Differential subcellular immunolocalization of voltage-gated calcium channel α1 subunits in the chinchilla cristae ampullaris

The immunohistochemical localization of α1A, α1B, α1C, α1D and α1E voltage-gated calcium channel subunits was investigated in the chinchilla cristae ampullaris and Scarpa's ganglia at the light and electron microscopy level with the use of specific antipeptide antibodies directed against these subunits. The stereocilia membrane of type I and type II hair cells was immunoreactive for α1B along its entire length. The basolateral membrane of both types of hair cells was α1B, α1C and α1D immunoreactive. Neurons in the Scarpa's ganglia and afferent nerve terminals in the cristae were immunoreactive for α1C and α1B. No specific immunoreactivity to α1A or α1E was seen in the sensory epithelia or ganglia. These findings are consistent with the presence of α1B (N-type channel), α1C and α1D (L-type channels) in the vestibular hair cells, and α1B (N-type channel) and α1C (L-type channel) in primary vestibular neurons.