FMRFamide-like Immunoreactivity Research Articles

Localization of fmrfamide-like immunoreactivity in the peripheral organs and its cross reaction with neuropeptide Y in the rat.

The molluscan cardioexcitatory peptide (FMRFamide) is a tetrapeptide. Neuropeptide Y (NPY) is a 36 amino acid peptide. Functionally, NPY is classified as a co-transmitter in the vasculatures of many organs and shows potent vasoconstriction. Coexistence of FMRFamide with NPY has been demonstrated in the central nervous system. The localization and distribution of NPY in the peripheral organs have been demonstrated mainly by radioimmunoassay. The localization and distribution, however, have not been investigated by immunohistochemistry. Therefore we present and compare the distribution of NPY- and FMRFamide-like immunoactivities in several peripheral organs of rats. Analysis of these data will reflect whether there is a cross reaction of FMRFamide with NPY antiserum or not. We have demonstrated both NPY- and FMRFamide-like nerve fibers in the vasculatures of the kidney, liver, pancreas, spleen, submandibular gland, lung and small intestine. The distribution pattern of these immuno-reactivities of the peripheral organs showed some extent of similarity. Radioimmunoassay indicated that FMRFamide possessed the ability to react with NPY-antiserum. This study demonstrated that the presence of FMRFamide immuno-reactivity in rat peripheral organs represents cross-reactivity of NPY with the FMRFamide anti serum. Such a result can be explained if antisera against NPY and FMRFamide recognize the carboxy-terminal sequence of -Arg-X-amide in the respective peptides.

Colocalization of octopamine and FMRFamide related peptide in identified heart projecting (DUM) neurones in the locust revealed by immunocytochemistry

Immunocytochemical techniques are employed to reveal colocalization of octopamine with FMRFamide related peptide in the locust ventral nervous system. In each unfused pregenital abdominal ganglia (A4-A6) there are 3 octapamine-like immunoreactive neurones. By combining intracellular Lucifer yellow staining with subsequent immunocytochemistry these are individually identified as the efferent dorsal unpaired median (DUM) neurones DUM-1 and DUM-2, which innervate abdominal tergal and respectively sternal skeletal muscles, and DUM heart-1, an FMRFamide-like immunoreactive neurone which projects to the heart and associated alary muscles. Colocalization of octopamine- and FMRFamide-like immunoreactivity in DUM heart-1 is verified by alternate staining of consecutive sections. With respect to locust ganglia, this investigation shows that colocalization of octopamine with an FMRFamide related peptide is restricted to a single DUM cell occuring in each abdominal ganglion 2–7, which most likely correponds to segmental homologues of DUM heart-1.

FMRFamide‐like activity in the female locust during vitellogenesis

The control of oviposition in the locust involves the expulsion of eggs from the lateral oviducts, a process believed to be under neurohormonal control. In this paper we have attempted to identify this putative hormone. Immunohistochemical staining of the brain retrocerebral complex and suboesophageal ganglion of Locusta migratoria with antiserum against FMRFamide revealed a number of FMRFamide-immunopositive cells. FMRFamide-like immunoreactivity was present in median neurosecretory cells and lateral neurosecretory cells of the protocerebrum. Other FMRFamide-immunoreactive cells were detected in the deutocerebrum and tritocerebrum. Immunoreactive cell processes were observed in the mushroom bodies, the central body, the optic lobes, and in the axon tracts leaving the pars intercerebralis and tritocerebrum. FMRFamide-like material was also seen in the circumoesophageal commissures. Further FMRFamide-like material was present in cell bodies of the suboesophageal ganglion. FMRFamide-like staining activity changed dramatically during the oviposition cycle in mature adult females. The median neurosecretory cells stained lightly immediately after oviposition and remained pale until the third day, when staining of perikarya and axon tracts increased. The staining intensity decreased on days 4 and 5. The titre of FMRFamide-like material in the hemolymph increased during the vitellogenic cycle but plummeted after oviposition. A single band of FMRFamide-like material was evident on immunoblot following sodium dodecyl sulphate-polyacrylamide gel electrophoresis of adult female hemolymph. The approximate molecular weight of this molecule was 8,000. Gel permeation chromatography of hemolymph revealed a FMRFamide-immunoreactive fraction with a molecular weight of 8,000. This fraction possessed myotropic activity when applied to the locust oviduct.(ABSTRACT TRUNCATED AT 250 WORDS)

