FMRFamide-like immunoreactivity in the isolated,in vivo cultured ventral ganglion of the fly,Sarcophaga bullata (Parker) (Diptera: Sarcophagidae)

The influence of peripheral connectivity on the survival and differentiation of Phe-Met-Arg-Phe-amide-like immunoreactive (FLI) neurons in the ventral ganglion (VG) of the fly Sarcophaga bullata (Diptera: Sarcophagidae) was examined. Isolated larval VG were cultured in vivo for 13 days. The ganglia had undergone metamorphosis and resembled in situ metamorphosed VG in morphology and in the number and location of FLI neurons. The 3 pairs of large thoracic FLI neurons survived and became translocated to the midventral position extending immunoreactive axons into the dorsal neuropil. The 5 pairs of small FLI neurons also appeared de novo in the abdominal ganglion. However, the dorsal neural sheath of the cultured VG was devoid of FMRFamide-like immunoreactivity that was so characteristic of adult VG, which suggests the importance of peripheral connectivity for the metamorphic modification of FLI neurons.     

FMRFamide-like immunoreactivity in the ventral ganglion of the fly Sarcophaga bullata: metamorphic changes.

1. Localization of FMRFamide-like immunoreactivity was examined in the ventral ganglion of the fly Sarcophaga bullata using the indirect immunofluorescent method. 2. There are six large cells in the thoracic ganglion which are highly immunoreactive at all stages of development. 3. During metamorphosis the thoracic FLI neurons shift their position from ventrolateral to mid-ventral position and their axons terminate and elaborate a highly immunoreactive dorsal neural sheath. 4. It is suggested that the dorsal neural sheath may function as a neurohaemal organ from which FMRFamide-like substances may be released into the haemolymph to act as neurohormones.     

Immunocytochemical mapping of FMRFamide-like peptides in the argasid tick Ornithodoros parkeri and the ixodid tick Dermacentor variabilis

FMRFamide-like immunoreactivity was studied in the argasid tick Ornithodoros parkeri and the ixodid tick Dermacentor variabilis using immunocytochemistry based on the peroxidase-antigeroxidase method. FMRFamide-like immunoreactive cells are widely distributed in various regions of the tick synganglion including protocerebral, cheliceral, stomodeal, palpal, pedal I–IV, and opisthosomal regions in both species. However, there is one layer of immunoreactive cells located on the dorsal surface of the postoesophageal part of the synganglion that is found only in D. variabilis. Besides the immunoreactivity within the cell body and its axons, the neuropile and the neural lamella (the extracellular sheath of the synganglion) are rich in immunoreactive materials. Some coxal muscles are innervated by the FMRFamide-like immunoreactive processes of the nerve from the pedal ganglion.     

Localization of leucokinin-like immunoreactive neurons and their metamorphic changes in the ventral ganglion of the fly,Sarcophaga bullata

The distribution of leucokinin I-like immunoreactive neurons in the ventral ganglion of the fly Sarcophaga bullata was examined by indirect immunofluorescence. In the larval ventral ganglion there are seven pairs of large, highly immunoreactive neurons distributed ventrolaterally as bilateral pairs in abdominal neuromeres 1–7. During metamorphosis, the seven pairs of larval immunoreactive neurons survive and three additional pairs of immunoreactive neurons appear within the condensed abdominal ganglion, bringing the total number of immunoreactive neurons to 10 pairs. It is suggested that the neuropeptide from the newly formed three pairs of leucokinin-like immunoreactive neurons may have some unique function in the life of the adult insect.     

Detection of FMRFamide-like immunoreactivities in the sea scallopPlacopecten magellanicus by immunohistochemistry and Western blot analysis

FMRFamide-like immunoreactivity was detected histochemically in the sea scallopPlacopecten magellanicus. Most immunoreactivity was concentrated in the cerebral, pedal, and parietovisceral ganglia, particularly in the cortical cell bodies and in their fibers which extend into the central neuropile. Whole-mount immunofluorescence studies were used to localize concentrations of immunoreactive cells on the dorsal and ventral surfaces of each ganglion. Immunoreactivity was also detected in nerves emanating from the ganglia. Strong immunoreactivity was localized in peripheral organs, including the gut and gills of juvenile and adult scallops. Weak immunoreactivity was detected in the gonads, heart, and adductor muscle of the adults. A broad FMRFamide-like immunoreactive band of 2.5–8.2 kDa was detected by Western blotting of acetone extracts of the parietovisceral ganglia. In the presence of protease inhibitors, two FMRFamide-like immunoreactive bands (7.2–8.2 kDa and >17 kDa) were obtained. Neither of these bands comigrated with the FMRFamide standard. It is concluded that peptides of the FMRFamide family are probably regulators of numerous central and peripheral functions inP. magellanicus.     

