Morphological and functional properties distinguish the substance P and gastrin-releasing peptide subsets of excitatory interneuron in the spinal cord dorsal horn by Dickie, AC, Bell, AM, Iwagaki, N, Polgár, E, Gutierrez-Mecinas, M, Kelly, R, Lyon, H, Turnbull, K, West, SJ, Etlin, A, Braz, J, Watanabe, M, Bennett, DLH, Basbaum, AI, Riddell, JS, Todd, AJ