Neurokinin A Excites Nociceptive and Non-Nociceptive Dorsal Horn Neurones in the Cat Spinal Cord

Neurokinin A is a recently discovered mammalian neurokinin [1,2]. Immuno reactivity for neurokinin A is found in the cell bodies of primary afferent neurones [3] and this peptide appears to co-exist with substance P [3,4]. Previous studies have reported that substance P has a preferential excitatory effect on nociceptive neurones in the spinal dorsal horn [5,6]. Therefore, to test the possible functional specificity of neurokinin A, the present study was done in which this peptide was iontophoretically applied to functionally identified dorsal horn neurones.