Fig. 1. (A) Sagittal schematic showing the functional neuroanatomy of the mormyrid electromotor system, based on Bell et al. (1983), Carlson (2002b, 2003) and von der Emde et al. (2000). Excitatory terminals are identified by flat lines, inhibitory terminals by solid circles. Red denotes medullary electromotor nuclei, blue denotes mesencephalic and diencephalic electromotor nuclei (topic of the current study), and green denotes corollary discharge nuclei. BCA, bulbar command-associated nucleus; C3, third cerebellar lobule; CN, command nucleus; DP, dorsal posterior nucleus of the thalamus; EGp, eminentia granularis pars posterior; EL, exterolateral nucleus of the torus semicircularis; ELL, electrosensory lateral line lobe; EMN, electromotor neurons; IL, inferior lobe of the hypothalamus; MCA, mesencephalic command-associated nucleus; MRN, medullary relay nucleus; OB, olfactory bulb; PCN, precommand nucleus; Tel, telencephalon; TM, tectum mesencephali; Val, valvula of the cerebellum; VPd, dorsal subdivision of the ventroposterior nucleus of the torus semicircularis. (B) Examples of the three burst display types produced by freely behaving Brienomyrus brachyistius. Quantitative analysis indicates that they fall into distinct categories based on unique temporal patterns of EOD production (Carlson and Hopkins, unpublished observations).