FMRfamide-like immunoreactivity in the ventral nerve cord of the larval eastern spruce budworm,Choristoneura fumiferana (clemens) (Lepidoptera : Tortricidae)

Distribution of FMRFamide-like immunoreactivity was examined in the larval ventral nerve cord of the eastern spruce budworm, Choristoneura fumiferana (Lepidoptera : Tortricidae). Indirect immunofluorescent methods revealed the existence of 3 groups of FLI neurons in each ganglion. The neurons are distributed in a bilaterally symmetrical fashion at the anterodorsal, midlateral and posteroventral regions of the ganglia. There are 4 FMRFamide-like immunoreactive fiber tracts on the dorsal surface of the ganglia to which the anterodorsal FLI neurons project ipsilaterally, while the midlateral pair projects both ipsi-, and contralaterally. The last abdominal ganglion (AG8) has 4 additional pairs of FLI neurons; and axons from some of these extend into the median abdominal nerve, which suggests some role for this neuropeptide in the control of posterior structures of the larva.     

FMRFamide-related peptides in the gut of Locusta migratoria L.: a comprehensive map and developmental profile

The gut tissues and associated nervous system of the African migratory locust, Locusta migratoria, were found to contain FMRFamide-like immunoreactive (FLI) material throughout the five larval instars and 2 weeks into the adult stage in both males and females. FMRFamide-like immunoreactivity associated with the locust gut was described using camera lucida techniques. FMRFamide-like immunoreactivity is observed in the frontal connectives, recurrent nerve, and oesophageal nerves; projections from the ingluvial ganglion onto the anterior midgut, and from the proctodeal nerve onto the hindgut and posterior midgut; in the neuropils of the frontal ganglion, hypocerebral ganglion and ingluvial ganglia; 30 cell bodies in the frontal ganglion; multipolar sensory cells on the foregut; and endocrine-like cells in the gastric caecae and midgut. Radioimmunoassay (RIA) was used to determine the quantities of FLI material in foreguts, gastric caecae, anterior and posterior midguts, and hindgut of first-fifth instar larvae, 1-3- and 14-17-day male and female adult locusts. As expected, as the tissue size (assessed by total protein content) increases, so does the amount of FLI material in each tissue. Normalizing for tissue size reveals significant differences in FLI content among the stages for each tissue tested. Reversed phase-high pressure liquid chromatography (RP-HPLC) followed by RIA has identified four groups of FLI fractions present in the gut, and different members of these groups are present in the various gut tissues.     

Distribution of FMRFamide-like immunoreactivity in the brain and suboesophageal ganglion of the sphinx mothManduca sexta and colocalization with SCPB-, BPP-, and GABA-like immunoreactivity

Summary Using an antiserum against the tetrapeptide FMRFamide, we have studied the distribution of FMRFamide-like substances in the brain and suboesophageal ganglion of the sphinx mothManduca sexta. More than 2000 neurons per hemisphere exhibit FMRFamide-like immunoreactivity. Most of these cells reside within the optic lobe. Particular types of FMRFamide-immunoreactive neurons can be identified. Among these are neurosecretory cells, putatively centrifugal neurons of the optic lobe, local interneurons of the antennal lobe, mushroom-body Kenyon cells, and small-field neurons of the central complex. In the suboesophageal ganglion, groups of ventral midline neurons exhibit FMRFamide-like immunoreactivity. Some of these cells have axons in the maxillary nerves and apparently give rise to FMRFamide-immunoreactive terminals in the sheath of the suboesophageal ganglion and the maxillary nerves. In local interneurons of the antennal lobe and a particular group of protocerebral neurons, FMRFamide-like immunoreactivity is colocalized with GABA-like immunoreactivity. This suggests that FMRFamide-like peptides may be cotransmitters of these putatively GABAergic interneurons. All FMRFamide-immunoreactive neurons are, furthermore, immunoreactive with an antiserum against bovine pancreatic polypeptide, and the vast majority is also immunoreactive with an antibody against the molluscan small cardioactive peptide SCP_B. Therefore, it is possible that more than one peptide is localized within many FMRFamide-immunoreactive neurons. The results suggest that FMRFamide-related peptides are widespread within the nervous system ofM. sexta and might function as neurohormones and neurotransmitters in a variety of neuronal cell types.Abbreviations AL antennal lobe - BPPLI bovine pancreatic polypeptide-like immunoreactivity - FLI FMRFamide-like immunoreactivity - GLI GABA-like immunoreactivity - NSC neurosecretory cell - SCP _B LI small cardioactive peptide_B-like immunoreactivity - SLI serotonin-like immunoreactivity - SOG suboesophageal ganglion     

