1. Department of Neuroscience and Behavior; University of São Paulo, School of Medicine at Ribeirão Preto; Ribeirão Preto SP 14049-900 Brazil
2. National Institute on Deafness and Other Communication Disorders, National Institutes of Health; Bethesda MD 20892 USA
3. Department of Cell and Molecular Biology; University of São Paulo, School of Medicine at Ribeirão Preto; Ribeirão Preto SP 14049-900 Brazil
4. Department of Basic Sciences/Physiology; Federal University of Health Sciences at Porto Alegre; Porto Alegre RS 90050-110 Brazil