | Periventricular nucleus | Somatostatin |
The median eminence is the central hub for pituitary regulation:
Anterior Pituitary Control:
Neurosecretory neurons release hormones via two mechanisms:
The median eminence has a unique blood-brain barrier:
Median eminence involvement in PD includes:
Hypothalamic pathology in HD affects:
Hypothalamic dysfunction in AD:
Aging affects median eminence function:
Median eminence dysfunction causes:
](/cell-types/hypothalamus-neurons---parent-region
--arcuate-nucleus-neurons---appetite-regulation
--suprachiasmatic-nucleus-neurons---circadian-clock
--paraventricular-nucleus-neurons---stress-response
--parkinson's-disease---associated-disease
--hypothalamic-pituitary-adrenal-axis---stress-regulation)## Background
The study of Median Eminence Neurons has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.