Mosaic arrangement of SCP b -, FMRFamide-, and histamine-like immunoreactive sensory hair cells in the statocyst of the gastropod mollusc Pleurobranchaea japonica

Abstract

A pair of statocysts are located in the periganglionic connective tissue of the pedal ganglia of the opisthobranch mollusc Pleurobranchaea japonica. Lightand electron-microscopic observations show that the sensory epithelium of the statocyst consists of 13 diskshaped hair cells. Each hair cell sends a single axon to the cerebral ganglion through the static nerve. Neurotransmitters in the hair cells were examined by means of immunocytochemistry. Our results show that the 13 sensory hair cells include two SCPB-, three FMRFamide-, and eight histamine-like immunoreactive cells. One hair cell contains a transmitter substance other than SCPB-, FMRFamide, histamine, serotonin, or GABA. One of the two SCPB-like immunoreactive cells, located in the ventral region of the statocyst, is the largest cell in the statocyst. The other, located in the anterodorsal region, shows co-immunoreactivity to both SCPB and FMRFamide antisera. Among the three FMRFamide-like immunoreactive hair cells, one is located in the posteroventral region, separated from the other two, which are adjacent to each other in the anterodorsal region. All the eight histaminelike immunoreactive hair cells are adjacent to one another, occupying the remainder of a triangular pyramidshaped region. These immunoreactive cells are symmetrically placed in the right and left statocysts. This mosaic arrangement was identical among specimens. Thus the static nerve may code information about position or movement of the statoliths, with the use of different transmitters in the mosaic arrangement of the hair cells.

Distribution of histaminergic neurons and their modulatory effects on oscillatory activity in the olfactory center of the terrestrial slug Limax

“…5,6), both of which support the validity of the use of the current antiserum for the detection of HA via immunohistochemistry. Moreover, it is known that some of the hair cells in the statocyst are HAergic in the gastropods Aplysia and Pleurobranchaea (Soinila et al, 1990;Ohsuga et al, 2000), which is consistent with our present result (Figs. 1A, 5D, 5E).…”

Neurochemical characterization of nervous elements innervating the body wall of earthworms (Lumbricus, Eisenia): immunohistochemical and pharmacological studies

“…Bipolar HA-IR sensory cells have been demonstrated in the epithelial layer of the body wall of both Eisenia and Lumbricus. HA has also been identified in sensory neurons of various peripheral organs of other invertebrates species, such as the statocysts, lip and tentacle of gastropods (Soinila et al 1990;Ohsuga et al 2000;Hegedűs et al 2004) and in the photoreceptor cells of arthropods (Hardie 1987(Hardie , 1988(Hardie , 1989Nässel et al 1988;Pirvola et al 1988). The present study is, however, the first report of the possible simultaneous occurrence of HAcontaining sensory neurons with cell bodies located either at the periphery or in the CNS and suggests the involvement of HAergic efferentation in central networks in two ways: first, as an "internal" member of central network(s) and, second, as peripheral units transmitting sensory information to the members of central network(s).…”

Molecular analysis of two FMRFamide‐encoding transcripts expressed during the development of the tropical abalone haliotis asinina

“…One large family of peptides known as RFamides (Arg-Phe-NH 2 ) or FMRFamide (Phe-Met-Arg-Phe-NH 2 )-related peptides (FaRPs), are nearly ubiquitous within the Metazoa, in which they have been shown to have a diversity of roles as neurotransmitters, neuromodulators, and neurohormones Greenberg, 1977a, 1989;Bulloch et al, 1988;Lutz et al, 1992;Endo et al, 1995;Di Cosmo and Di Cristo, 1998;Di Cristo and Di Cosmo, 2007). FaRPs have been particularly well studied within gastropod molluscs, including Aplysia, Lymnaea and Helix (Lehman and Price, 1987;Benjamin and Burke, 1994;Suzuki et al, 1997;Oshuga et al, 2000), in which they have been demonstrated to have many functions including regulation of both cardiac and noncardiac muscles, nerves, and glands.…”