Tachykinin NK1 and NK3 receptors in the prefrontal cortex of the human brain

1. The tachykinins are neuropeptides found in both the central and peripher al nervous systems that play a role in inflammation and pain mechanisms and some autonomic reflexes and behaviours. 2. Although the distribution of the tachykinin receptors has been described in the brains of various animal species, little is known about the distrib ution of the NK1 and NK3 receptors in the human brain. 3. The present paper examines the distribution of the NK1 and NK3 receptors in the prefrontal cortex of formalin-fixed post-mortem human brain tissue by immunohistochemical techniques. 4. The majority of NK1 receptor immunoreactivity appeared as a thin band of punctate staining at the pial surface, with dark brown dots of NK1 recepto r immunoreactivity predominantly scattered across the mid to upper cortical layers. 5. The NK3 receptor immunoreactivity was found in the glia limitans at the pial surface, where astrocytes and beaded fibres were intensely stained. Do ts of NK3 receptor immunoreactivity were scattered across all cortical laye rs. In the white matter, astrocytes and beaded fibres displayed NK3 recepto r immunoreactivity, particularly in areas surrounding blood vessels.