Stomatogastric nervous system of Galleria mellonella L. (Lepidoptera : Pyralidae): Changes during metamorphosis with special reference to FMRFamide neurons

Scanning electron microscopy and immunohistochemical staining for FMRFamide-like peptides revealed that the stomatogastric nervous system of Galleria mellonella (Lepidoptera : Pyralidae) includes 5 ganglia: the frontal ganglion with 4, the hypocerebral ganglion with 2, the ingluvial ganglion with 2–4, and each of the paired proventricular ganglia with 6–8 immunoreactive perikarya. Immunoreactivity was also found in axons to and within the corpora cardiaca, in the nerves connecting stomatogastric ganglia, as well as in 8 gastric nerves that extend along longitudinal midgut muscles. Adhesion of corpora cardiaca to the hypocerebral ganglion and partial merging and shortening of gastric nerves were the only conspicuous changes of the stomatogastric system that occurred during metamorphosis.     

The Morphology of the Stomodeal Nervous System in the Adult Dragon Flies Bradinopyga geminata and Orthetrum chrysis (Libellulidae)

The morphology of the stomodeal nervous system of the adult dragon flies Bradinopyga geminata and Orthetrum chrysis is described. No gastric ganglion or ganglion ingluviale has been found. Instead the oesophageal nerve forks near the junction of the proventriculus and the midgut. The two nerves run on either side of the midline as ingluvial nerves and enter the proventricular ganglionic masses. These ganglionic masses are connected by a transverse nerve, which has been called as the nervus transversus proventriculare. Both bipolar and multipolar types of sensory cells have been found over the surface of the crop. These cell bodies appear to be interconnected by connective tissue. Dendrites of these cells terminate on the longitudinal muscle fibres, surrounding the proventriculus and the midgut. The proximal processes of these cells enter the proventricular ganglionic mass. In methylene blue whole mounts they resemble the stretch receptors, hence it is quite probable that they play some role in the peristaltic movement of the gut. The corpora cardiaca lie dorsal to the pharynx and are connected to the brain by two pairs of nerves, the nervi corporis cardiaci (NCC I, NCC II). Unlike in other insects, the nerve connecting the corpora cardiaca with the corpora allata is slender and arises as a branch of the nerve, nervus corporis allati II. The corpora alata are spherical to ovoid in shape and lie ventral to the nerve cord. Anteriorly they are attached to the inner wall of the hypopharynx and posteriorly to the subesophageal ganglion by a pair of nerves, the nervi corporis allati II.     

Organization of the nervous system in Opisthorchis viverrini investigated by histochemical and immunohistochemical study

The structure and organization of the nervous system has been documented for various helminth parasites. However, the neuroanatomy of the carcinogenic liver fluke, Opisthorchis viverrini has not been described. This study therefore investigated the organization of the nervous system of this fluke using cholinesterase activity, aminergic and peptidergic (FMRFamide-like peptides) immunostaining to tag major neural elements. The nervous system, as detected by acetylcholinesterase (AchE) reaction, was similar in newly excysted metacercariae, migrating juveniles and adult parasites. In these stages, there were three pairs (dorsal, ventral and lateral) of bilaterally symmetrical longitudinal nerve cords and two cerebral ganglia. The ventral nerve cords and the cerebral ganglia were well-developed and exhibited strong AchE reactivity, as well as aminergic and FMRFamide-like immunoreactivity. Numerous immunoreactive nerve cell bodies were observed around the inner surface of the ventral sucker. Fine FMRFamide-like peptides immunopositive nerve fiber was rarely observed. Overall, the organization of the nervous system of O. viverrini is similar to other trematodes.     

Distribution of catecholamine-containing,serotonin-like and neuropeptide FMRFamide-like immunoreactive neurons and processes in the nervous system of the actinotroch larva ofPhoronis muelleri (Phoronida)