Co-localization of peptides in the Brockmann bodies of the cod (Gadus morhua) and the rainbow trout (Oncorhynchus mykiss)

Endocrine cells exhibiting immunoreactivity to FMRFamide-like, LPLRFamide-like, neuropeptide Y(NPY)-like and peptide YY(PYY)-like peptides were found in the periphery of the Brockmann bodies of the cod, Gadus morhua, and rainbow trout, Oncorhynchus mykiss. No immunoreactivity or very weak labelling was found with antisera to pancreatic polypeptide (PP). Vasoactive intestinal polypeptide (VIP)-like immunoreactivity was found in nerve fibres, whereas labelling with VIP antiserum in endocrine cells disappeared after preincubation with nonimmune serum. There were always more immunoreactive cells in the rainbow trout than in the cod. No immunoreactivity could be seen with antisera to gastrin/cholecystokinin (CCK) or enkephalin. Double-labelling studies were performed to study the colocalization of the peptides in peripheral endocrine cells. Cells immunoreactive to NPY were also labelled with antisera to FMRFamide, LPLRFamide and PYY. The co-localization pattern of NPY varied; in some Brockmann bodies, a population of the immunoreactive cells showed co-localization and others contained NPY-like immunoreactivity only, whereas in other Brockmann bodies, all NPY-labelled cells also contained FMRFamide-like, LPLRFamide-like and PYY-like immunoreactivity. Cells immunoreactive to PYY similarly contained FMRFamide-like, LPLRFamide-like and NPY-like immunoreactivity, comparable to the patterns observed with NPY. Glucagon-like immunoreactivity was found at the periphery of the Brockmann bodies. A subpopulation of the glucagon-containing cells contained NPY-like immunoreactivity. PYY-like immunoreactivity was also found co-localized with glucagon-like immunoreactivity, as were FMRFamide-like and LPLRFamide-like immunoreactivity. Therefore, either NPY-like and PYY-like immunoreactivity together with FMRFamide-like and LPLRFamide-like immunoreactivity occur in the same endocrine cells of the Brockmann body of the cod and rainbow trout, or a hybrid NPY/PYY-like peptide recognized by both NPY and PYY antisera is present in the Brockmann body.

Organogenesis in the leech: development of nephridia, bladders and their innervation.

The formation of the definitive excretory system (nephridium and bladder complex) in Hirudo medicinalis during the last two thirds of embryonic development was observed with light- and electron microscopy, immunocytochemistry, and nuclear labeling. In jawed leeches, two excretory systems develop and function successively. The nephridia of the cryptolarva are associated with the larval sac and persist until the definitive nephridia are sufficiently developed to be functional. Development of the definitive excretory system begins with the differentiation of the (ectodermal) bladder and urethra. The cells from which they arise incorporate bacteria and are thereby recognizable at day 8. The (mesodermal) urine-forming tissues of the nephridium (canalicular cells and central canal cells) appear a day later. By day 17, the nephridia are in contact with the outlet region and structurally able to function. Each nephridium is individually innervated by a peripheral neuron, the nephridial nerve cell, which expresses FMR Famide-like immunoreactivity and begins growing into the nephridium on day 11. Organogenesis of the leech nephridium is compared with the formation of excretory organs in other species. The temporal correlation of innervation and the development of the transporting cells is discussed.

Localization and differential expression of FMRFamide-like immunoreactivity in the nematode Ascaris suum.

