Sono descritti gli effetti di un trattamento traumatico sui livelli di morfina endogena in cellul... more Sono descritti gli effetti di un trattamento traumatico sui livelli di morfina endogena in cellule sia del sistema immunitario che di quello nervoso nel gasteropode Planorbariu
An antibody raised against CDCH (caudodorsal cell hormone) the egg-laying hormone of Lymnaes stag... more An antibody raised against CDCH (caudodorsal cell hormone) the egg-laying hormone of Lymnaes stagnalis (Lymnaeidae, Gasteropoda) has been used to identify neurosecretory cells and a neurohemal site in the cerebral ganglia of Venus verrucosa (veneridae, Bivalvia) Results show that, as in Lymnaea, a cortical layer including the part of ganglia close to intercerebral commissure itself, may constitute the site of storage and release of the neurosecretion in the hemolimph. In both sexes, CDCH-immunoreactive neurons have been labelled, suggesting their homology with the Caudo Dorsal Cells of Lymnaea
The neurite outgrowth of dissociated cells from the central ganglia of the molluscan Planorbarius... more The neurite outgrowth of dissociated cells from the central ganglia of the molluscan Planorbarius corneus (L.) was observed. The best conditions for the neurite outgrowth were found
Endoreplication has been repeatedly found in eukaryotes. In particular, endoreplicative or endodu... more Endoreplication has been repeatedly found in eukaryotes. In particular, endoreplicative or endoduplicative mechanisms have been reported in protists, plants, arthropods, molluscs, fishes and mammals. The same studies indicated that cells possessing endoreplicated genome are generally large-sized and highly metabolically active, suggesting that endoreplication could have a functional significance. Neurons are typically considered as fully differentiated, non-dividing cells containing normally a diploid DNA amount, and endoreplication has not been historically reported in neuronal cells. Despite this general rule, some papers questioned the validity of this finding and indicated that giant neurons in molluscs, supramedullary and hypothalamic magnocellular neurons in fishes and Purkinje cells in vertebrate (prevalently mammal) cerebellum present DNA contents greater than 2C. Quantitative microfluorometric evaluation of DNA content in nerve cells of the gastropod molluscs Planorbarius corneus, Aplysia californica and Lymnaea stagnalis indicated that neuronal DNA contents are scattered between 2C and 200.000C values. This increase in DNA content is given in account mostly to whole-genome duplications, whereas in P. corneus an endoreplication mainly of GC-rich sequences occurs. The second example of endoreplicated neurons was highlighted in the large clustered neurons, located at the boundary between the medulla oblongata and spinal cord, of the fishes Lophius piscatorius and Diodon holacanthus. The DNA content of these neurons, evaluated by microfluorimetric methods, results ranging from a minimum of 4C in the smaller to over 5000C in the larger neurons. Further experiments with AT and GC specific fluorochromes showed that the increase in DNA content is due to an amplification involving GC-rich DNAs in L. piscatorius, whereas a whole-genome endoduplication occurs in D. holacanthus. Subsequent quantitative evaluation revealed that also L. piscatorius hypothalamic magnocellular neurons, located in the preoptic and tuberal complexes, largely exceed 2C DNA content. The last example is represented by nuclei of vertebrate Purkinje cells isolated from cerebellum. These results have been debated for several years, since contrasting data are present in literature. Up till now, the dilemma remains unsolved, but it is not possible to exclude that a small percentage of Purkinje neurons contains hyperdiploid and tetraploid nuclei, might be due to an extra DNA synthesis. In order to go in depth in the understanding of this topic, we revised in the present review the available data about endoreplication in invertebrate and vertebrate giant neurons and considered the possible molecular mechanisms responsible for endoreplication. Furthermore, some possible functional significances of neuron endoploidy are discussed
In this paper we review the present information on the chemosensory spectrum of freshwater snails... more In this paper we review the present information on the chemosensory spectrum of freshwater snails with particular reference to our study on Planorbarius. By comparing our results with other data from literature, it is evident that different species have different chemosensory spectra as a function of their ecological adaptation