Summary Glyoxylic-acid-induced fluorescence of catecholamines and antibodies against serotonin and FMRFamide were used to study the distribution of putative neurotransmitters in the actinotroch larva ofPhoronis muelleri Selys-Longchamps, 1903. Catecholamines occur in the neuropile of the apical ganglion, in the longitudinal median epistome nerves, in the epistome marginal nerves, and in the nerve along the bases of the tentacles. The tentacles have laterofrontal and latero-abfrontal bundles of processes that form two minor nerves along the lateral ciliary band of the tentacles, and a medio-frontal bundle of processes. Monopolar cells are located on the ventro-lateral part of the mesosome. Processes are located along the posterior ciliary band and as a reticulum in the epidermis. Serotonin-like immunoreactive cells and processes are located in the apical ganglion, in the longitudinal median epistome nerves, and as a dorsal and ventral pair of bundles along the tentacle bases. Processes from the latter extend into the tentacles as the medioabfrontal processes. The latero-abfrontal processes form a minor nerve along the ciliary band. The dorsal bundles forms the major nerve ring along the tentacles and processes extend from it to the metasome. Processes are located along the posterior ciliary band. FMRFamide-like immunoreactive cells and processes are found in the apical ganglion, in the longitudinal median epistome nerves and as a pair of lateral epistome processes projecting towards the ring of tentacles. In the tentacles, a pair of latero-frontal processes are found; these form a minor nerve along the ciliary band. A band of cells can be seen along the tentacle ring.     

Development of the nervous system in Phoronopsis harmeri (Lophotrochozoa, Phoronida) reveals both deuterostome- and trochozoan-like features

Background

Inferences concerning the evolution of invertebrate nervous systems are often hampered by the lack of a solid data base for little known but phylogenetically crucial taxa. In order to contribute to the discussion concerning the ancestral neural pattern of the Lophotrochozoa (a major clade that includes a number of phyla that exhibit a ciliated larva in their life cycle), we investigated neurogenesis in Phoronopsis harmeri, a member of the poorly studied Phoronida, by using antibody staining against serotonin and FMRFamide in combination with confocal microscopy and 3D reconstruction software.

Results

The larva of Phoronopsis harmeri exhibits a highly complex nervous system, including an apical organ that consists of four different neural cell types, such as numerous serotonin-like immunoreactive flask-shaped cells. In addition, serotonin- and FMRFamide-like immunoreactive bi- or multipolar perikarya that give rise to a tentacular neurite bundle which innervates the postoral ciliated band are found. The preoral ciliated band is innervated by marginal serotonin-like as well as FMRFamide-like immunoreactive neurite bundles. The telotroch is innervated by two neurite bundles. The oral field is the most densely innervated area and contains ventral and ventro-lateral neurite bundles as well as several groups of perikarya. The digestive system is innervated by both serotonin- and FMRFamide-like immunoreactive neurites and perikarya. Importantly, older larvae of P. harmeri show a paired ventral neurite bundle with serial commissures and perikarya.

Conclusions

Serotonin-like flask-shaped cells such as the ones described herein for Phoronopsis harmeri are found in the majority of lophotrochozoan larvae and therefore most likely belong to the ground pattern of the last common lophotrochozoan ancestor. The finding of a transitory paired ventral neurite bundle with serially repeated commissures that disappears during metamorphosis suggests that such a structure was part of the ??ur-phoronid?? nervous system, but was lost in the adult stage, probably due to its acquired sessile benthic lifestyle.     

Distribution of FMRFamide-like immunoreactivity in the brain and neurohypophysis of the lamprey,Lampetra japonica

Summary Distribution of molluscan cardio-excitatory tetrapeptide Phe—Met—Arg—Phe—NH₂ (FMRFamide) was determined by means of immunohistochemistry in the brain and neurohypophysis of the lamprey, Lampetra japonica. Many FMRFamide-like immunoreactive neurons were found in the periventricular nuclear region and in a region near the mammillary recess. Neurons situated in the former region were larger. The immunoreactive cell groups were shown to be located at sites differing from those of the AF-positive cell groups. The fibers of immunoreactive neurons extended in all directions within the brain and towards the spinal cord, some reaching the third ventricle and capillaries. Thus, FMRFamide-like immunoreactive peptides appear to function as neurotransmitters or neuromodulators and possibly also as neurohormones. FMRFamide-like immunoreactive material was rarely observed in the posterior neurohypophysis (neural lobe), but was noted to be present to a limited extent in the caudal part of the anterior neurohypophysis (median eminence). It would thus follow that FMRFamide-like immunoreactive neurons may not necessarily be related to the hypothalamo-neural lobe system, but may possibly be associated with the hypothalamoadenohypophysial system. The pineal body showed no FMRFamide-like immunoreactivity.     

