Hypothalamus histaminergic fibers

Within the brain, histamine is produced both by mast cells and by certain neuronal fibers. Mast cells are a family of bone marrow-derived secretory cells that store and release high concentrations of histamine. They are prevalent in the thalamus, hypothalamus, dura mater, leptomeninges, and choroid plexus. Histaminergic neuronal cell bodies in the human are found in the tuberomamillary nucleus of the posterior basal hypothalamus. The fibers project into nearly all areas of the CNS, including the cerebral cortex, the brainstem, and spinal cord. 

Autoradiographic studies have revealed that H3 receptors are located in most areas of the brain with the highest content in the basal ganglia and the cortex [9]. H3 receptors are distributed with moderate density in the hypothalamus, where the highest density of histaminergic nerve fibers are found [4-5], and were demonstrated in the anterior, medial and posterior hypothalamus [8]. However, their localization in hypothalamic areas primarily involved in the regulation of pituitary hormone secretion were not studied in detail. In the pituitary gland the H3 receptors were scarce. 

Immunocytochemical studies have demonstrated the existence of histaminergic neurons, which are concentrated in the tuberomammillary nucleus of the posterior hypothalamus, and which give rise to fibers to almost all parts of the brain (reviewed by Wada... 

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