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Eve Marder - One of the best experts on this subject based on the ideXlab platform.
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The Crustacean Stomatogastric Nervous System
Handbook of Brain Microcircuits, 2017Co-Authors: Eve MarderAbstract:The crustacean Stomatogastric Nervous System has become one of the premier preparations used for the study of the mechanisms underlying the generation of rhythmic motor patterns. The Stomatogastric ganglion (STG) contains about 30 neurons, most of which are motor neurons that innervate more than 40 sets of striated muscles that move the animal’s stomach. Descending projection neurons from the two commissural ganglia (CoGs) and the single oesophageal ganglion (OG) are important for the generation of the motor patterns produced by the STG. Identified sensory neurons project either into the CoGs to activate descending modulatory neurons, or directly into the STG.
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Consequences of acute and long-term removal of neuromodulatory input on the episodic gastric rhythm of the crab, Cancer borealis
Journal of neurophysiology, 2015Co-Authors: Albert W. Hamood, Eve MarderAbstract:For decades, the episodic gastric rhythm of the crustacean Stomatogastric Nervous System (STNS) has served as an important model System for understanding the generation of rhythmic motor behaviors....
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How can motor Systems retain performance over a wide temperature range? Lessons from the crustacean Stomatogastric Nervous System
Journal of comparative physiology. A Neuroethology sensory neural and behavioral physiology, 2015Co-Authors: Eve Marder, Marie L. Goeritz, Sara A. Haddad, Philipp Rosenbaum, Tilman J. KisperskyAbstract:Marine invertebrates, such as lobsters and crabs, deal with a widely and wildly fluctuating temperature environment. Here, we describe the effects of changing temperature on the motor patterns generated by the Stomatogastric Nervous System of the crab, Cancer borealis. Over a broad range of “permissive” temperatures, the pyloric rhythm increases in frequency but maintains its characteristic phase relationships. Nonetheless, at more extreme high temperatures, the normal triphasic pyloric rhythm breaks down, or “crashes”. We present both experimental and computational approaches to understanding the stability of both single neurons and networks to temperature perturbations, and discuss data that shows that the “crash” temperatures themselves may be environmentally regulated. These approaches provide insight into how the Nervous System can be stable to a global perturbation, such as temperature, in spite of the fact that all biological processes are temperature dependent.
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Distribution and physiological effects of B-type allatostatins (myoinhibitory peptides, MIPs) in the Stomatogastric Nervous System of the crab Cancer borealis.
The Journal of comparative neurology, 2011Co-Authors: Theresa M. Szabo, Ruibing Chen, Marie L. Goeritz, Ryan T. Maloney, Lamont S. Tang, Eve MarderAbstract:The crustacean Stomatogastric ganglion (STG) is modulated by a large number of amines and neuropeptides that are found in descending pathways from anterior ganglia or reach the STG via the hemolymph. Among these are the allatostatin (AST) B types, also known as myoinhibitory peptides (MIPs). We used mass spectrometry to determine the sequences of nine members of the AST-B family of peptides that were found in the Stomatogastric Nervous System of the crab Cancer borealis. We raised an antibody against Cancer borealis allatostatin-B1 (CbAST-B1; VPNDWAHFRGSWa) and used it to map the distribution of CbAST-B1-like immunoreactivity (-LI) in the Stomatogastric Nervous System. CbAST-B1-LI was found in neurons and neuropil in the commissural ganglia (CoGs), in somata in the esophageal ganglion (OG), in fibers in the Stomatogastric nerve (stn), and in neuropilar processes in the STG. CbAST-B1-LI was blocked by preincubation with 10−6 M CbAST-B1 and was partially blocked by lower concentrations. Electrophysiological recordings of the effects of CbAST-B1, CbAST-B2, and CbAST-B3 on the pyloric rhythm of the STG showed that all three peptides inhibited the pyloric rhythm in a state-dependent manner. Specifically, all three peptides at 10−8 M significantly decreased the frequency of the pyloric rhythm when the initial frequency of the pyloric rhythm was below 0.6 Hz. These data suggest important neuromodulatory roles for the CbAST-B family in the Stomatogastric Nervous System. J. Comp. Neurol. 519:2658–2676, 2011. © 2011 Wiley-Liss, Inc.
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Spectral analyses reveal the presence of adult-like activity in the embryonic Stomatogastric motor patterns of the lobster, Homarus americanus.
Journal of neurophysiology, 2008Co-Authors: Kristina J. Rehm, Adam L. Taylor, Stefan R. Pulver, Eve MarderAbstract:The Stomatogastric Nervous System (STNS) of the embryonic lobster is rhythmically active prior to hatching, before the network is needed for feeding. In the adult lobster, two rhythms are typically...
Andrew E Christie - One of the best experts on this subject based on the ideXlab platform.