The outgrowth of new neurites from cultured neurons of Planorbarius corneus (Mollusca) is require... more The outgrowth of new neurites from cultured neurons of Planorbarius corneus (Mollusca) is required to have in the culture medium a neurotrophic factor released from a number of complete ganglionic rings. Preliminary results show that even partial ganglionic rings are satisfactory for the releasing of the neurotrophic factor. The best results were obtained with a medium incubated only with the cerebral ganglia
The communication among the nervous, endocrine and immune systems includes many signal molecule f... more The communication among the nervous, endocrine and immune systems includes many signal molecule families. We have found that endogenous morphine contents rose in ganglia and haemolynph of Mytilus after experimental trauma or induced stress. Other experimts reveal a morphine-like immunoreavictivity in ganglia and microglia of Mytilus and Planorbarius. The emerging data indicate that an endogenous morphinergic signaling system exists in invertebrates
The majority of neurons belonging to the central nervous system of the mollusc Planorbarius corne... more The majority of neurons belonging to the central nervous system of the mollusc Planorbarius corneus is capable of neurite regeneration in vitro only in presence of factors released from the periesophageal ganglionic ring. Even each individual ganglion produces unknown stimulating factors sufficient for a complete neurite regeneration. The percentage of neurons showing neurite regeneration is nearly the same independent of ganglionic type and it increases following a rise in the concentration of promoting factors. We identified by RIA an insulin -like molecule among the released substances. Adding antisera against molluscan insulin -like neuropeptides to the culture medium we obtained an almost complete inhibition of neurite regeneration when the factors are released by cerebral or pedal ganglia. No inhibition occurs if the neural factors are released by visceroparietal ganglia
Despite being characterized by some of the most threatened forest ecosystems of Mesoamerica, the ... more Despite being characterized by some of the most threatened forest ecosystems of Mesoamerica, the Nicoya Peninsula is among the least known regions of neotropical Costa Rica in terms of its birdlife. Within this region, in the framework of an ongoing international cooperation program between Italy and Costa Rica, we had the opportunity to investigate the Karen Mogensen Reserve, a protected area distinguished by the presence of a variety of habitats, including tropical dry forest and moist forest. Species richness in the Reserve was relatively high compared with similar areas in northwestern Costa Rica. A series of surveys carried out over a 20-year period documented an avian community consisting of 207 species, of which 115 were breeding in the zone and another 14 were potentially breeding. We recorded five IUCN globally Vulnerable or Near-Threatened species, along with six species reported for the first time from the Nicoya Peninsula, each representing range extension of more than 1...
Medical science monitor : international medical journal of experimental and clinical research, 2004
Morphine is the most used compound among narcotic analgesics. Apart from its presence in the popp... more Morphine is the most used compound among narcotic analgesics. Apart from its presence in the poppy plant, morphine has been shown to be endogenously present in different tissues of mammals and lower animals. The presence of endogenous morphine and codeine was investigated by Gas Chromatography/ Mass Spectrometry (GC/MS) in the brain of non human primate. The release of endogenous morphine from monkey brain slices was studied in vitro in the presence of high potassium concentrations with and without calcium in the medium. Endogenous morphine, and its direct precursor codeine, was for the first time detected by GC/MS in the brain of non human primate. High potassium concentrations depolarized neurons releasing endogenous morphine twofold above basal line levels in a calcium dependent mechanism. This finding confirms the presence of the endogenous alkaloid throughout the phylogenesis of the nerve system of mammals and lower animals and indicates that endogenous morphine might function ...
