Is substance P a primary afferent neurotransmitter for nociceptive input? I. Analysis of pain-related behaviors resulting from intrathecal administration of substance P and 6 excitatory compounds
Intrathecal (i.t.) injection of substance P (SP), capsaicin, kainic acid, picrotoxin, strychnine, morphine, and L-glutamic acid in rats induced rhythmic scratching movements wit...