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Non-amidated and amidated members of the C-type allatostatin (AST-C) family are differentially distributed in the Stomatogastric Nervous System of the American lobster, Homarus americanus
Invertebrate Neuroscience, 2018Co-Authors: Andrew E Christie, Alexandra Miller, Rebecca Fernandez, Evyn S. Dickinson, Audrey Jordan, Jessica Kohn, Mina C. Youn, Patsy S. DickinsonAbstract:The crustacean Stomatogastric Nervous System (STNS) is a well-known model for investigating neuropeptidergic control of rhythmic behavior. Among the peptides known to modulate the STNS are the C-type allatostatins (AST-Cs). In the lobster, Homarus americanus, three AST-Cs are known. Two of these, pQIRYHQCYFNPISCF (AST-C I) and GNGDGRLYWRCYFNAVSCF (AST-C III), have non-amidated C-termini, while the third, SYWKQCAFNAVSCFamide (AST-C II), is C-terminally amidated. Here, antibodies were generated against one of the non-amidated peptides (AST-C I) and against the amidated isoform (AST-C II). Specificity tests show that the AST-C I antibody cross-reacts with both AST-C I and AST-C III, but not AST-C II; the AST-C II antibody does not cross-react with either non-amidated peptide. Wholemount immunohistochemistry shows that both subclasses (non-amidated and amidated) of AST-C are distributed throughout the lobster STNS. Specifically, the antibody that cross-reacts with the two non-amidated peptides labels neuropil in the CoGs and the Stomatogastric ganglion (STG), axons in the superior esophageal (son) and Stomatogastric (stn) nerves, and ~ 14 somata in each commissural ganglion (CoG). The AST-C II-specific antibody labels neuropil in the CoGs, STG and at the junction of the sons and stn, axons in the sons and stn, ~ 42 somata in each CoG, and two somata in the STG. Double immunolabeling shows that, except for one soma in each CoG, the non-amidated and amidated peptides are present in distinct sets of neuronal profiles. The differential distributions of the two AST-C subclasses suggest that the two peptide groups are likely to serve different modulatory roles in the lobster STNS.
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Distinct or shared actions of peptide family isoforms: II. Multiple pyrokinins exert similar effects in the lobster Stomatogastric Nervous System.
Journal of Experimental Biology, 2015Co-Authors: Patsy S. Dickinson, Sienna C. Kurland, Brett O. Parker, Anirudh Sreekrishnan, Molly A. Kwiatkowski, Alex H. Williams, Alexandra B. Ysasi, Andrew E ChristieAbstract:Many neuropeptides are members of peptide families, with multiple structurally similar isoforms frequently found even within a single species. This raises the question of whether the individual peptides serve common or distinct functions. In the accompanying paper, we found high isoform specificity in the responses of the lobster ( Homarus americanus ) cardiac neuromuscular System to members of the pyrokinin peptide family: only one of five crustacean isoforms showed any bioactivity in the cardiac System. Because previous studies in other species had found little isoform specificity in pyrokinin actions, we examined the effects of the same five crustacean pyrokinins on the lobster Stomatogastric Nervous System (STNS). In contrast to our findings in the cardiac System, the effects of the five pyrokinin isoforms on the STNS were indistinguishable: they all activated or enhanced the gastric mill motor pattern, but did not alter the pyloric pattern. These results, in combination with those from the cardiac ganglion, suggest that members of a peptide family in the same species can be both isoform specific and highly promiscuous in their modulatory capacity. The mechanisms that underlie these differences in specificity have not yet been elucidated; one possible explanation, which has yet to be tested, is the presence and differential distribution of multiple receptors for members of this peptide family.
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Identification, physiological actions, and distribution of TPSGFLGMRamide: a novel tachykinin-related peptide from the midgut and Stomatogastric Nervous System of Cancer crabs.
Journal of neurochemistry, 2007Co-Authors: Elizabeth A. Stemmler, Patsy S. Dickinson, Braulio Peguero, Emily A. Bruns, Andrew E ChristieAbstract:In most invertebrates, multiple species-specific isoforms of tachykinin-related peptide (TRP) are common. In contrast, only a single conserved TRP isoform, APSGFLGMRamide, has been documented in decapod crustaceans, leading to the hypothesis that it is the sole TRP present in this arthropod order. Previous studies of crustacean TRPs have focused on neuronal tissue, but the recent demonstration of TRPs in midgut epithelial cells in Cancer species led us to question whether other TRPs are present in the gut, as is the case in insects. Using direct tissue matrix assisted laser desorption/ionization Fourier transform mass spectrometry, in combination with sustained off-resonance irradiation collision-induced dissociation, we found that at least one additional TRP is present in Cancer irroratus, Cancer borealis, Cancer magister, and Cancer productus. The novel TRP isoform, TPSGFLGMRamide, was present not only in the midgut, but also in the Stomatogastric Nervous System (STNS). In addition, we identified an unprocessed TRP precursor APSGFLGMRG, which was detected in midgut tissues only. TRP immunohistochemistry, in combination with preadsorption studies, suggests that APSGFLGMRamide and TPSGFLGMRamide are co-localized in the Stomatogastric ganglion (STG), which is contained within the STNS. Exogenous application of TPSGFLGMRamide to the STG elicited a pyloric motor pattern that was identical to that elicited by APSGFLGMRamide, whereas APSGFLGMRG did not alter the pyloric motor pattern.
