Axotomy induces intranuclear immunolocalization of neuron-specific enolase in facial and hypoglossal neurons of the rat.
Neuron-specific enolase as an enzyme of the glycolytic pathway is localized in the cytoplasm of nerve cells, but not in the cell nucleus. We have applied immunocytochemistry with 1:64,000 polyclonal anti-rat neuron-specific enolase to the brainstem of male and female adult Wistar rats following: (a) transection of the facial nerve with immediate microsurgical nerve suture (facial-facial anastomosis), (b) transection of the hypoglossal nerve with immediate suture (hypoglossal-hypoglossal anastomosis) and (c) transection of the facial and hypoglossal nerve with immediate suture of the proximal hypoglossal to the distal facial nerve stump (hypoglossal-facial anastomosis). Studying the intracellular immunolocalization of neuron-specific enolase in neurons of the facial and hypoglossal nucleus we detected that (1) in normal rats about 20% of all facial and hypoglossal neurons display not only cytoplasmic, but also intranuclear neuron-specific enolase-like immunoreactivity and (2) following any axotomy of the facial or hypoglossal peripheral nerve, the perikarya of all injured motoneurons react by an outstanding increase of neuron-specific enolase-like immunoreactivity in the karyoplasm. Similar findings were obtained in experiments on non-fixed cultured Neuro-2a cells that had been lesioned with hydrogen peroxide. Counting the absolute numbers of normal and reactive neurons at 1-365 days post axotomy revealed that the increase of neuron-specific enolase in neuronal cell nuclei is temporary and reversible. It is first detected at 2 days post axotomy, reaches its maximum at 10-18 days post axotomy and is no longer evident 56 days following surgery.(ABSTRACT TRUNCATED AT 250 WORDS)
Angelov
D N
DN
Institut I für Anatomie, Nasen- und Ohrenheilkunde der Universität zu Köln, Germany.
Neiss
W F
WF
Gunkel
A
A
Guntinas-Lichius
O
O
Stennert
E
E
D000714:Anastomosis, Surgical; D000818:Animals; D001369:Axons / Q000502:physiology; D002467:Cell Nucleus / Q000201:enzymology* / Q000648:ultrastructure; D005154:Facial Nerve / Q000201:enzymology / Q000502:physiology* / Q000601:surgery; D005260:Female; D007002:Hypoglossal Nerve / Q000201:enzymology / Q000502:physiology* / Q000601:surgery; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D009046:Motor Neurons / Q000166:cytology / Q000201:enzymology; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D010751:Phosphopyruvate Hydratase / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D012737:Sex Factors
D010751:Phosphopyruvate Hydratase