Flexor reflex excitability in mice lacking galanin receptor galanin-R1.
This study was conducted to examine the excitability of the nociceptive flexor reflex and its sensitization by repetitive stimulation of C-fibers in anesthetized mice that lack the galanin-R1 receptor. Repetitive stimulation of C-fibers induced a gradual increase in reflex magnitude during the stimulation (wind-up), and a subsequent increase in spinal reflex excitability (central sensitization). This occurred in GAL-R1 -/-, GAL-R1 +/-, and +/+ wild-type controls, with no significant differences observed between genotypes. Intrathecal administration of galanin markedly blocked the sensitization following the repetitive stimulation in all three groups. No differences between wild-type or galanin-R1 receptor knockout mice were seen. These results confirm previous studies in rats, showing that intrathecal galanin reduces the central sensitization following wind-up. The present data indicate that this effect is probably mediated by receptors other than GAL-R1.
Grass
Stefan
S
Department of Laboratory Medicine, Division of Clinical Neurophysiology, Huddinge University Hospital, Karolinska Institutet, S-141 86 Stockholm, Sweden. strefan.grass@labmed.ki.se
Jacoby
Arie S
AS
Iismaa
Tiina P
TP
Crawley
Jacqueline N
JN
Xu
Xiao-Jun
XJ
Wiesenfeld-Hallin
Zsuzsanna
Z
D000704:Analysis of Variance; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004576:Electromyography / Q000379:methods; D019004:Galanin / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009132:Muscles / Q000187:drug effects / Q000502:physiology; D009412:Nerve Fibers / Q000502:physiology; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D044088:Receptors, Galanin; D018013:Receptors, Neuropeptide / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D012018:Reflex / Q000502:physiology*; D013497:Sural Nerve / Q000502:physiology
D044088:Receptors, Galanin; D018013:Receptors, Neuropeptide; D019004:Galanin