By immunocytochemical and immunohistochemical methods, FMRFamide-like immunoreactivity (FLI) was localized to many neurons and processes in the Ascaris nervous system, including the head, tail, and lateral lines. Some of these cells were identified; they included sensory neurons, interneurons, and motor neurons. FLI was also present in the pharyngeal neurons and in their varicosities near the surface of the pharynx. By HPLC analysis of extracts, only a subset of the FMRFamide-like peptides (FLPs) expressed in Ascaris heads, and heads from which the pharynx had been removed, were expressed in the pharynx. Furthermore, FLPs appeared to be differentially expressed in female heads and tails and male heads and tails. Acetone and acid methanol differentially extracted subforms of FLI from Ascaris heads and from C. elegans.

The pulsatile appearance of FMRFamide-related peptides in the haemolymph and loss of FMRFamide-like immunoreactivity from neurohaemal areas of Rhodnius prolixus following a blood meal

The release of FMRFamide-related peptides (FaRPs) from nervous tissue and corpus cardiacum/dorsal vessel and their appearance in the haemolymph of Rhodnius prolixus after a blood meal was investigated using immunohistochemistry, RIA and HPLC. Release of FaRPs was indicated by a decrease in the intensity of FMRFamide-like immunoreactive staining of neurohaemal areas associated with the retrocerebral complex and abdominal nerves, and confirmed, using RIA, by the tissue-specific decreases and appearance of FaRPs in the haemolymph. Titres of FaRPs in the haemolymph rose and fell in a pulse-like manner at fairly fixed times during the first 12 h after feeding (period of observation). Titres in the haemolymph rose from 0.88 nM to post-feeding pulse titres which ranged from 2.4 to 19.6 nM. The highest titres found in the haemolymph occurred at about 3, 6 and 10 h after feeding. Results from HPLC and RIA indicate that FaRPs may be synthesized in the nervous system and then released into the haemolymph, possibly as a mixture, which might subsequently affect various physiological processes involved in digestion and development.

Pigment‐dispersing hormone‐like peptide in the nervous system of the flies Phormia and Drosophila: Immunocytochemistry and partial characterization

beta-pigment-dispersing hormone (beta-PDH) isolated from the fiddler crab (Rao et al., '85) is a member of an octadecapeptide family of neuropeptides common to arthropods. Whereas earlier studies of these peptides in insects were limited to orthopterans, this investigation focuses on dipteran flies. Extracts of heads from the blowfly Phormia terraenovae were assessed in a fiddler crab bioassay for PDH activity. Immunocytochemistry, dose-response curves, gel filtration chromatography and reversed-phase HPLC, combined with bioassay and enzyme-linked immunosorbent assay (ELISA), indicate the presence of PDH-like peptide in the blowfly. Immunocytochemical mapping of PDH-like immunoreactive (PDHLI) neurons was performed for the entire nervous systems of Phormia and the fruitfly Drosophila with a beta-PDH antiserum. In the cephalic ganglion (brain, optic lobe and subesophageal ganglion) PDHLI cell bodies could be detected (34 in Phormia and 16 in Drosophila). In both species, each hemisphere contains 8 PDHLI cell bodies in the optic lobes. These innervate the optic lobe neuropils bilaterally. In Phormia, another set of 8 cell bodies are located in each of the lateral neurosecretory cell groups in the superior protocerebrum. These neurons send axons to the corpora cardiaca-hypocerebral ganglion complex and to portions of the foregut. In contrast, only the optic lobe neurons display immunoreactivity in Drosophila. Except for the optic lobes, PDHLI processes are distributed only in nonglomerular neurophils of the brain of both species. In the fused thoracico-abdominal ganglia of Phormia, 28 PDHLI cell bodies were found (only six were found in Drosophila). In both species, six abdominal PDHLI neurons are efferents with axons innervating the hindgut. We also found that some of the PDHLI neurons in the Phormia brain and abdominal ganglion contain colocalized FMRFamide-like immunoreactivity. Since the flies studied here do not display hormonally controlled, fast pigment migrations, the PDH-like peptide may have a role as neurotransmitter or neuromodulator in the central nervous system, especially in the visual system, and a regulatory role in the stomatogastric system and the hind-gut.