Distribution of FMRFamide-like immunoreactivity in the nervous system of the slug Limax maximus

Summary The distribution of FMRFamide-like immunoreactive neurons in the nervous system of the slug Limax maximus was studied using immunohistochemical methods. Approximately one thousand FMRFamide-like immunoreactive cell bodies were found in the central nervous system. Ranging between 15 m and 200 m in diameter, they were found in all 11 ganglia of the central nervous system. FMRFamide-like immunoreactive cell bodies were also found at peripheral locations on buccal nerve roots. FMRFamide-like immunoreactive nerve fibres were present in peripheral nerve roots and were distributed extensively throughout the neuropil and cell body regions of the central ganglia. They were also present in the connective tissue of the perineurium, forming an extensive network of varicose fibres. The large number, extensive distribution and great range in size of FMRFamide-like immunoreactive cell bodies and the wide distribution of immunoreactive fibres suggest that FMRFamide-like peptides might serve several different functions in the nervous system of the slug.     

Presence and distribution of immunoreactive and bioactive FMRFamide-like peptides in the nervous system of the horseshoe crab, Limulus polyphemus

FMRFamide immunoreactivity was detected in all regions of the Limulus nervous system, including the brain (6.5 +/- 0.6 pg FMRFamide/mg), cardiac ganglion (2.06 +/- 0.67 pg FMRFamide/mg), and ventral nerve cord (5.8 +/- 0.7 pg FMRFamide/mg). The distribution of immunoreactive FMRFamide (irFMRFamide) was mapped by immunofluorescence and the distribution corresponded to regional RIA data. A good proportion of the CNS and cardiac ganglion neuropile contained irFMRFamide, and fluorescent cell bodies were observed in several areas. High performance liquid chromatography (HPLC) was employed to separate and characterize the FMRFamide-like peptides from extracts of Limulus brains. HPLC fractions were analyzed using coincidental radioimmunoassay and bioassay (the radula protractor muscle of Busycon contrarium). There appear to be at least three FMRFamide-like peptides in the Limulus brain, including one similar to clam FMRFamide. FMRFamide acts on Limulus heart in a biphasic manner at relatively high concentrations (10(-5)M), but has no effect on the activity of the isolated ventral nerve cord. These data suggest that in Limulus FMRFamide-like peptides are acting as neurotransmitters, or neuromodulators.     

Glycogen in the proventriculus of the tsetse fly

Glycogen was detected in the proventriculus of the tsetse fly, Glossina morsitans morsitans, by ultrastructural, histochemical, and biochemical methods. This organ contained ten times or more glycogen on a dry weight basis than was found in the thoracic muscle. Proventriculi of male tsetse contained less glycogen than those of females belonging to the same age group and in teneral flies the amount of glycogen was about 50 per cent lower than in mature, fed flies of the same sex. Although the thoracic muscle of tsetse flies was considerably lower in glycogen than that of blowflies the amounts in the proventriculus of mature females of the two insect species were almost equal. It is suggested that this carbohydrate store may supply the energy required for secretory processes.     

FMRFamide-like immunoreactivity in the nervous system of hydra

Summary FMRFamide-like immunoreactivity has been localized in different parts of the hydra nervous system. Immunoreactivity occurs in nerve perikarya and processes in the ectoderm of the lower peduncle region near the basal disk, in the ectoderm of the hypostome and in the ectoderm of the tentacles. The immunoreactive nerve perikarya in the lower peduncle region form ganglion-like structures. Radioimmunoassays of extracts of hydra gave displacement curves parallel to standard FMRFamide and values of at least 8 pmol/gram wet weight of FMRFamide-like immunoreactivity. The immunoreactive material eluted from Sephadex G-50 in several components emerging shortly before or after position of authentic FMRFamide. The presence of FMRFamide-like material in coelenterates shows that this family of peptides is of great antiquity.     

Action and immunoreactivity of neuropeptides in the buccal neuromuscular system of a prosobranch mollusc,Rapana thomasiana

Summary In a prosobranch mollusc, Rapana thomasiana, the catch-relaxing peptide H-Ala-Met-Pro-Met-Leu-Arg-Leu-NH₂ (CARP) was found to depress the contraction of the radula protractor and retractor elicited by electrical stimulations. The action of CARP was in contrast to that of other neuropeptides, H-Phe-Met-Arg-Phe-NH₂ (FMRFamide) and H-Phe-Leu-Arg-Phe-NH₂ (FLRFamide), which enhanced the contraction of the radula protractor and retractor, respectively. By immunohistochemical examinations, FMRFamide-like immunoreactive neurons were found on the rostral side of the right buccal ganglion and the caudal side of the left ganglion, where some CARP-like immunoreactive neurons were also distributed, indicating a possible coexistence of FMRFamide and CARP. FMRFamide- and CARP-like immunoreactivities were also detected in the neuropile of buccal ganglia, radula nerves arising from the ganglia, and nerve fibers in the radula muscles. The present results suggest that FMRFamide- and CARP-like peptides are involved in the regulation of the contraction of the radula muscles.