TY - JOUR
T1 - Tracer-toxins
T2 - Cholera toxin B-saporin as a model
AU - Llewellyn-Smith, I. J.
AU - Martin, C. L.
AU - Arnolda, L. F.
AU - Minson, J. B.
PY - 2000/11/15
Y1 - 2000/11/15
N2 - We have shown previously that retrogradely-transported cholera toxin B (CTB)-saporin has eliminated sympathetic preganglionic neurons by 7 days after injection (Llewellyn-Smith, I.J., Martin, C.L., Arnolda, L.F., Minson, J.B., 1999. NeuroReport 10, 307). To ascertain whether this tracer-toxin can kill other types of neurons that transport CTB retrogradely with a similar time course, we injected CTB-saporin into the facial nerves of rats and allowed them to survive for 7 days. Facial motoneurons were counted ipsilateral and contralateral to the injected nerves in sections of perfused medulla processed to reveal immunoreactivity for choline acetyltransferase (ChAT). There was a statistically significant decrease in the number of ChAT-immunoreactive neurons ipsilateral to the injected nerve in three out of nine rats. Inadequate injections were probably the reason that most rats showed no decrease in motoneurons numbers after treatment with CTB-saporin, since the staining intensity and numbers of facial motoneurons that showed CTB-immunoreactivity varied markedly between rats after retrograde tracing with unconjugated CTB. These results show that CTB-saporin can eliminate motoneurons as well as sympathetic preganglionic neurons, indicate that protocols for the injection of tracer-toxins should be optimized to ensure maximum neuronal death and support our contention that CTB-saporin should kill any central neuron that expresses GM1 ganglioside, the membrane component to which CTB binds. (C) 2000 Elsevier Science B.V.
AB - We have shown previously that retrogradely-transported cholera toxin B (CTB)-saporin has eliminated sympathetic preganglionic neurons by 7 days after injection (Llewellyn-Smith, I.J., Martin, C.L., Arnolda, L.F., Minson, J.B., 1999. NeuroReport 10, 307). To ascertain whether this tracer-toxin can kill other types of neurons that transport CTB retrogradely with a similar time course, we injected CTB-saporin into the facial nerves of rats and allowed them to survive for 7 days. Facial motoneurons were counted ipsilateral and contralateral to the injected nerves in sections of perfused medulla processed to reveal immunoreactivity for choline acetyltransferase (ChAT). There was a statistically significant decrease in the number of ChAT-immunoreactive neurons ipsilateral to the injected nerve in three out of nine rats. Inadequate injections were probably the reason that most rats showed no decrease in motoneurons numbers after treatment with CTB-saporin, since the staining intensity and numbers of facial motoneurons that showed CTB-immunoreactivity varied markedly between rats after retrograde tracing with unconjugated CTB. These results show that CTB-saporin can eliminate motoneurons as well as sympathetic preganglionic neurons, indicate that protocols for the injection of tracer-toxins should be optimized to ensure maximum neuronal death and support our contention that CTB-saporin should kill any central neuron that expresses GM1 ganglioside, the membrane component to which CTB binds. (C) 2000 Elsevier Science B.V.
KW - Cholera toxin B subunit
KW - Facial nucleus
KW - Medulla
KW - Motoneurons
KW - Neurotoxin
KW - Ribosomal inactivating proteins
UR - http://www.scopus.com/inward/record.url?scp=0034669819&partnerID=8YFLogxK
U2 - 10.1016/S0165-0270(00)00298-3
DO - 10.1016/S0165-0270(00)00298-3
M3 - Article
C2 - 11074098
AN - SCOPUS:0034669819
VL - 103
SP - 83
EP - 90
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
SN - 0165-0270
IS - 1
ER -