*Review* **Ion Channels Involved in Substance P-Mediated Nociception and Antinociception**

**Chu-Ting Chang 1, Bo-Yang Jiang <sup>1</sup> and Chih-Cheng Chen 1,2,\***


Received: 5 March 2019; Accepted: 27 March 2019; Published: 30 March 2019

**Abstract:** Substance P (SP), an 11-amino-acid neuropeptide, has long been considered an effector of pain. However, accumulating studies have proposed a paradoxical role of SP in anti-nociception. Here, we review studies of SP-mediated nociception and anti-nociception in terms of peptide features, SP-modulated ion channels, and differential effector systems underlying neurokinin 1 receptors (NK1Rs) in differential cell types to elucidate the effect of SP and further our understanding of SP in anti-nociception. Most importantly, understanding the anti-nociceptive SP-NK1R pathway would provide new insights for analgesic drug development.

**Keywords:** substance P; NK1R; nociception; anti-nociception; pain
