Confocal imaging of HuC/D RNA-binding proteins in adult rat primary sensory neurons

HuC/D RNA-binding proteins are antigens that are specifically expressed in nerve cells. In the present study, immunocytochemistry and laser confocal m icroscopy were used to study the cellular distribution of HuC/D RNA-binding proteins in adult rat primary sensory neurons. Colocalization with the pro tein gene product 9.5 (PGP 9.5) was used to identify sensory neurons. Confo cal laser imaging showed that HuC/D antigens are expressed in the cytoplasm of all rat primary sensory neurons. Most neurons also showed anti-HuC/D im muno-positivity in the nucleus. The demonstration of the ubiquitous express ion of HuC/D antigens in primary sensory neurons gives us a possible explan ation for the severe pathological lesions observed in dorsal root ganglia i n association with the paraneoplastic Hu syndrome.