DISTRIBUTION OF MYOMODULIN-LIKE AND BUCCALIN-LIKE IMMUNOREACTIVITIES IN THE CENTRAL-NERVOUS-SYSTEM AND PERIPHERAL-TISSUES OF THE MOLLUSK, CLIONE-LIMACINA

The distribution of the myomodulin-like and buccalin-like immunoreacti vities in the central nervous system and peripheral tissues associated with feeding was examined in the pteropod mollusc Clione limacina by using wholemount immunohistochemical techniques. Immunoreactive neuron s and cell clusters were located in all central ganglia except the ple ural ganglia, with approximately 50 central neurons reactive to myomod ulin antiserum and 60 central neurons reactive to buccalin antiserum. All central ganglia contained a dense network of myomodulin- and bucca lin-immunoreactive processes in their neuropil regions and connectives . In the periphery, the primary attention was focused on the tissues a ssociated with feeding, especially feeding structures unique to Clione , such as hook sacs and buccal cones, which are used for prey capture and acquisition. All of these feeding structures contained myomodulin- immunoreactive and buccalin-immunoreactive fibers, with each peptide f amily showing specific innervation fields that were common in buccal c ones and were totally different in the hook sacs. The specific central and peripheral distribution of myomodulin-like and buccalin-like immu noreactivities as well as specific effects of the exogenous peptides o n identified neurons involved in the control of feeding behavior and s wimming suggest that neuropeptides from myomodulin and buccalin famili es act as neurotransmitters or neuromodulators in a variety of central circuits and in the peripheral neuromuscular systems associated with feeding in Clione limacina. (C) 1997 Wiley-Liss, Inc.