Spinal Botulinum Neurotoxin B: Effects on Afferent Transmitter Release and Nociceptive Processing

PLoS One. 2011 Apr 29;6(4):e19126. doi: 10.1371/journal.pone.0019126.


Botulinum neurotoxin B (BoNT-B) mediates proteolytic cleavage of VAMP I/II (synaptobrevins I/II), which prevents vesicle-membrane fusion and blocks neurotransmitter release. In the present study, we investigated the effects of BoNT-B on neurotransmitter release in vivo from spinal primary afferent sensory fibers and the effects of this blockade on nociception. With intrathecally (IT) delivered BoNT-B in C57B/l6 mice, we characterized the effects of such block on the release of substance P (SP) from spinal afferent nociceptors (as measured by neurokinin-1 receptor, NK1-R, internalization), spinal neuronal activation (as indicated by spinal C-Fos expression) and nociceptive behavior after intraplantar (IPLT) formalin. In addition, we investigated the effect of IT BoNT-B on spinal nerve ligation-induced tactile allodynia. A single percutaneous IT injection of BoNT-B 0.5 U at 2 or 5 days prior to IPLT formalin reduced NK1-R internalization and C-Fos expression. These effects correlated with BoNT-B cleavage of VAMPI/II protein in tissue lysate. IT BoNT-B also produced a corresponding reduction in phase 2 of formalin-evoked flinching behavior for over 30 days after IT injection. In mice with spinal nerve ligation (SNL), tactile allodynia was observed, which was attenuated by IT BoNT-B 0.5 U over the next 15 days, as compared to vehicle animals. These effects were observed without effects upon motor function. The specificity of the IT BoNT-B effect is indicated by: i) IT co-injection of BoNT-B and anti-BoNTB antibody prevented effects on SP release, and ii) IT BoNT-B 50 U in the Sprague Dawley rats showed no effect on formalin-evoked flinching or SNL-induced tactile allodynia, which is consistent with rat resistance to BoNT-B. IT BoNT-B blocks transmitter release from spinal primary afferents, and attenuates inflammatory nociceptive response and spinal nerve injury-induced neuropathic pain, in the absence of motor impairment. These observations provide an initial assessment of the ability of IT BoNT-B to regulate spinal nociceptive processing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Botulinum Toxins / metabolism*
  • Botulinum Toxins, Type A
  • Hyperalgesia / drug therapy
  • Hyperalgesia / pathology*
  • Immunohistochemistry / methods
  • Injections, Spinal
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Models, Biological
  • Neuralgia
  • Neurons / metabolism
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / metabolism*
  • Pain / physiopathology*
  • Rats
  • Rats, Sprague-Dawley
  • Spinal Cord / pathology
  • Spinal Nerves / drug effects
  • Spinal Nerves / pathology*


  • rimabotulinumtoxinB
  • Botulinum Toxins
  • Botulinum Toxins, Type A