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identification physiological actions and distribution of vyrkppfngsifamide val1 sifamide in the Stomatogastric Nervous System of the american lobster homarus americanus
The Journal of Comparative Neurology, 2006Co-Authors: Andrew E Christie, Elizabeth A. Stemmler, Braulio Peguero, Daniel I Messinger, Heather L Provencher, Pieter Scheerlinck, Yunwei A Hsu, Maureen E Guiney, Horacio O De La Iglesia, Patsy S. DickinsonAbstract:In this study, the peptide VYRKPPFNGSIFamide (Val1-SIFamide) was identified in the Stomatogastric Nervous System (STNS) of the American lobster, Homarus americanus, using matrix-assisted laser desorption/ionization-Fourier transform mass spectrometry (MALDI-FTMS). When bath-applied to the Stomatogastric ganglion (STG), synthetic Val1-SIFamide activated the pyloric motor pattern, increasing both burst amplitude and duration in the pyloric dilator (PD) neurons. To determine the distribution of this novel SIFamide isoform within the lobster STNS and neuroendocrine organs, a rabbit polyclonal antibody was generated against synthetic Val1-SIFamide. Whole-mount immunolabeling with this antibody showed that this peptide is widely distributed within the STNS, including extensive neuropil staining in the STG and commissural ganglia (CoGs) as well as immunopositive somata in the CoGs and the oesophageal ganglion. Labeling was also occasionally seen in the pericardial organ (PO), but not in the sinus gland. When present in the PO, labeling was restricted to fibers-of-passage and was never seen in release terminals. Adsorption of the antibody by either Val1-SIFamide or Gly1-SIFamide abolished all Val1-SIFamide staining within the STNS, including the STG neuropil, whereas adsorption by other lobster neuropeptides had no effect on immunolabeling. These data strongly suggest that the staining we report is a true reflection of the distribution of this peptide in the STNS. Collectively, our mass spectrometric, physiological, and anatomical data are consistent with Val1-SIFamide serving as a locally released neuromodulator in the lobster STG. Thus, our study provides the first direct demonstration of function for an SIFamide isoform in any species. J. Comp. Neurol. 496:406–421, 2006. © 2006 Wiley-Liss, Inc.
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the anterior cardiac plexus an intrinsic neurosecretory site within the Stomatogastric Nervous System of the crab cancer productus
The Journal of Experimental Biology, 2004Co-Authors: Andrew E Christie, Shaun D Cain, John M Edwards, Todd A Clason, Elena Cherny, Minhui Lin, Amitoz S Manhas, Kirsten L Sellereit, Nicholas G Cowan, Kellen A NoldAbstract:SUMMARY The Stomatogastric Nervous System (STNS) of decapod crustaceans is modulated by both locally released and circulating substances. In some species, including chelate lobsters and freshwater crayfish, the release zones for hormones are located both intrinsically to and at some distance from the STNS. In other crustaceans, including Brachyuran crabs, the existence of extrinsic sites is well documented. Little, however, is known about the presence of intrinsic neuroendocrine structures in these animals. Putative intrinsic sites have been identified within the STNS of several crab species, though ultrastructural confirmation that these structures are in fact neuroendocrine in nature remains lacking. Using a combination of anatomical techniques, we demonstrate the existence of a pair of neurosecretory sites within the STNS of the crab Cancer productus . These structures, which we have named the anterior cardiac plexi (ACPs), are located on the anterior cardiac nerves ( acn s), which overlie the cardiac sac region of the foregut. Each ACP starts several hundred μm from the origin of the acn and extends distally for up to several mm. Transmission electron microscopy done on these structures shows that nerve terminals are present in the peripheral portion of each acn , just below a well defined epineurium. These terminals contain dense-core and, occasionally, electron-lucent vesicles. In many terminals, morphological correlates of hormone secretion are evident. Immunocytochemistry shows that the ACPs are immunopositive for FLRFamide-related peptide. All FLRFamide labeling in the ACPs originates from four axons, which descend to these sites through the superior oesophageal and Stomatogastric nerves. Moreover, these FLRFamide-immunopositive axons are the sole source of innervation to the ACPs. Collectively, our results suggest that the STNS of C. productus is not only a potential target site for circulating hormones, but also serves as a neuroendocrine release center itself.
Petra Skiebe - One of the best experts on this subject based on the ideXlab platform.
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Neuropeptides in the crayfish Stomatogastric Nervous System
2015Co-Authors: Petra SkiebeAbstract:ABSTRACT Neuropeptides are peptides with profound effects on the Nervous System. The function of neuropeptides can be studied in detail in the Stomatogastric Nervous System (STNS). Neuropeptides are ubiquitously distributed in the STNS and it contains well-studied neural circuits that are strongly modulated by neuropeptides. The STNS controls the movements of the foregut in crustaceans and has been studied intensively in a variety of decapod crustaceans including crayfish. This article reviews our knowledge of neuropeptides in the crayfish STNS. Within crayfish, peptides reach the circuits of the STNS as neurohormones released by neurohaemal organs or by putative neurohemal zones located within the STNS. As transmitters, neuropeptides are present in identi-fied motoneurons, interneurons, and sensory neurons (mainly shown by immunocytochemistry), indicating a multiple role of peptides in the plasticity of neural networks. Neuropeptides are not only present in varicosities within the neuropil of ganglia, but also in varicosities on muscles and within small neuropil patches along nerves. This suggests that the muscles of the stomach are under a more direct modulatory control than previously thought, and that information processing can also occur within nerves. In addition to anatomical studies, biochemical and electrophysiolog-ical methods were used. For example, MALDI-TOF MS (matrix-assisted laser desorption ionizatio
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Neuropeptides in the crayfish Stomatogastric Nervous System.
