Early efferent innervation of the zebrafish lateral line

We examined the efferent innervation of the lateral line in zebrafish larva e. Three efferent nuclei were previously reported for the posterior line, t wo in the hindbrain and one in the ventral hypothalamus. Here we show that the same three nuclei innervate the anterior line as well. The rhombencepha lic neurons innervate either the anterior or the posterior line. The dience phalic neurons seem to innervate both lines as well as the ear. The diencep halic efferents are labeled by anti-tyrosine hydroxylase antibodies and pro bably use dopamine as a transmitter. They are among the very first catechol aminergic neurons to differentiate in the brain and extend branches into th e lateral line system almost as soon as the latter for ms. We discuss possi ble functions of the rhombencephalic and diencephalic efferents. (C) 2001 W ilry-Liss, Inc.