Distribution and partial characterization of FMRFamide-like peptides in the horseshoe crab, Limulus polyphemus

1. FMRFamide-related peptides are widely distributed in the horseshoe crab Limulus polyphemus and may have a role in cardioregulation. 2. The distribution of FMRFamide-like immunoreactivity in Limulus was determined by radioimmunoassay. The ventral nerve cord (12.6 ± 3.3 pg/mg) and prosomal CNS (11.9 ± 1.7 pg/mg) contained the highest quantities of iR-FMRFamide. Lesser amounts of iR-FMRFamide were detected in the cardiac ganglion (4.6 ± 2.4 pg/mg) and segmental cardiac nerves 9 and 10 (4.0 ± 2.0 pg/mg). Immunoreactive FMRFamide was detected in high concentrations in the branchial nerves (11.2 ± 2.6 pg/mg). Other peripheral nerves or tissues contained lower quantities of immunoreactive FMRFamide. 3. Limulus prosomal CNS, cardiac ganglion and ventral nerve cord extracts were used to isolate FMRFamide-related peptides. A high molecular weight immunoreactive factor was detected on Sephadex G-15. This factor was purified further with Sep-Pak C18 and ion exchange chromatographies. With ion exchange, one peak of immunoreactive FMRFamide was isolated on a sharp gradient of ammonium acetate and increased pH. 4. With reverse phase HPLC, two peaks of immunoreactivity were detected in partially purified material. In the prosomal CNS and cardiac ganglion extracts, the first peak of activity exhibited an elution time similar to that of FMRFamide, while a more hydrophobic peak eluted with pQDPFLRFamide. FMRFamide-like immunoreactivity in the ventral nerve cord extracts separated into a peak eluting shortly before FMRFamide and a second peak eluting with pQDPFLRFamide. 5. Synthetic FMRFamide and pQDPFLRFamide were applied to the Limulus neurogenic heart preparation. FMRFamide had little effect on the cardiac rhythm, while application of pQDPFLRFamide resulted in marked increases in the rate, and to a lesser extent the strength, of heart contractions. 6. These findings suggest a cardioregulatory function for an endogenous FMRFamide-like peptide in Limulus in addition to other physiological roles.

Colocalization of neuropeptide Y (NPY)-like and FMRFamide-like immunoreactivities in the brain of the Atlantic salmon (Salmo salar).

The colocalization of the peptides neuropeptide Y (NPY) and Phe-Met-Arg-Phe-NH2 (FMRFamide) in the brain of the Atlantic salmon was investigated with double immunofluorescence labeling and peroxidase-antiperoxidase immunocytochemical techniques. Colocalization of NPY-like and FMRF amide-like immunoreactivities was observed in neuronal cell bodies and fibers in four brain regions: in the lateral and commissural nuclei of the area ventralis telencephali, in the nucleus ventromedialis thalami, in the laminar nucleus of the mesencephalic tegmentum, and in a group of small neurons situated among the large catecholaminergic neurons in the isthmal region of the brainstem. All cell bodies in these nuclei were immunoreactive to both NPY and FMRF. We consistently observed larger numbers of FMRF-immunoreactive than NPY-immunoreactive fibers. In the nucleus ventromedialis thalami NPY- and FMRFamide-like immunoreactivities were colocalized in cerebrospinal fluid (CSF)-contacting neurons. NPY-immunoreactive, but not FMRF-immunoreactive, neurons were found in the stratum periventriculare of the optic tectum, and at the ventral border of the nucleus habenularis (adjacent to the nucleus dorsolateralis thalami). Neurons belonging to the nucleus of the nervus terminalis were FMRF-immunoreactive but not NPY-immunoreactive. The differential labeling indicates, as do our cross-absorption experiments, that the NPY and FMRFamide antisera recognize different epitopes. Thus, it is probable that NPY-like and FMRF amide-like substances occur in the same neurons in some brain regions.

