Differential subcellular immunolocalization of voltage-gated calcium channel alpha 1 subunits in the chinchilla cristae ampullaris

The immunohistochemical localization of alpha 1A, alpha 1B, alpha 1C, alpha 1D and alpha 1E voltage-gated calcium channel subunits was investigated in the chinchilla cristae ampullaris and Scarpa's ganglia at the Light and el ectron microscopy level with the use of specific antipeptide antibodies dir ected against these subunits. The stereocilia membrane of type I and type L I hair cells was immunoreactive for alpha 1B along its entire length. The b asolateral membrane of both types of hair cells was alpha 1B, alpha 1C and alpha 1D immunoreactive. Neurons in the Scarpa's ganglia and afferent nerve terminals in the cristae were immunoreactive for alpha 1C and alpha 1B. No specific immunoreactivity to alpha 1A or alpha 1E was seen in the sensory epithelia or ganglia. These findings are consistent with the presence of alpha 1B (N-type channel ), alpha 1C and alpha 1D (L-type channels) in the vestibular hair cells, an d alpha 1B (N-type channel) and alpha 1C (L-type channel) in primary vestib ular neurons. (C) 1999 IBRO. Published by Elsevier Science Ltd.