Microscopy research and technique, 2003Co-Authors: Petra SkiebeAbstract:Neuropeptides are peptides with profound effects on the Nervous System. The function of neuropeptides can be studied in detail in the Stomatogastric Nervous System (STNS). Neuropeptides are ubiquitously distributed in the STNS and it contains well-studied neural circuits that are strongly modulated by neuropeptides. The STNS controls the movements of the foregut in crustaceans and has been studied intensively in a variety of decapod crustaceans including crayfish. This article reviews our knowledge of neuropeptides in the crayfish STNS. Within crayfish, peptides reach the circuits of the STNS as neurohormones released by neurohaemal organs or by putative neurohemal zones located within the STNS. As transmitters, neuropeptides are present in identified motoneurons, interneurons, and sensory neurons (mainly shown by immunocytochemistry), indicating a multiple role of peptides in the plasticity of neural networks. Neuropeptides are not only present in varicosities within the neuropil of ganglia, but also in varicosities on muscles and within small neuropil patches along nerves. This suggests that the muscles of the stomach are under a more direct modulatory control than previously thought, and that information processing can also occur within nerves. In addition to anatomical studies, biochemical and electrophysiological methods were used. For example, MALDI-TOF MS (matrix-assisted laser desorption ionization time of flight mass spectrometry) revealed the presence of four different peptides of the orcokinin family within a single neuron, and electrophysiological experiments demonstrated that the networks of the STNS are not only under excitatory but also inhibitory peptidergic influence. Comparing the similarities and differences between the STNS of crayfish and that of other decapod crustaceans has already contributed to our knowledge about peptides and will further help to unravel peptide function in the plasticity of neural circuits. For example, the identified neurons in the STNS can be used to study co-transmission because neuropeptides are co-localized with classical transmitters, biogenic amines, or other peptides in these neurons. Microsc. Res. Tech. 60:302–312, 2003. © 2003 Wiley-Liss, Inc.
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Immunocytochemical and molecular data guide peptide identification by mass spectrometry: orcokinin and orcomyotropin-related peptides in the Stomatogastric Nervous System of several crustacean species.
Cellular and molecular biology (Noisy-le-Grand France), 2003Co-Authors: Petra Skiebe, M. Dreger, J. Boerner, M. Meseke, Wolfram WeckwerthAbstract:In order to identify new orcokinin and orcomyotropin-related peptides in crustaceans, molecular and immunocytochemical data were combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In the crayfish Procambarus clarkii, four orcokinins and an orcomyotropin-related peptide are present on the precursor (42). Because these peptides are highly conserved, we assumed that other species have an identical number of peptides. To identify the peptides, immunocytochemistry was used to localize the regions of the Stomatogastric Nervous System in which orcokinins are predominantly present. One of the regions predominantly containing orcokinins was a previously undescribed olive-shaped neuropil region within the commissural ganglia of the lobsters Homarus americamis and Homarus gammarus. MALDI-TOF MS on these regions identified peptide masses that always occur together with the known orcokinins. Seven peptide ions occurred together in the peptide mass spectra of the lobsters. Mass spectrometric fragmentation by MALDI-MS post-source decay (PSD) and electrospray ionization quadrupole time-of-flight mass spectrometry (ESI Q-TOF MS) collision-induced dissociation (CID) were used in the identification of six of these masses, either as orcokinins or as orcomyotropin-related peptides and revealed three hitherto unknown peptide variants, two of which are [His 1 3 ]-orcokinin ([M+H] + = 1540.8 Da) and an orcomyotropin-related peptide FDAFTTGFGHN ([M+H] + = 1213.5 Da). The mass of the third previously unknown orcokinin variant corresponded to that of an identified orcokinin, but PSD fragmentation did not support the suggested amino acid sequence. CID analysis allowed partial de novo sequencing of this peptide. In the crab Cancer pagurus, five orcokinins and an orcomyotropin-related peptide were unambigously identified, including the previously unknown peptide variant [Ser 9 -Val 1 3 ]-orcokinin ([M + H] + = 1532.8 Da).
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Putative neurohemal release zones in the Stomatogastric Nervous System of decapod crustaceans.