Ultrastructure and immunocytochemistry of the nervous system of the larvae ofLingula anatina andGlottidia sp. (Brachiopoda)

Planktotrophic brachiopod larvae ofGlottidia sp. have been investigated for the occurrence of glyoxylic acid induced fluorescence in catecholamines (CA), and serotonin-like (5-HT) and neuropeptide FMRFamidelike (FMRFamide) immunoreactivity (ir). The location of CA, 5-HT-ir and FMRFamide-ir cells and processes were compared with the location of neurons and nerve processes found by transmission electron microscopy. The apical ganglion contains 5-HT-ir and FMRFamideir cells and processes and CA processes. From the dorsal part of the apical ganglion extend dorsal 5-HT-ir and FMRFamide-ir processes; from the nine pairs of tentacles stage (9. pt) they project to the ventral ganglion. These dorsal lophophore processes follow themusculus lophophoralis and them. brachialis. The 5-HT-ir and some of the FMRFamide-ir processes project along the muscles to the tentacles. From the ventral part of the apical ganglion extend CA, 5-HT-ir and FMRFamide-ir processes which follow the ciliary band of the lophophore and project to the tentacles. An intense band of CA processes was also observed in the lophophore, but the dorsal/ventral location could not be ascertained. The ventral ganglion contains 5-HT-ir and FMRFamide-ir cells which project either caudally on the metasome or rostrally as part of the dorsal lophophore processes. The neuropil of the ventral ganglion contains CA, 5-HT-ir and FMRFamide-ir processes. The nervous system of the planktotrophic brachiopod larvae seems to consist of a ventral lophophore system innervating the ciliary bands and a dorsal lophophore system including the ventral ganglion innervating the body musculature. The latter system develops later in ontogeny and is regarded as a specialization due to the presence of shells and associated musculature. The former system is regarded as homologous with the nervous system of actinotroch larvae (Phoronida) and planktotrophic larvae of the echinoderms.

FMRFamide-like immunoreactivity in the brain of the Pacific hagfish, Eptatretus stouti (Myxinoidea).

The distribution of FMRFamide-like immunoreactivity was investigated in the brain of a myxinoid, the Pacific hagfish, Eptatretus stouti, by means of immunocytochemistry. In the forebrain, labelled cell bodies occurred in the infundibular nucleus of the hypothalamus and some closely adjacent nuclei. Labelled fibers formed a diffuse network in the forebrain, but there was no evidence for the presence of intracerebral ganglionic cells of the terminal nerve or a central projection of the terminal nerve. In the hindbrain, a group of labelled cells was found in the trigeminal sensory nucleus. A distinct terminal arborization occurred in the ventrally adjacent nucleus A of Kusunoki and around the nuclei of the branchial motor column. These findings suggest that FMRFamide may play a role in the central control of branchiomotor activity.

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.

Localization of FMRFamide-like immunoreactivity in the larval midgut of the fly, Sarcophaga bullata

1. Distribution of FMRFamide-like immunoreactivity was examined in the larval gut of the fly Sarcophaga bullata. 2. Peroxidase-antiperoxidase and indirect immunofluorescent methods revealed immunoreactivity in the proventriculus and parts of the anterior midgut. 3. The outer wall of the proventriculus was innervated by 12–16 FLI neurons of hypocerebral ganglion. 4. In the anterior midgut, FLI cells were randomly distributed between the muscle fibers and among the columnar epithelial cells of the midgut. 5. The organization, distribution pattern and the association of FLI cells with midgut epithelium suggest that FMRFamide-like peptides may regulate feeding and peristalsis in this insect.

FMRFamide-like immunoreactivity in the brain and pituitary of the goldfish, Carassius auratus

The distribution of FMRFamide-like immunoreactivity was determined in the brain and the pituitary of the goldfish, Carassius auratus. Immunoreactive perikarya were observed in the olfactory nerve, nucleus entopeduncularis, nucleus anterioris periventricularis, nucleus posterioris periventricularis, lateral part of the nucleus lateralis tuberis pars posterioris, midbrain tegmentum, and medulla oblongata. Immunoreactive fibers were widely distributed in the brain, in particular in the ventral telencephalon and the hypothalamus. A few immunoreactive nerve fibers were observed in the pituitary. The findings are discussed in relation to male sexual behavior and the involvement of FMRFamide-like peptide in pituitary functions in the goldfish.

