Activation of substance P receptors leads to membrane potential responses in cultured astrocytes

✍ Scribed by Marion Wienrich; H. Kettenmann

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 515 KB
• Volume: 2
• Category: Article
• ISSN: 0894-1491
• DOI: 10.1002/glia.440020304

✦ Synopsis

Cultured astrocytes from rat cortex and spinal cord responded with different types of membrane potential changes upon brief (10 seconds) applications of the natural neurokinin agonists substance P and neurokinin A. The most prominent type of response was a long-lasting membrane depolarization. In some cells, an initial rapid depolarization followed by a partial repolarization preceded the slow depolarizing event. Few astrocytes responded with a hyperpolarization of the membrane. Selective agonists at the NK-1 receptive site, substance P-methyl ester (SP-OME) and septide, mimicked the response to the natural neurokinins as did DiMe-C7, a selective NK-3 receptor agonist. A putative neurokinin antagonist, (D-A~~',D-P~O~,D-T~~~,~,L~U~~)SP (DADPDT) partially blocked membrane potential responses induced by substance P, SP-OME, septide, DiMe-C7, and NKA. The authors conclude that astrocytes express NK-1 and NK-3 receptors, which upon activation affect the electrical properties of these cells.