Cytotoxic targeting of isolectin IB4-binding sensory neurons
2001; Elsevier BV; Volume: 108; Issue: 1 Linguagem: Inglês
10.1016/s0306-4522(01)00377-3
ISSN1873-7544
AutoresLucy Vulchanova, Timothy H. Olson, Laura S. Stone, Maureen S. Riedl, R. Elde, Christopher N. Honda,
Tópico(s)Neuropeptides and Animal Physiology
ResumoThe isolectin I-B4 (IB4) binds specifically to a subset of small sensory neurons. We used a conjugate of IB4 and the toxin saporin to examine in vivo the contribution of IB4-binding sensory neurons to nociception. A single dose of the conjugate was injected unilaterally into the sciatic nerve of rats. The treatment resulted in a permanent selective loss of IB4-binding neurons as indicated by histological analysis of dorsal root ganglia, spinal cord, and skin from treated animals. Behavioral measurements showed that 7–10 days after the injection, conjugate-treated rats had elevated thermal and mechanical nociceptive thresholds. However, 21 days post-treatment the nociceptive thresholds returned to baseline levels. These results demonstrate the utility of the IB4-saporin conjugate as a tool for selective cytotoxic targeting and provide behavioral evidence for the role of IB4-binding neurons in nociception. The decreased sensitivity to noxious stimuli associated with the loss of IB4-binding neurons indicates that these sensory neurons are essential for the signaling of acute pain. Furthermore, the unexpected recovery of nociceptive thresholds suggests that the loss of IB4-binding neurons triggers changes in the processing of nociceptive information, which may represent a compensatory mechanism for the decreased sensitivity to acute pain.
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