Recurrent facial taste neurons of sea catfish Plotosusjaponicus: morphology and organization in the ganglion

Abstract

This study investigated the morphology of the recurrent facial taste neurons and their organization in the recurrent ganglion of the sea catfish Plotosus japonicus. The recurrent ganglion is independent of the anterior ganglion, which consists of trigeminal, facial and anterior lateral line neurons that send peripheral fibres to the head region. The recurrent taste neurons are round or oval and bipolar, with thick peripheral and thin central fibres, and completely wrapped by membranous layers of satellite cells. Two peripheral nerve branches coursing to the trunk or pectoral fin originate from the recurrent ganglion. The results presented here show that the trunk and pectoral-fin neurons are independently distributed to form various sizes of groups, and the groups are intermingled throughout the ganglion. No distinct topographical relationship of the two nerve branches occurs in the ganglion. Centrally, the trunk and pectoral-fin branches project somatotopically in the anterolateral and intermediate medial regions of the trunk tail lobule of the facial lobe, respectively.

Distribution, Innervation, and Cellular Organization of Taste Buds in the Sea Catfish, <b><i>Plotosus japonicus</i></b>

“…The Japanese sea catfish, P. japonicus , has been utilized in numerous studies on gustatory capabilities in teleost fish [Kiyohara et al, 1986Marui et al, 1988;Sakata et al, 2001;Denil et al, 2013;Caprio et al, 2014Caprio et al, , 2015. Here, we used whole-mount immunohistochemistry to characterize the morphology and innervation of the external and intraoral taste buds of this interesting species.…”

“…The gustatory system of the Japanese sea catfish, Plotosus japonicus , has been examined in many studies [Kiyohara et al, 1986Marui et al, 1988;Sakata et al, 2001;Denil et al, 2013]. A recent study showed that P. japonicus could sense decreases of ≤ 0.1 pH unit in environmental seawater, associated with the increase of H + / CO 2 from the respiration of prey, and utilized this ability to detect the prey [Caprio et al, 2014].…”