Medical science monitor : international medical journal of experimental and clinical research, 2005
Endogenous morphine and proopiomelanocortin-derived peptide-like molecules were identified in mol... more Endogenous morphine and proopiomelanocortin-derived peptide-like molecules were identified in molluscan tissues, including the nervous system, supporting their ancient phylogeny. Their presence and function in "simple" animals, demonstrates their involvement in mechanisms underlying the stress response, preceding the mammalian neuroendocrine axis. Immunocytochemical analysis was used to study the localization of morphine- and adrenocorticotropic hormone (ACTH)-like material in the nervous system of Planorbarius corneus, Mytilus galloprovincialis, Lymnaea stagnalis and Viviparus ater. Acute stress experiments were performed on P. corneus and, by radioimmune assay, we quantified the expression of an ACTH-like peptide in control and stressed animals. We demonstrate that in mollusks the presence of a morphine-like compound is differentially distributed in neuronal structures containing an ACTH-like molecule. In P. corneus, the two immunoreactivities appear to be colocalized in...
Cultures of isolated neuronal populations from the central ganglia of the gastropod mollusc Plano... more Cultures of isolated neuronal populations from the central ganglia of the gastropod mollusc Planorbarius corneus were used for testing the effects of inorganic lead. The examined parameters were cell survival, neurite outgrowth and cytoskeletal morphology. In large heterogeneous neuronal populations as obtained from a whole cerebral or pedal ganglion, the different sensitivity to lead is reflected mainly on the cell survival. The neurons belonging to the homogeneous E cluster population are more sensitive; in fact a higher percentage of them do not survive in the presence of lead. Moreover, in this neuronal cell type the neurite outgrowth is dramatically affected by lead only when the neurons are cultured on conditioned substrate. Possibly, membrane mechanisms activated for the neurite outgrowth represent a target for inorganic lead. The few neurites sprouted in presence of lead do not evidence changes in the cytoskeletal components.
Insulin receptor-like immunoreactivity (IR) was investigated in the central ganglia of different ... more Insulin receptor-like immunoreactivity (IR) was investigated in the central ganglia of different gastropod molluscs using a monoclonal antiserum raised against an epitope of the human placental insulin receptor. A well detectable and clear location of immunoreactive material was mainly found in the CNS of the freshwater snails Planorbarius corneus and Lymnaea stagnalis. This evidence correlates quite suggestively with the occurrence in these snails of a molluscan insulin peptide (MIP) previously shown. The widespread and discrete distribution of IR over a variety of physiologically distinct regions of P. corneus and L. stagnalis ganglia argues that these "receptors" may modulate multiple functions within the CNS.
E' stao effettuato uno screening immunocitochimico che ha dimostratyo la presenza nel sistema... more E' stao effettuato uno screening immunocitochimico che ha dimostratyo la presenza nel sistema nervoso gangliare del bivalve Venus di alcuni neurotrasmettitori e neuropeptidi, come i peptidi "CDC" implicati nel comporatamento riproduttivo dei gasteropodi e di altri bivalvi
1. Evidence supporting the presence in the invertebrate nervous system of a class of glial cells ... more 1. Evidence supporting the presence in the invertebrate nervous system of a class of glial cells resembling vertebrate microglia was obtained in the freshwater snail Planorbarius corneus. These cells are easily identified by their immunopositivity to anti-pro-opiomelanocortin (POMC)-derived peptide antibodies. 2. Invertebrate microglia, as in vertebrates, exhibit macrophage-like activity in vivo and in cell cultures. These cells respond to the trauma of ganglionic excision and their organotypic culture by leaving their location around neurons and moving to the lesion site from which they migrate in the culture dish. 3. In vitro, these microglia undergo conformational changes and show phagocytic properties in the presence of bacteria or lipopolysaccharide. The activated cells also express tumor necrosis factor-alpha-like material and an increase in nitric oxide synthase, as shown by immunocytochemistry. 4. The inhibitory effect of morphine on the mobility and phagocytic activity of invertebrate microglia provide additional functional evidence for a possible role of opiate-like compounds in downregulating immunoregulatory processes, as also observed in the circulating immunocytes.
