Morphological and Phenotypic Changes of Nociceptive Primary Afferent Neurons following Neurotmesis and Perineural Capsaicin Treatment
نویسندگان
چکیده
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 capsaicinpretreated 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. q 2003 Elsevier Ireland Ltd. All rights reserved.
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