Peptidergic regulation of the Limulus midgut.

1. The morphology and innervation of the midgut (intestine) in the horseshoe crab, Limulus polyphemus was investigated. The organization of this tissue was examined with routine histology. Radioimmunoassay, immunohistochemistry and high performance liquid chromatography were employed to detect, localize and identify peptidergic innervation of the midgut. The actions of synthetic and native proctolin-like and FMRFamide-like peptides were compared on the isolated midgut preparation. 2. Levels of proctolin and FMRFamide were determined in extracts of Limulus midgut tissue using radioimmunoassay. High levels of proctolin-like immunoreactivity (69.5 +/- 11.3 ng/g) were detected, while levels of FMRFamide-like immunoreactivity (0.8 +/- 0.2 ng/g) were less. Proctolin levels were equally distributed, while the levels of FMRFamide-like immunoreactivity exhibited an anterior bias. 3. Proctolin- and FMRFamide-like immunoreactivities in the Limulus midgut were localized with immunohistochemistry. Proctolin- and FMRFamide-immunoreactive elements were detected in intestinal nerve branches and individual fibers running along the surface of the midgut in whole-mount preparations. In sectioned tissue, staining for these peptides was observed throughout the midgut, typically associated with muscle bands and fibers. Only a few immunoreactive cell bodies were observed. 4. Proctolin, and several FMRFamide-like peptides produced distinct and opposing actions on the isolated Limulus midgut preparation. Proctolin elicited contracture and rhythmic contractions of this tissue, while FMRFamide and N-terminally extended analogs of FLRFamide relaxed gut tension. FMRFamide-like peptides partially reversed the excitatory actions of proctolin. 5. Proctolin- and FMRFamide-like peptides in Limulus midgut extracts were partially characterized with high performance liquid chromatography. One peak of proctolin-like activity was detected on a linear gradient of 18 to 31.5% acetonitrile. The native proctolin-like peptide produced excitatory actions on the isolated midgut preparation which were indistinguishable from those produced by synthetic proctolin. Several peaks of FMRFamide-like bioactivity (Busycon radula protractor muscle assay) were detected with a linear gradient of 5 to 30% acetonitrile. Fractions from two distinct peaks produced FMRFamide-like inhibitory effects on the isolated Limulus midgut preparation. These findings suggest a role for proctolin-like and FMRFamide-like peptides as regulators of intestinal motility in Limulus.

Characterization of Two Novel Neuropeptides From the Sea Cucumber Holothuria glaberrima.

Two peptides were purified from intestinal extracts of a sea cucumber, Holothuria glaberrima, by high pressure liquid chromatography (HPLC). The peptides were detected by a radioimmunoassay (RIA) based on an antiserum raised to the molluscan peptide, pGlu-Asp-Pro-Phe-Leu-Arg-Phe-NH2 (pQDPFLRFamide). Automated sequencing and mass spectrometry indicate that the isolated peptides are: Gly-Phe-Ser-Lys-Leu-Tyr-Phe-NH2 (GFSKLYFamide) and Ser-Gly-Tyr-Ser-Val-Leu-Tyr-Phe-NH2 (SGYSVLYFamide). These are the first peptides to have been isolated from a member of the echinoderm class Holothuroidea. The antiserum used in the RIA of the peptides was also employed in localizing immunoreactive nerve cells and fibers in the intestine of H. glaberrima. The immunohistochemical results suggest that these peptides might be responsible for the FMRFamide-like immunoreactivity reported earlier. Sequence similarities between GFSKLYFamide, SGYSVLYFamide, and a pair of peptides previously isolated from starfish lead us to propose that all four molecules are members of a family of peptides acting as neurotransmitters in echinoderms.

Localization of FMRFamide-like peptides in Caenorhabditis elegans.