Sono descritti gli effetti di un trattamento traumatico sui livelli di morfina endogena in cellul... more Sono descritti gli effetti di un trattamento traumatico sui livelli di morfina endogena in cellule sia del sistema immunitario che di quello nervoso nel gasteropode Planorbariu
An antibody raised against CDCH (caudodorsal cell hormone) the egg-laying hormone of Lymnaes stag... more An antibody raised against CDCH (caudodorsal cell hormone) the egg-laying hormone of Lymnaes stagnalis (Lymnaeidae, Gasteropoda) has been used to identify neurosecretory cells and a neurohemal site in the cerebral ganglia of Venus verrucosa (veneridae, Bivalvia) Results show that, as in Lymnaea, a cortical layer including the part of ganglia close to intercerebral commissure itself, may constitute the site of storage and release of the neurosecretion in the hemolimph. In both sexes, CDCH-immunoreactive neurons have been labelled, suggesting their homology with the Caudo Dorsal Cells of Lymnaea
The neurite outgrowth of dissociated cells from the central ganglia of the molluscan Planorbarius... more The neurite outgrowth of dissociated cells from the central ganglia of the molluscan Planorbarius corneus (L.) was observed. The best conditions for the neurite outgrowth were found
Endoreplication has been repeatedly found in eukaryotes. In particular, endoreplicative or endodu... more Endoreplication has been repeatedly found in eukaryotes. In particular, endoreplicative or endoduplicative mechanisms have been reported in protists, plants, arthropods, molluscs, fishes and mammals. The same studies indicated that cells possessing endoreplicated genome are generally large-sized and highly metabolically active, suggesting that endoreplication could have a functional significance. Neurons are typically considered as fully differentiated, non-dividing cells containing normally a diploid DNA amount, and endoreplication has not been historically reported in neuronal cells. Despite this general rule, some papers questioned the validity of this finding and indicated that giant neurons in molluscs, supramedullary and hypothalamic magnocellular neurons in fishes and Purkinje cells in vertebrate (prevalently mammal) cerebellum present DNA contents greater than 2C. Quantitative microfluorometric evaluation of DNA content in nerve cells of the gastropod molluscs Planorbarius corneus, Aplysia californica and Lymnaea stagnalis indicated that neuronal DNA contents are scattered between 2C and 200.000C values. This increase in DNA content is given in account mostly to whole-genome duplications, whereas in P. corneus an endoreplication mainly of GC-rich sequences occurs. The second example of endoreplicated neurons was highlighted in the large clustered neurons, located at the boundary between the medulla oblongata and spinal cord, of the fishes Lophius piscatorius and Diodon holacanthus. The DNA content of these neurons, evaluated by microfluorimetric methods, results ranging from a minimum of 4C in the smaller to over 5000C in the larger neurons. Further experiments with AT and GC specific fluorochromes showed that the increase in DNA content is due to an amplification involving GC-rich DNAs in L. piscatorius, whereas a whole-genome endoduplication occurs in D. holacanthus. Subsequent quantitative evaluation revealed that also L. piscatorius hypothalamic magnocellular neurons, located in the preoptic and tuberal complexes, largely exceed 2C DNA content. The last example is represented by nuclei of vertebrate Purkinje cells isolated from cerebellum. These results have been debated for several years, since contrasting data are present in literature. Up till now, the dilemma remains unsolved, but it is not possible to exclude that a small percentage of Purkinje neurons contains hyperdiploid and tetraploid nuclei, might be due to an extra DNA synthesis. In order to go in depth in the understanding of this topic, we revised in the present review the available data about endoreplication in invertebrate and vertebrate giant neurons and considered the possible molecular mechanisms responsible for endoreplication. Furthermore, some possible functional significances of neuron endoploidy are discussed
In this paper we review the present information on the chemosensory spectrum of freshwater snails... more In this paper we review the present information on the chemosensory spectrum of freshwater snails with particular reference to our study on Planorbarius. By comparing our results with other data from literature, it is evident that different species have different chemosensory spectra as a function of their ecological adaptation
