Tachykinins mediate changes in spinal reflexes after activation of unmyelinated muscle afferents in the rat. |
| |
Authors: | Z Wiesenfeld-Hallin X J Xu R H?kanson D M Feng K Folkers |
| |
Institution: | Department of Clinical Physiology, Karolinska Institute, Huddinge University Hospital, Sweden. |
| |
Abstract: | The effect of intrathecally applied tachykinin antagonist D-NicLys1, 3-Pal3, D-Cl2Phe5, Asn6, D-Trp7.9, Nle11-substance P, spantide II, on the long-term increase of spinal cord excitability after activation of unmyelinated muscle afferents was studied in decerebrate, spinalized, unanaesthetized rats. A conditioning stimulus train (1 Hz, 20 s) that activated unmyelinated fibres in the gastrocnemius muscle nerve facilitated the flexor reflex for about 1 h, which was strongly blocked by pretreatment with spantide II (3 micrograms). The present results indicate that the facilitation of the flexor reflex by conditioning stimulation of a muscle nerve is mediated by tachykinins and possibly other neuropeptides which may be released from the central terminals of these unmyelinated afferents. |
| |
Keywords: | |
|
|