The Journal of comparative neurology, 2002Co-Authors: Petra Skiebe, Tina WollenschlägerAbstract:The Stomatogastric Nervous System (STNS) of decapod crustaceans has long been used to study the modulation of small neural circuits. Profiles in the sheath of the nerves and ganglia of the STNS, which contain only dense-core vesicles, have been described in electron microscopical studies (Friend [1976] Cell Tissue Res. 175:369–380; Kilman and Marder [1997] Soc Neurosci Abstr. 23:477; Skiebe and Ganeshina [2000] J Comp Neurol 420:373–397). These profiles resemble those found in neurohemal organs and suggest the presence of neurohemal release zones in the STNS. To map these putative neurohemal release zones, a combination of two antibodies was used in the present study. A synapsin antibody recognizing vesicle proteins of clear vesicles was combined with a synaptotagmin antibody recognizing vesicle proteins of clear and dense-core vesicles. Exclusive synaptotagmin-like staining, therefore, indicated the regions with only dense-core vesicles. Such a staining was found in a mesh in the perineural sheath of nerves in the STNS of all three species investigated. In the crayfish Cherax destructor and the lobster Homarus americanus, the stained mesh was located in the sheath of nerves connecting all four ganglia of the STNS, whereas in the crab Cancer pagurus it was found on different nerves, which are more directly exposed to the hemolymph in this species. Exclusive synaptotagmin-like staining was also found in a putative neurohemal release zone in the sheath of the circumoesophageal connectives and the postoesophageal commissure in C. destructor. These data suggest that an important source of modulation of the networks and the muscles of the stomach is a compartmentalized release of neurohormones from zones in the STNS. J. Comp. Neurol. 453:280–291, 2002. © 2002 Wiley-Liss, Inc.
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Identification of orcokinins in single neurons in the Stomatogastric Nervous System of the crayfish, Cherax destructor
The Journal of comparative neurology, 2002Co-Authors: Petra Skiebe, Mathias Dreger, Maurice Meseke, Jan Felix Evers, Ferdinand HuchoAbstract:The orcokinins are a highly conserved family of crustacean peptides that enhance hindgut contractions in the crayfish Orconectes limosus (Stangier et al. [1992] Peptides 13:859–864). By combining immunocytochemical and mass spectrometrical analysis of the Stomatogastric Nervous System (STNS) in the crayfish Cherax destructor, we show that multiple orcokinins are synthesized in single neurons. Immunocytochemistry demonstrated orcokinin-like immunoreactivity in all four ganglia of the STNS and in the pericardial organs, a major neurohaemal organ. Identified neurons in the STNS were stained, including a pair of modulatory interneurons (inferior ventricular nerve neuron, IVN), a neuron with its cell body in the Stomatogastric ganglion that innervates cardiac muscle c6 via the anterior median nerves (AM-c6), and a sensory neuron (anterior gastric receptor neuron). Five orcokinin-related peptides were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) post source decay fragmentation in samples of either the Stomatogastric ganglion or the pericardial organs. Four of these peptides are identical to peptides derived from the cloned Procambarus clarkii precursor (Yasuda-Kamatani and Yasuda [2000] Gen. Comp. Endocrinol. 118:161–172), including the original [Asn13]-orcokinin (NFDEIDRSGFGFN, [M+H]+ = 1,517.7 Da), [Val13]-orcokinin ([M+H]+ = 1,502.7 Da), [Thr8-His13]-orcokinin ([M+H]+ = 1,554.8 Da), and FDAFTTGFGHS ([M+H]+ = 1,186.5 Da). The fifth peptide is a hitherto unknown orcokinin variant: [Ala8-Ala13]-orcokinin ([M+H]+ = 1,458.7 Da). The masses of all five peptides were also detected in the inferior ventricular nerve of C. destructor, which contains the cell bodies and axons of the IVNs as well as the axons of two other orcokinin-like immunoreactive neurons. In the oesophageal nerve, in which all the orcokinin-like immunoreactivity derives from the IVNs, at least two of the orcokinins were detected, indicating that multiple orcokinins are synthesized in these neurons. Similarly, all four orcokinin masses were detected in the anterior median nerves, in which all the orcokinin-like immunoreactivity derives from the AM-c6 neuron. This study therefore lays the groundwork to investigate the function of the orcokinin peptide family using single identified neurons in a well-studied System. J. Comp. Neurol. 444:245–259, 2002. © 2002 Wiley-Liss, Inc.
Michael P Nusbaum - One of the best experts on this subject based on the ideXlab platform.
