Neonatal sciatic nerve transection induces TUNEL labeling of neurons in the rat spinal cord and DRG.
Transection of a peripheral nerve in neonatal rats induces an extensive death of axotomized neurons. We demonstrate here that spinal motoneurons and sensory dorsal root ganglia neurons become TUNEL-labeled after sciatic nerve transection in neonatal rats, thus indicating that apoptotic mechanisms are involved in the death process. Interestingly, there is also a profound increase of TUNEL-labeled interneurons in the deep dorsal horn. This location suggests that an intact afferent input and/or contact with target cells is essential for interneuronal survival. Death of motoneurons and sensory neurons could be a result of the injury per se and/or the deprivation of neurotrophic substances, secondary to the loss of contact with target cells.
Oliveira
A L
AL
Department of Neuroscience, Karolinska Institute, Stockholm, Sweden.
Risling
M
M
Deckner
M
M
Lindholm
T
T
Langone
F
F
Cullheim
S
S
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000502:physiology; D016923:Cell Death / Q000502:physiology; D004253:DNA Nucleotidylexotransferase; D003856:Deoxyuracil Nucleotides; D005727:Ganglia, Spinal / Q000473:pathology*; D007395:Interneurons / Q000473:pathology; D009046:Motor Neurons / Q000473:pathology; D009474:Neurons / Q000473:pathology*; D009475:Neurons, Afferent / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000293:injuries*; D013116:Spinal Cord / Q000473:pathology*
D003856:Deoxyuracil Nucleotides; D004253:DNA Nucleotidylexotransferase