Boston University Department of Biology

Faculty Profiles

Current Research

Vocal signals produced by animals in the context of reproduction are often sexually distinct. Research in my laboratory is focused on understanding neural mechanisms underlying sexually distinct vocal communication using the African clawed frog (Xenopus laevis) as a model. Male and female Xenopus vocalize underwater, and generate sound using a single pair of laryngeal muscles. The sex differences in the vocalizations can be reduced to differences in muscle contraction rates, and, in turn, differences in the firing rates of laryngeal motoneurons (male motoneurons fire at faster rates than female motoneurons). The simplicity of this behavior and its effector pathway make Xenopus vocal system an ideal model for understanding the neural basis of behavior. In addition, sexual differentiation remains plastic well into adulthood in Xenopus; androgen treatment masculinizes vocalizations of adult females within 1 to 3 months. Such a rapid transformation of behavior provides us with an opportunity to study how the central vocal pathways are modified in response to androgen at cellular and circuit levels. An additional advantage that Xenopus vocal systems offer is that vocal production can be studied in vitro. Recently, we have developed a “singing brain in a dish” preparation from which “fictive song” (neuronal activity that generates vocalizations in vivo) can be repeatedly evoked. Using this preparation, we are currently investigating how neurons in the central vocal pathways fire together to generate sex-specific vocal patterns, how vocalizations are initiated, and how they are modified in response to androgen.

Courses Taught

• BI 466/666 Neuroethology

Selected Publications

• Zornik EJ, Yamaguchi A (2008). Sexually differentiated central pattern generators in Xenopus laevis. Trends in Neurosci, 296-302.
• Rhodes HJ, Yu HJ, Yamaguchi A (2007). Xenopus vocalizations are controlled by a sexually differentiated hindbrain central pattern generator. J Neurosci. 27, 1485-97.
• Potter KA, Bose TO, Yamaguchi A (2005). Androgen induced vocal transformation in adult African clawed frogs. J Neurophysiol. 94, 415-28.
• Yamaguchi A, Kaczmarek LK, Kelley DB (2003). Functional specialization of male and female vocal motoneurons. J Neurosci 23, 11568-11576.
• Yamaguchi A. (2001). Sex differences in vocal learning. Nature, 411, 257-258.
• Yamaguchi A, Kelley DB (2000). Generating sexually differentiated vocal patterns: laryngeal nerve and EMG recordings from vocalizing male and female African clawed frogs (Xenopus laevis). J Neurosci, 20, 1559-1567.
• Yamaguchi A. (1998). Can a sexually dimorphic learned birdsong be used for male-female recognition? Behaviour 135, 833-844.
• Okanoya K, Yamaguchi A (1997). Adult bengalese finches (Lonchura striata var. domestica) require real-time auditory feedback to produce normal song syntax. J. Neurobiol, 33, 343-356.