Selective C-fiber deafferentation of the spinal dorsal horn prevents lesion-induced transganglionic transport of choleragenoid to the substantia gelatinosa in the rat.
The effect of neonatal capsaicin treatment, producing selective elimination of almost all unmyelinated C-fiber sensory axons, was studied on lesion-induced transganglionic labelling of the substantia gelatinosa of the spinal cord by choleragenoid. In both control and capsaicin-pretreated rats, the injection of choleragenoid-horseradish peroxidase conjugate into the intact sciatic nerves resulted in intense labelling only of the deeper layers of the spinal dorsal horn. In the control but not the capsaicin-pretreated rats, the injection of the tracer into sciatic nerves transected 2 weeks previously produced an intense homogeneous labelling of the substantia gelatinosa. It is concluded that the uptake and axonal transport of choleragenoid by capsaicin-sensitive C-fiber afferents may be accounted for by the lesion-induced transganglionic labelling of the substantia gelatinosa, rather than by A-fiber sprouting.
Jancsó
Gábor
G
Department of Physiology, University of Szeged, Dóm tér 10, H-6720 Szeged, Hungary. jancso@phys.szote.u-szeged.hu
Sántha
Péter
P
Szigeti
Csaba
C
Dux
Mária
M
D000344:Afferent Pathways / Q000293:injuries* / Q000503:physiopathology; D000818:Animals; D001370:Axonal Transport / Q000187:drug effects / Q000502:physiology*; D002211:Capsaicin / Q000494:pharmacology; D048429:Cell Size / Q000502:physiology; D002772:Cholera Toxin / Q000493:pharmacokinetics*; D003714:Denervation; D004195:Disease Models, Animal; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020439:Growth Cones / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D006735:Horseradish Peroxidase / Q000493:pharmacokinetics; D008297:Male; D009410:Nerve Degeneration / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology; D009413:Nerve Fibers, Myelinated / Q000187:drug effects / Q000378:metabolism; D036421:Nerve Fibers, Unmyelinated / Q000187:drug effects / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000502:physiology; D059348:Peripheral Nerve Injuries; D010525:Peripheral Nerves / Q000503:physiopathology; D017729:Presynaptic Terminals / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D013376:Substantia Gelatinosa / Q000166:cytology / Q000378:metabolism*
D002772:Cholera Toxin; D006735:Horseradish Peroxidase; D002211:Capsaicin