34th Annual Meeting, Society for Neuroscience, San Diego, CA. USA 22-26 Oct, 2004. Society for Neuroscience Abstracts
M. Millecamps, R. I. Jabakhanji, S. Lavarello, D. R. Chialvo, A.V. Apkarian
Department of Physiology, Northwestern University Medical School, Chicago, IL, 60611
Human brain imaging studies in our lab indicate that cortical and sub-cortical fear conditioning pathways may be fundamental to chronic neuropathic pain behavior.
In rat, D-cycloserine has been shown to selectively enhance extinction of fear conditioning.
We hypothesize that decreased fear conditioning would lead to analgesic behavior in chronic neuropathic rats.
We used spared nerve injury (SNI) neuropathic rats and followed their mechanical (Von Frey filaments test), cold (acetone test) allodynia, and paw position (score from 0 to 4 an index of the intensity of the protective behavior) responses following treatment with D-cycloserine.
D-cycloserine was applied either
Eight rats/dose and group
1 Acute oral D-cycloserine induces minimal analgesia
2 Acute intrathecal D-cycloserine has no effect
3 Repeated (chronic) oral D-cycloserine for 2 weeks results in robust analgesia
4 Repeated (chronic) oral D-cycloserine for 2 weeks induces longer-lasting analgesia