The neuropeptide FMRFamide (Phe-Met-Arg-Phe-NH2) is a member of a large family of related peptides that have been found throughout the animal kingdom. By using an antiserum specific for the Arg-Phe-NH2 moiety, we have found that about 10% of the neurons in the nematode Caenorhabditis elegans are immunoreactive. Most of these neurons, which include sensory, motor, and interneurons, were identified on the basis of their number, position, and projection pattern and by analysis of characterized mutants. Neurons that were immunoreactive in hermaphrodite animals were generally also found in males, but each sex had, in addition, sex-specific immunoreactive cells. Staining of hermaphrodite animals from different larval stages suggests that the onset of FMRFamide-like expression is differentially regulated among the cells. We have found a possible neuromodulatory role for the related peptide FLRFamide (Phe-Leu-Arg-Phe-NH2). In an egg-laying assay, FLRFamide by itself was not active but could potentiate a serotonin effect. The FMRFamide-like immunoreactivity was also used as a marker to examine the differentiation of cells that normally undergo programmed cell death. Cells that are destined to die in the Pn.a lineages appear to differentiate and adopt the fate of lineally equivalent cells before cell death.

Colocalization and differential expression of PBAN‐ and FMRFamide‐like immunoreactivity in the subesophageal ganglion of Helicoverpa zea (Lepidoptera: Noctuidae) during development

AbstractPheromone biosynthesis activating neuropeptide (PBAN) stimulates sex pheromone production in several species of moths. We have used an antiserum to PBAN to map the distribution of PBAN‐like immunoreactivity (PLI) in the subesophageal ganglion (SEG) of the larval and pupal stages of the corn earworm, Helicoverpa zea, and compared this distribution with that of the adult. The distribution of PLI within the SEG of larvae and pupae was quite similar to that found in adults, suggesting a function for PBAN other than the stimulation of pheromone biosynthesis. In all developmental stages studied, three groups of nerve cells in the SEG, and their projections, contained PLI. In adults and larvae, most of the cells containing PLI also had FMRFamide‐like immunoreactivity (FLI). In pupae, however, a number of cells which appeared to have PLI and FLI in both larvae and adults, did not contain andy detectable FLI, while the PLI appeared unchanged. The FLI returns to these cells during adult development. These immunocytochemical observations were corroborated by quantifying PLI and FLI by competitive ELISA; the level of extractable FLI in pupae was about 25% of that found in larvae, while PLI levels were unchanged. © 1992 Wiley‐Liss, Inc.

Distribution of FMRFamide-like immunoreactivity in the forebrain of the catfish, Clarias batrachus (Linn.)

The anatomical distribution of FMRFamide-like immunoreactivity in the forebrain and pituitary of the catfish, Clarias batrachus, was investigated. Immunoreactive cells were observed in the ganglion cells of the nervus terminalis (NT) and in the medial olfactory tracts. In the preoptic area, FMRFamide-containing perikarya were restricted to the lateral preoptic area, paraventricular subdivision of the nucleus preopticus, nucleus suprachiasmaticus and nucleus preopticus periventricularis posterior. In the postoptic area, some cells of the nucleus postopticus lateralis and nucleus of the horizontal commissure showed moderate immunoreactivity. In the tuberal area, immunoreactivity was observed in few cells of the nucleus hypothalamicus ventralis and nucleus arcuatus hypothalamicus (NAH). Nucleus ventromedialis thalami was the only thalamic nucleus with FMRFamide immunoreactivity. Immunoreactive processes were traceable from the NT through the medial as well as lateral olfactory tracts into the telencephalon and the area ventralis telencephali pars supracommissuralis (Vs). Further caudally, the immunoreactive fibers could be traced into discrete areas, including habenular and posterior commissures, neurohypophysis and pituitary; isolated fibers were also observed in the pineal stalk. A loose network of immunoreactive processes was observed in the olfactory bulbs and the entire telecephalon, with higher densities in some areas, including Vs. A dense plexus of immunoreactive fibers was seen in the pre- and postoptic areas and around the paraventricular organ, while relatively few were observed in the thalamus. A high concentration of fiber terminals was found in the caudal tuberal area.