Summary: EXPERIMENTAL NEUROLOGY 85,202-208 ( 1984)
Lumbar Dorsal Root Potentials Elicited by Stimulation
of Nucleus Locus Coeruleus
A. VANIA APKARIAN, CHARLES J. HODGE, JR., RICHARD T. STEVENS,
AND JOEL I. FRANCK'
Neurosurgery Laboratory, Upstate Medical Center, State University of New York,
Syracuse, New York 13210
Received June 20, 1983, revision received March 5, I984
Lumbar dorsal root potentials (DRP) were elicited by nucleus locus coeruleus (LC)
stimulation in the cat. Inhibition, by LC stimulation, of dorsal horn cells responding
to noxious inputs corresponded in time with the DRPs evoked by LC stimulation.
Comparing cutaneous stimulation-evoked DRPs with LC stimulation-evoked DRPs
and their respective effectson dorsal horn single-unit activity suggested a shared seg-
mental underlying mechanism and the possible involvement of the coeruleospinal
systemwith that of a diffuse noxious inhibitory suprasegmental loop.
The dorsolateral pons (DLP) of the cat, consisting of the nucleus locus
coeruleus (LC), nucleus subcoeruleus, the Kolliker-Fuse nucleus, and the
parabrachial nuclei, has a large concentration of noradrenaline (NA)-con-
taining cells (4, 14, 22) and has been shown to be the primary source of