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actions of a histaminergic peptidergic projection neuron on rhythmic motor patterns in the Stomatogastric Nervous System of the crab cancer borealis
The Journal of Comparative Neurology, 2004Co-Authors: Eve Marder, Andrew E Christie, Wolfgang Stein, John E Quinlan, Mark P Beenhakker, Michael P NusbaumAbstract:Histamine is a neurotransmitter with actions throughout the Nervous System of vertebrates and invertebrates. Nevertheless, the actions of only a few identified histaminecontaining neurons have been characterized. Here, we present the actions of a histaminergic projection neuron on the rhythmically active pyloric and gastric mill circuits within the Stomatogastric ganglion (STG) of the crab Cancer borealis. An antiserum generated against histamine labeled profiles throughout the C. borealis Stomatogastric Nervous System. Labeling occurred in several somata and neuropil within the paired commissural ganglia as well as in neuropil within the STG and at the junction of the superior oesophageal and Stomatogastric nerves. The source of all histamine-like immunolabeling in the STG neuropil was one pair of neuronal somata, the previously identified inferior ventricular (IV) neurons, located in the supraoesophageal ganglion. These neurons also exhibited FLRFamide-like immunoreactivity. Activation of the IV neurons in the crab inhibited some pyloric and gastric mill neurons and, with inputs from the commissural ganglia eliminated, terminated both rhythms. Focal application of histamine had comparable effects. The actions of both applied histamine and IV neuron stimulation were blocked, reversibly, by the histamine type-2 receptor antagonist cimetidine. With the commissural ganglia connected to the STG, IV neuron stimulation elicited a longer-latency activation of commissural projection neurons which in turn modified the pyloric rhythm and activated the gastric mill rhythm. These results support the hypothesis that the histaminergic/peptidergic IV neurons are projection neurons with direct and indirect actions on the STG circuits of the crab C. borealis. J. Comp. Neurol. 469:153–169, 2004. © 2003 Wiley-Liss, Inc.
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actions of a histaminergic peptidergic projection neuron on rhythmic motor patterns in the Stomatogastric Nervous System of the crab cancer borealis
The Journal of Comparative Neurology, 2004Co-Authors: Eve Marder, Andrew E Christie, Wolfgang Stein, John E Quinlan, Mark P Beenhakker, Michael P NusbaumAbstract:Histamine is a neurotransmitter with actions throughout the Nervous System of vertebrates and invertebrates. Nevertheless, the actions of only a few identified histamine-containing neurons have been characterized. Here, we present the actions of a histaminergic projection neuron on the rhythmically active pyloric and gastric mill circuits within the Stomatogastric ganglion (STG) of the crab Cancer borealis. An antiserum generated against histamine labeled profiles throughout the C. borealis Stomatogastric Nervous System. Labeling occurred in several somata and neuropil within the paired commissural ganglia as well as in neuropil within the STG and at the junction of the superior oesophageal and Stomatogastric nerves. The source of all histamine-like immunolabeling in the STG neuropil was one pair of neuronal somata, the previously identified inferior ventricular (IV) neurons, located in the supraoesophageal ganglion. These neurons also exhibited FLRFamide-like immunoreactivity. Activation of the IV neurons in the crab inhibited some pyloric and gastric mill neurons and, with inputs from the commissural ganglia eliminated, terminated both rhythms. Focal application of histamine had comparable effects. The actions of both applied histamine and IV neuron stimulation were blocked, reversibly, by the histamine type-2 receptor antagonist cimetidine. With the commissural ganglia connected to the STG, IV neuron stimulation elicited a longer-latency activation of commissural projection neurons which in turn modified the pyloric rhythm and activated the gastric mill rhythm. These results support the hypothesis that the histaminergic/peptidergic IV neurons are projection neurons with direct and indirect actions on the STG circuits of the crab C. borealis.
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Actions of a histaminergic/peptidergic projection neuron on rhythmic motor patterns in the Stomatogastric Nervous System of the crab Cancer borealis
The Journal of comparative neurology, 2004Co-Authors: Andrew E Christie, Eve Marder, Wolfgang Stein, John E Quinlan, Mark P Beenhakker, Michael P NusbaumAbstract:Histamine is a neurotransmitter with actions throughout the Nervous System of vertebrates and invertebrates. Nevertheless, the actions of only a few identified histamine-containing neurons have been characterized. Here, we present the actions of a histaminergic projection neuron on the rhythmically active pyloric and gastric mill circuits within the Stomatogastric ganglion (STG) of the crab Cancer borealis. An antiserum generated against histamine labeled profiles throughout the C. borealis Stomatogastric Nervous System. Labeling occurred in several somata and neuropil within the paired commissural ganglia as well as in neuropil within the STG and at the junction of the superior oesophageal and Stomatogastric nerves. The source of all histamine-like immunolabeling in the STG neuropil was one pair of neuronal somata, the previously identified inferior ventricular (IV) neurons, located in the supraoesophageal ganglion. These neurons also exhibited FLRFamide-like immunoreactivity. Activation of the IV neurons in the crab inhibited some pyloric and gastric mill neurons and, with inputs from the commissural ganglia eliminated, terminated both rhythms. Focal application of histamine had comparable effects. The actions of both applied histamine and IV neuron stimulation were blocked, reversibly, by the histamine type-2 receptor antagonist cimetidine. With the commissural ganglia connected to the STG, IV neuron stimulation elicited a longer-latency activation of commissural projection neurons which in turn modified the pyloric rhythm and activated the gastric mill rhythm. These results support the hypothesis that the histaminergic/peptidergic IV neurons are projection neurons with direct and indirect actions on the STG circuits of the crab C. borealis.
