Modulation of neuropathic pain by galanin and neuropeptide Y at the level of the medulla in rats.
This study was conducted to examine the role of galanin and neuropeptide Y (NPY) in the modulation of neuropathic pain at the level of the medulla. Under pentobarbital anesthesia, Sprague-Dawley rats were subjected to neuropathic surgery. Intracisternal injections of galanin and NPY were performed 2 weeks after nerve injury and mechanical allodynia was monitored. In an electrophysiological experiment, rats were reanesthetized with urethane and the responses of gracile nucleus neurons to mechanical stimulation were observed. Galanin and NPY were applied microiontophoretically. Intracisternally administered NPY reduced neuropathic pain behaviors in a dose-dependent manner. High doses of galanin inhibited neuropathic pain behaviors. Iontophoretically ejected galanin and NPY inhibited responses of gracile nucleus neurons to mechanical stimulation. These results suggest that galanin and NPY play a role in modulating neuropathic pain in the gracile nucleus of the medulla.
Jung
Se Jung
SJ
Department of Physiology, Brain Research Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
Chang
Jin Woo
JW
Won
Ran
R
Cha
Myeoung Hoon
MH
Nam
Taick Sang
TS
Lee
Hye-Jung
HJ
Lee
Bae Hwan
BH
D000200:Action Potentials / Q000187:drug effects; D000704:Analysis of Variance; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004609:Eliminative Behavior, Animal; D019004:Galanin / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D006930:Hyperalgesia / Q000188:drug therapy / Q000209:etiology; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009046:Motor Neurons / Q000187:drug effects; D009437:Neuralgia / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D009478:Neuropeptide Y / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000187:drug effects; D010812:Physical Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects
D009478:Neuropeptide Y; D019004:Galanin