Alz-50 recognizes epitopes in primary sensory fibres and in neurons of the substantia gelatinosa of the spinal cord. An ultrastructural study in the rat.
The monoclonal antibody Alz-50 has been proposed as a marker for cellular pathological changes in Alzheimer's disease. However, it has been reported that this antibody also reacts with specific epitopes in normal individuals. Furthermore, intense Alz-50 immunoreactivity has been recently described in the hypothalamus and spinal cord of rat and monkey. In the present study, we analysed the distribution pattern of Alz-50 immunostaining in the spinal cord of the adult rat. Using light microscopy, immunostained fibres and varicosities were detected mainly in laminae I-II, although some immunostaining lamina I and the outer two thirds of lamina II. The varicosities appeared either scalloped or dome-shaped and contained numerous agranular synaptic vesicles and a few dense-core vesicles. Most varicosities were presynaptic to dendrites. A few immunostained cell bodies and dendrites were also observed, but glial cells were never immunostained. Some ultrathin sections were processed for postembedding immunogold detection of calcitonin gene-related peptide and GABA immunoreactivities. Most of the varicosities which were immunoreactive for Alz-50 also showed calcitonin gene-related peptide immunoreactivity. In contrast, GABA immunoreactivity was never co-localized with Alz-50 immunoreactivity. These results indicate that, in the superficial dorsal horn, the epitope recognized by the Alz-50 antibody is located mainly, but not exclusively, in primary sensory fibres.
Liberini
P
P
Department of Pharmacology and Therapeutics, McGill University, Montréal, Canada.
Piccardo
P
P
Ma
W
W
Mattiuzzo
V
V
Cuello
A C
AC
Ribeiro-Da-Silva
A
A
D000818:Animals; D000911:Antibodies, Monoclonal; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D002462:Cell Membrane / Q000648:ultrastructure; D003712:Dendrites / Q000737:chemistry / Q000648:ultrastructure; D000939:Epitopes / Q000032:analysis*; D007150:Immunohistochemistry; D007382:Intermediate Filaments / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008870:Microtubules / Q000648:ultrastructure; D008928:Mitochondria / Q000648:ultrastructure; D009412:Nerve Fibers / Q000737:chemistry / Q000648:ultrastructure*; D009474:Neurons / Q000737:chemistry / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar; D013376:Substantia Gelatinosa / Q000648:ultrastructure*; D005680:gamma-Aminobutyric Acid / Q000032:analysis
D000911:Antibodies, Monoclonal; D000939:Epitopes; D005680:gamma-Aminobutyric Acid; D015740:Calcitonin Gene-Related Peptide