The outgrowth of new neurites from cultured neurons of Planorbarius corneus (Mollusca) is require... more The outgrowth of new neurites from cultured neurons of Planorbarius corneus (Mollusca) is required to have in the culture medium a neurotrophic factor released from a number of complete ganglionic rings. Preliminary results show that even partial ganglionic rings are satisfactory for the releasing of the neurotrophic factor. The best results were obtained with a medium incubated only with the cerebral ganglia
The communication among the nervous, endocrine and immune systems includes many signal molecule f... more The communication among the nervous, endocrine and immune systems includes many signal molecule families. We have found that endogenous morphine contents rose in ganglia and haemolynph of Mytilus after experimental trauma or induced stress. Other experimts reveal a morphine-like immunoreavictivity in ganglia and microglia of Mytilus and Planorbarius. The emerging data indicate that an endogenous morphinergic signaling system exists in invertebrates
The majority of neurons belonging to the central nervous system of the mollusc Planorbarius corne... more The majority of neurons belonging to the central nervous system of the mollusc Planorbarius corneus is capable of neurite regeneration in vitro only in presence of factors released from the periesophageal ganglionic ring. Even each individual ganglion produces unknown stimulating factors sufficient for a complete neurite regeneration. The percentage of neurons showing neurite regeneration is nearly the same independent of ganglionic type and it increases following a rise in the concentration of promoting factors. We identified by RIA an insulin -like molecule among the released substances. Adding antisera against molluscan insulin -like neuropeptides to the culture medium we obtained an almost complete inhibition of neurite regeneration when the factors are released by cerebral or pedal ganglia. No inhibition occurs if the neural factors are released by visceroparietal ganglia
Despite being characterized by some of the most threatened forest ecosystems of Mesoamerica, the ... more Despite being characterized by some of the most threatened forest ecosystems of Mesoamerica, the Nicoya Peninsula is among the least known regions of neotropical Costa Rica in terms of its birdlife. Within this region, in the framework of an ongoing international cooperation program between Italy and Costa Rica, we had the opportunity to investigate the Karen Mogensen Reserve, a protected area distinguished by the presence of a variety of habitats, including tropical dry forest and moist forest. Species richness in the Reserve was relatively high compared with similar areas in northwestern Costa Rica. A series of surveys carried out over a 20-year period documented an avian community consisting of 207 species, of which 115 were breeding in the zone and another 14 were potentially breeding. We recorded five IUCN globally Vulnerable or Near-Threatened species, along with six species reported for the first time from the Nicoya Peninsula, each representing range extension of more than 1...
Medical science monitor : international medical journal of experimental and clinical research, 2004
Morphine is the most used compound among narcotic analgesics. Apart from its presence in the popp... more Morphine is the most used compound among narcotic analgesics. Apart from its presence in the poppy plant, morphine has been shown to be endogenously present in different tissues of mammals and lower animals. The presence of endogenous morphine and codeine was investigated by Gas Chromatography/ Mass Spectrometry (GC/MS) in the brain of non human primate. The release of endogenous morphine from monkey brain slices was studied in vitro in the presence of high potassium concentrations with and without calcium in the medium. Endogenous morphine, and its direct precursor codeine, was for the first time detected by GC/MS in the brain of non human primate. High potassium concentrations depolarized neurons releasing endogenous morphine twofold above basal line levels in a calcium dependent mechanism. This finding confirms the presence of the endogenous alkaloid throughout the phylogenesis of the nerve system of mammals and lower animals and indicates that endogenous morphine might function ...