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Convergence and Divergence of Cotransmitter Systems in the Crab Stomatogastric Nervous System
The Crustacean Nervous System, 2002Co-Authors: Eve Marder, Andrew E Christie, Dawn M Blitz, Andrew M. Swensen, Michael P NusbaumAbstract:Many neurons contain multiple cotransmitters, including neuropeptides. In the Stomatogastric Nervous System a number of different neuropeptides are found colocalized with small molecule neurotransmitters. Three proctolin-containing projection neurons contain different cotransmitters, and modulate the Stomatogastric ganglion motor patterns differently. A number of neuropeptides, including proctolin, found in inputs to the Stomatogastric ganglion, converge onto the same membrane current. This includes colocalized peptides. Studying the peptidergic modulation of the Stomatogastric ganglion provides a unique opportunity to uncover general principles of organization of peptidergic control Systems.
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Pyloric motor pattern modification by a newly identified projection neuron in the crab Stomatogastric Nervous System.
Journal of neurophysiology, 1996Co-Authors: Brian J. Norris, Melissa J. Coleman, Michael P NusbaumAbstract:1. We have used multiple, simultaneous intra- and extracellular recordings as well as Lucifer yellow dye-fills to identify modulatory commissural neuron 5 (MCN5) and characterize its effects in the Stomatogastric Nervous System (STNS) of the crab, Cancer borealis. MCN5 has a soma and neuropilar arborization in the commissural ganglion (CoG; Figs. 1 and 2), and it projects through the inferior esophageal nerve (ion) and Stomatogastric nerve (stn) to the Stomatogastric ganglion (STG; Figs. 1-3). 2. Within the CoGs, MCN5 receives esophageal rhythm-timed excitation and pyloric rhythm-timed inhibition (Fig. 4). Additionally, during the lateral teeth protractor phase of the gastric mill rhythm, the pyloric-timed inhibition of MCN5 is reduced or eliminated. 3. Intracellular stimulation of MCN5 excites the pyloric pacemaker ensemble, including the anterior burster (AB), pyloric dilator (PD), and lateral posterior gastric (LPG) neurons. This produces a faster pyloric rhythm. MCN5 stimulation also inhibits all nonpacemaker pyloric neurons, reducing or eliminating their activity (Figs. 5 and 6A; Tables 1 and 2). After MCN5 stimulation, bursting is enhanced for several cycles in some pyloric neurons when compared with their prestimulus activity (Figs. 5 and 6A; Tables 1 and 2). 4. MCN5 evokes distinct responses from each pyloric pacemaker neuron (Figs. 6-8). The AB and LPG neurons respond with increased activity. The AB response includes the presence of large amplitude excitatory postsynaptic potentials (EPSPs) that contribute to a depolarization of the trough of its rhythmic oscillations (Fig. 6). LPG responds by exhibiting increased activity that prolongs the duration of its burst beyond that of AB and PD (Fig. 7). In contrast, MCN5 stimulation initially produces decreased PD neuron activity, followed by a slight enhancement of each PD burst (Figs. 7 and 8). PD activity is further enhanced after MCN5 stimulation (Figs. 7 and 8). 5. MCN5-elicited action potentials evoke discrete, constant latency inhibitory postsynaptic potentials (IPSPs) in all nonpacemaker pyloric neurons, including the inferior cardiac (IC), lateral pyloric (LP), pyloric (PY), and ventricular dilator (VD) neurons (Fig. 9). MCN5 activity also inhibits these neurons indirectly, via its excitation of the pacemaker neurons. The pyloric pacemaker neurons synaptically inhibit all four nonpacemaker neurons. 6. The increased activity in the VD neuron, after MCN5 stimulation, is not mimicked by either direct hyperpolarization or by synaptically inhibiting VD via another pathway (Fig. 10). The poststimulation increase in IC neuron activity is stronger than that after hyperpolarizing current injection but is comparable with that resulting from stimulation of another inhibitory pathway (Fig. 10). The enhanced PY neuron activity is comparable with that resulting from either direct current injection or synaptic inhibition from another pathway (Fig. 10). 7. MCN5 activity increases the pyloric cycle frequency of both slow (< 1 Hz) and fast (1-2 Hz) rhythms (Fig. 11), and it significantly alters the phase relationships that define this motor pattern (Fig. 12). These phase relationships change again after MCN5 stimulation (Fig. 12). 8. MCN5 acts in concert with the pyloric pacemaker ensemble to elicit a pyloric rhythm that exhibits enhanced pacemaker neuron activity and reduced activity in all nonpacemaker neurons. Additionally, despite their electrical coupling, the three types of pacemaker neurons exhibit distinct responses to MCN5 stimulation. This partially uncouples their normally coactive bursts. The resulting motor pattern is distinct from all previously characterized pyloric rhythms.
