Unipolar brush cells in marmoset cerebellum and cochlear nuclei express calbindinSpatz, W B.1NeuroReport: January 17th, 2000 - Volume 11 - Issue 1 - p 1–4 Auditory and Vestibular Systems Abstract Author Information Unipolar brush cells (UBCs) are excitatory neurons in the mammalian cerebellum and cochlear nuclei (CN), including the CN of primates, as shown only recently. UBCs are readily identified by their expression of the calcium-binding protein calretinin (CR), except for those of the primate CN that hardly immunostain for CR. The present findings corroborate the existence of UBCs in the CN of a primate, Callithrix. Furthermore, evidence is presented for UBCs in the cerebellum and a small subpopulation of UBCs in the CN of Callithrix 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 indicate a certain interchangeability between these two calcium-binding proteins. 1Morphological Brain Research, Department of Oto-Rhino-Laryngology, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany Acknowledgements: Thanks to Mrs M. Seibert for technical assistance and Mr. W. Kuhn for animal care. The study was supported by the Deutsche Forschungsgemeinschaft (Sp70/5-3) and by the Forschungskommission of the Klinikum, University of Freiburg. Received 10 August 1999; accepted 15 October 1999 © 2000 Lippincott Williams & Wilkins, Inc.