Intrathecal application of cyproheptadine impairs locomotion in intact rats.
In intact adult rats, cyproheptadine, a 5-HT2 antagonist, administered intrathecally at the midlumbar segments was found to impair hindlimb locomotor movements during overground locomotion. These effects were dose-dependent; they varied from transient complete hindlimb paraplegia seen at doses of 300 microg/20 microl, to short-lasting trunk instability at doses of 100 microg/20 microl. After the return of overground locomotion, transient abduction of one of the hindlimbs was observed in some animals. These findings demonstrate that the blockade of 5-HT2 receptors affects locomotion in intact rats. Our results provide support for the hypothesis of serotonergic involvement in rat locomotion, which, so far, has been based mainly on the effects of 5-HT2 agonists on the recovery of locomotion in spinal rats.
Majczyński
Henryk
H
Department of Neurophysiology, The Nencki Institute of Experimental Biology, Pasteur Street 3, 02-093 Warsaw, Poland.
Cabaj
Anna
A
Górska
Teresa
T
D000818:Animals; D003533:Cyproheptadine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006614:Hindlimb / Q000187:drug effects / Q000502:physiology*; D007278:Injections, Spinal; D008124:Locomotion / Q000187:drug effects* / Q000502:physiology*; D008159:Lumbar Vertebrae / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D058830:Serotonin 5-HT2 Receptor Antagonists; D012702:Serotonin Antagonists / Q000008:administration & dosage; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism*
D058830:Serotonin 5-HT2 Receptor Antagonists; D012702:Serotonin Antagonists; D003533:Cyproheptadine