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Effects of azadirachtin on the regulation of midgut peristalsis by the Stomatogastric Nervous System in Locusta migratoria
Phytoparasitica, 2000Co-Authors: Peter Trumm, August DornAbstract:A single injection of azadirachtin into nymphal and adult locusts results in a decrease of food intake but not in reduced food utilization. Feeding deterrency is correlated with a gradual inhibition of midgut peristalsis. Gut movement is under the control of the Stomatogastric Nervous System, especially the ingluvial ganglion, as demonstrated in anin vitro System. Serotonin is the most potent peristalsis-stimulating drugin vitro. Concurrent with the cessation of midgut peristalsis after azadirachtin injection, a depletion of the serotoninergic cell bodies in the frontal ganglion can be observed. Midgut preparations which show strongly inhibited contractions due to previous azadirachtin treatmentin vivo are minimally, or not at all, stimulatedin vitro by serotonin, depending on the amount of time that has elapsed since treatment. When midgut preparations of untreated locusts are challenged with azadirachtinin vitro, peristalsis is suppressed in a dose-dependent manner. Simultaneous application of azadirachtin and serotonin results in a slight stimulation of midgut peristalsis. We propose the hypothesis that azadirachtin interferes with the serotoninergic System of the Stomatogastric ganglia and thus inhibits midgut peristalsis. The molecular mechanism of the action of azadirachtin remains to be determined.
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Effects of azadirachtin on the regulation of midgut peristalsis by the Stomatogastric Nervous System inLocusta migratoria
Phytoparasitica, 2000Co-Authors: Peter Trumm, August DornAbstract:A single injection of azadirachtin into nymphal and adult locusts results in a decrease of food intake but not in reduced food utilization. Feeding deterrency is correlated with a gradual inhibition of midgut peristalsis. Gut movement is under the control of the Stomatogastric Nervous System, especially the ingluvial ganglion, as demonstrated in an in vitro System. Serotonin is the most potent peristalsis-stimulating drug in vitro. Concurrent with the cessation of midgut peristalsis after azadirachtin injection, a depletion of the serotoninergic cell bodies in the frontal ganglion can be observed. Midgut preparations which show strongly inhibited contractions due to previous azadirachtin treatment in vivo are minimally, or not at all, stimulated in vitro by serotonin, depending on the amount of time that has elapsed since treatment. When midgut preparations of untreated locusts are challenged with azadirachtin in vitro , peristalsis is suppressed in a dose-dependent manner. Simultaneous application of azadirachtin and serotonin results in a slight stimulation of midgut peristalsis. We propose the hypothesis that azadirachtin interferes with the serotoninergic System of the Stomatogastric ganglia and thus inhibits midgut peristalsis. The molecular mechanism of the action of azadirachtin remains to be determined.
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immunohistochemical demonstration in the Stomatogastric Nervous System and effects of putative neurotransmitters on the motility of the isolated midgut of the stick insect carausius morosus
Journal of Insect Physiology, 1992Co-Authors: Dieter Luffy, August DornAbstract:The effects of various pharmacological agents (serotonin, GABA, octopamine, dopamine, noradrenaline and acetylcholine) on the motility of the isolated midgut were tested in Carausius morosus. It proved to be crucial whether the midgut preparations included the ingluvial ganglion (“innervated” midgut) or not (“denervated” midgut). The isolated, “innervated” midgut exhibited spontaneous, rhythmic contractions and relaxations. The isolated, “denervated” midgut was quiescent. On the “denervated” midgut, low doses of serotonin induced a long-lasting, dose-dependent contraction. A similar effect was exerted by medium doses of octopamine and high doses of dopamine and acetylcholine. GABA and noradrenaline showed no reaction. The spontaneous rhythmic contractions of the “innervated” midgut were influenced by serotonin, octopamine and GABA. Serotonin increased both frequency and amplitude, octopamine only the frequency. GABA decreased the amplitude or suppressed the contractions completely depending on the dose. Serotonin applied at intermittant quiescent phases of the “innervated” midgut reinstated the typical spontaneous rhythmics. The presence of serotonin, GABA, dopamine and noradrenaline in the Stomatogastric Nervous System (including branches of the nervi ingluviales which innervate the midgut) was tested by immunohistochemistry. Positive reactions were obtained for serotonin and GABA whereas dopamine and noradrenaline were not demonstrable. The results are discussed with respect to the putative role of the tested pharmacological agents as neurotransmitter, neuromodulator or neurohormone. They are compared with findings in other insects and decapods.
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serotoninergic elements in the Stomatogastric Nervous System of the stick insect carausius morosus demonstrated by immunohistochemistry
Journal of Insect Physiology, 1991Co-Authors: Dieter Luffy, August DornAbstract:Abstract The organization of the Stomatogastric Nervous System of Carausius morosus has been studied, and serotoninergic elements have been visualized by immunohistochemistry. Of the three Stomatogastric ganglia, only the frontal ganglion includes serotoninergic perikarya (seven pairs). Serotoninergic nerve fibres are abundant in all parts of the Stomatogastric Nervous System. Analyses from serial sections suggest that axons from cerebral serotoninergic neurones reach the frontal ganglion via frontal connectives and may partly run through all Stomatogastric ganglia and connecting nerves and finally end at the outer longitudinal muscles of fore- and midgut. Some of the cerebral serotoninergic axons ramify strongly in the neuropil of all Stomatogastric ganglia. The axonal pathways of the serotoninergic perikarya of the frontal ganglion were difficult to trace. It seems that some run into the frontal connectives whereas probably most of them run caudally. In the ingluvial ganglion, serotoninergic axons form conspicuous “end swellings”.