Medical science monitor : international medical journal of experimental and clinical research, 2005
Endogenous morphine and proopiomelanocortin-derived peptide-like molecules were identified in mol... more Endogenous morphine and proopiomelanocortin-derived peptide-like molecules were identified in molluscan tissues, including the nervous system, supporting their ancient phylogeny. Their presence and function in "simple" animals, demonstrates their involvement in mechanisms underlying the stress response, preceding the mammalian neuroendocrine axis. Immunocytochemical analysis was used to study the localization of morphine- and adrenocorticotropic hormone (ACTH)-like material in the nervous system of Planorbarius corneus, Mytilus galloprovincialis, Lymnaea stagnalis and Viviparus ater. Acute stress experiments were performed on P. corneus and, by radioimmune assay, we quantified the expression of an ACTH-like peptide in control and stressed animals. We demonstrate that in mollusks the presence of a morphine-like compound is differentially distributed in neuronal structures containing an ACTH-like molecule. In P. corneus, the two immunoreactivities appear to be colocalized in...
Cultures of isolated neuronal populations from the central ganglia of the gastropod mollusc Plano... more Cultures of isolated neuronal populations from the central ganglia of the gastropod mollusc Planorbarius corneus were used for testing the effects of inorganic lead. The examined parameters were cell survival, neurite outgrowth and cytoskeletal morphology. In large heterogeneous neuronal populations as obtained from a whole cerebral or pedal ganglion, the different sensitivity to lead is reflected mainly on the cell survival. The neurons belonging to the homogeneous E cluster population are more sensitive; in fact a higher percentage of them do not survive in the presence of lead. Moreover, in this neuronal cell type the neurite outgrowth is dramatically affected by lead only when the neurons are cultured on conditioned substrate. Possibly, membrane mechanisms activated for the neurite outgrowth represent a target for inorganic lead. The few neurites sprouted in presence of lead do not evidence changes in the cytoskeletal components.
Insulin receptor-like immunoreactivity (IR) was investigated in the central ganglia of different ... more Insulin receptor-like immunoreactivity (IR) was investigated in the central ganglia of different gastropod molluscs using a monoclonal antiserum raised against an epitope of the human placental insulin receptor. A well detectable and clear location of immunoreactive material was mainly found in the CNS of the freshwater snails Planorbarius corneus and Lymnaea stagnalis. This evidence correlates quite suggestively with the occurrence in these snails of a molluscan insulin peptide (MIP) previously shown. The widespread and discrete distribution of IR over a variety of physiologically distinct regions of P. corneus and L. stagnalis ganglia argues that these "receptors" may modulate multiple functions within the CNS.
E' stao effettuato uno screening immunocitochimico che ha dimostratyo la presenza nel sistema... more E' stao effettuato uno screening immunocitochimico che ha dimostratyo la presenza nel sistema nervoso gangliare del bivalve Venus di alcuni neurotrasmettitori e neuropeptidi, come i peptidi "CDC" implicati nel comporatamento riproduttivo dei gasteropodi e di altri bivalvi
1. Evidence supporting the presence in the invertebrate nervous system of a class of glial cells ... more 1. Evidence supporting the presence in the invertebrate nervous system of a class of glial cells resembling vertebrate microglia was obtained in the freshwater snail Planorbarius corneus. These cells are easily identified by their immunopositivity to anti-pro-opiomelanocortin (POMC)-derived peptide antibodies. 2. Invertebrate microglia, as in vertebrates, exhibit macrophage-like activity in vivo and in cell cultures. These cells respond to the trauma of ganglionic excision and their organotypic culture by leaving their location around neurons and moving to the lesion site from which they migrate in the culture dish. 3. In vitro, these microglia undergo conformational changes and show phagocytic properties in the presence of bacteria or lipopolysaccharide. The activated cells also express tumor necrosis factor-alpha-like material and an increase in nitric oxide synthase, as shown by immunocytochemistry. 4. The inhibitory effect of morphine on the mobility and phagocytic activity of invertebrate microglia provide additional functional evidence for a possible role of opiate-like compounds in downregulating immunoregulatory processes, as also observed in the circulating immunocytes.
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Papers by Dario Sonetti