Polyclonal antibodies against the rat NK1 receptor: characterization and localization in the spinal cord

We have developed antibodies against the NK1 receptor and have investigated its cellular distribution. Rabbit polyclonal antibodies were generated against peptide (19-32) of the rat brain NK1 receptor. They were very specific to the NK1 site as shown by ELISA against various epitopes of NK1, NK2 and NK3 receptors and by immunoblotting of proteins from bacteria transfected with rat brain NK1 receptor cDNA and from rat cortex. Determining how immunostained NK1 receptors are distributed in the rat spinal cord made it possible to identify the cellular structures on which NK1 receptors are located and where they form synapses with SP terminals. In the superficial layers of the dorsal horn, the NK1 receptors appeared mainly of dendritic nature and were, like SP, abundant. In the deep layers of the dorsal horn and in the ventral horn, they were associated mostly with cell bodies.