Selective C-fiber deafferentation of the spinal dorsal horn prevents lesion-induced transganglionic transport of choleragenoid to the substantia gelatinosa in the rat

• Published in: Neuroscience letters Vol. 361; no. 1; pp. 204 - 207
• Main Authors: Jancsó, Gábor, Sántha, Péter, Szigeti, Csaba, Dux, Mária
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 06.05.2004
• Subjects: Afferent Pathways - injuries; Afferent Pathways - physiopathology; Animals; Axonal Transport - drug effects; Axonal Transport - physiology; Capsaicin; Capsaicin - pharmacology; Cell Size - physiology; Cholera Toxin - pharmacokinetics; Choleratoxin B subunit; Denervation; Disease Models, Animal; Ganglia, Spinal - cytology; Ganglia, Spinal - drug effects; Ganglia, Spinal - metabolism; Growth Cones - drug effects; Growth Cones - metabolism; Growth Cones - ultrastructure; Horseradish Peroxidase - pharmacokinetics; Male; Nerve Degeneration - chemically induced; Nerve Degeneration - pathology; Nerve Degeneration - physiopathology; Nerve Fibers, Myelinated - drug effects; Nerve Fibers, Myelinated - metabolism; Nerve Fibers, Unmyelinated - drug effects; Nerve Fibers, Unmyelinated - metabolism; Nerve transection; Neuronal Plasticity - physiology; Pain; Peripheral Nerve Injuries; Peripheral Nerves - physiopathology; Plasticity; Presynaptic Terminals - drug effects; Presynaptic Terminals - metabolism; Presynaptic Terminals - ultrastructure; Rats; Rats, Wistar; Sensory ganglion; Sprouting; Substantia Gelatinosa - cytology; Substantia Gelatinosa - metabolism; Sprouting; Pain; Choleratoxin B subunit; Capsaicin; Plasticity; Nerve transection; Sensory ganglion
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2003.12.063

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.