Unipolar brush cells in marmoset cerebellum and cochlear nuclei express calbindin

Unipolar brush cells (UBCs) are excitatory neurons in the mammalian cerebel lum and cochlear nuclei (CN), including the CN of primates, as shown only r ecently. UBCs are readily identified by their expression of the calcium-bin ding protein calretinin (CR), except for those of the primate CN that hardl y immunostain for CR. The present findings corroborate the existence of UBC s in the CN of a primate, Callithrix. Furthermore, evidence is presented fo r UBCs in the cerebellum and a small subpopulation of UBCs in the CN of Cal lithrix to express the calcium-binding protein calbindin (CB). This may be unique for Callithrix as CB-expressing UBCs have not been recognized in any other mammal. presence of CB but not CR in UBCs of the Callithrix CN may i ndicate a certain interchangeability between these two calcium-binding prot eins. Neuro-Report 11:1-4 (C) 2000 Lippincott Williams & Wilkins.