Hypoalgesia in mice with a targeted deletion of the tachykinin 1 gene

• DOI: 10.1073/pnas.95.5.2630
• Publication Date: 2002-07-26T14:40:11Z
• Authors: Andreas Zimmer; Anne M. Zimmer; Judith Baffi; Ted Usdin; Kay Reynolds; Monika König; Miklós Palkovits; Éva Mezey
• Keywords: Mice, Knockout; Neurons; 0303 health sciences; Calcitonin Gene-Related Peptide; Neurokinin A; Pain; Substance P; Mice, Inbred C57BL; Mice; 03 medical and health sciences; Spinal Cord; Formaldehyde; Ganglia, Spinal; Animals; Alleles; Biomarkers; Gene Deletion; In Situ Hybridization; Acetic Acid

The tachykinin neuropeptides, substance P and substance K, are produced in nociceptive primary sensory neurons and in many brain regions involved in pain signaling. However, the precise role and importance of these neuropeptides in pain responses has been debated. We now show that mice that cannot produce these peptides display no significant pain responses following formalin injection and have an increased pain threshold in the hotplate test. On the other hand, the mutant mice react normally in the tail flick assay and acetic acid-induced writhing tests. These results demonstrate that substance P and/or substance K have essential functions in specific responses to pain.