ABSTRACT
The reorganization of the ventral nerve cord (VNC) during metamorphosis of M. quadrifasciata was observed to be characterized by shortening of connectives and subsequent fusion of the 2nd and 3rd thoracic and the 1st abdominal ganglia. Also, the 5th to 7th abdominal ganglia came into very close contact. These changes were accompanied by increasing levels of endogenous ecdysteroids, as determined by a radioimmunoassay. Incubation of VNC in the presence of 5 microg 20-hydroxyecdysone, caused significant shortening of connectives in the thoracic region, but not in the abdomen, evidencing a segment-specific response to this hormone. Cell death in the ventral ganglia was revealed by transmission electron microscopy and TUNEL-reaction. Detection of labeled cells in the region where contiguous ganglia come into close contact suggests that programmed cell death is involved in ganglionic fusion.
Subject(s)
Apoptosis , Bees/physiology , Ecdysteroids/metabolism , Nerve Tissue/physiology , Nerve Tissue/ultrastructure , Peripheral Nervous System/physiology , Peripheral Nervous System/ultrastructure , Animals , In Situ Nick-End Labeling , Metamorphosis, Biological , Microscopy, Electron , Radioimmunoassay , Time FactorsABSTRACT
Mast cells are connective tissue cells, present in all vertebrates and characterized by the metachromatic stain of their granules. Nowadays mast cells have been recognized as a potent cellular source of multiple cytokines, suggesting an important role in immunoregulation and host defense. These cells have been described as preferentially located around blood vessels but more recently close spatial relationship between mast cells and nerves has been reported mostly in mammalian species. The microanatomy of nerve tissue and associated mast cells in the toad Bufo marinus tongue have been studied here by means of high resolution light microscopy. Mast cell population was identified by the metachromatic staining of their cytoplasm granules in Epon embedded semithin sections counterstained with Toluidine Blue and Azure A. Numerous mast cells were observed scattered throughout the submucosal region, adjacent and/or within of nerve bundles and nerve ganglia, near skeletal muscle fibers and adjacent of blood vessels. Additionally, mast cells adjacent to single but conspicuous myelinated nerve fibers were seen under endothelia of lymphatic vessels wall and this is apparently a unreported event. Results suggest nerve-mast cell associations are functionally important in the toad tongue.
Subject(s)
Bufo marinus/anatomy & histology , Mast Cells/ultrastructure , Nerve Tissue/ultrastructure , Tongue/cytology , Tongue/innervation , Animals , Lingual Nerve/ultrastructure , Male , Tongue/ultrastructureSubject(s)
Humans , Male , Female , Nerve Tissue/ultrastructure , Bone and Bones/ultrastructure , Connective Tissue/ultrastructure , Adipose Tissue/ultrastructure , Cells/ultrastructure , Lymphatic System/ultrastructure , Digestive System/ultrastructure , Respiratory System/ultrastructure , Urogenital System/ultrastructure , Endocrine Glands/ultrastructure , Skin/ultrastructure , Sense Organs/ultrastructureABSTRACT
Un texto completo, excelentemente ilustrado sobre el tema: Organización general, estructura y origen del sistema nervioso. El sistema nervioso central y sus envolturas:cráneo y raquis. Médula espinal. Tronco encefálico. Cerebelo. Desarrollo del cerebro. Diencéfalo. Hemisferios cerebrales. Corteza cerebral. Circulación encefálica. Topografía craneoencefálica. El sistema nervioso periferico. Organización anatomo-funcional del sistema nervioso
Subject(s)
Neuroanatomy/education , Nervous System/anatomy & histology , Nerve Tissue/anatomy & histology , Cerebellum/anatomy & histology , Cerebellum/embryology , Cerebellum/blood supply , Spine/anatomy & histology , Spine/embryology , Skull/anatomy & histology , Skull/embryology , Cerebrum/anatomy & histology , Cerebrum/embryology , Cerebrum/blood supply , Diencephalon/anatomy & histology , Diencephalon/embryology , Subarachnoid Space/anatomy & histology , Meninges/anatomy & histology , Meninges/embryology , Autonomic Nervous System/anatomy & histology , Autonomic Nervous System/embryology , Autonomic Nervous System/blood supply , Central Nervous System/anatomy & histology , Central Nervous System/embryology , Central Nervous System/blood supply , Nervous System/embryology , Nerve Tissue/ultrastructure , Cerebral Ventricles/anatomy & histology , Cerebral Ventricles/embryologyABSTRACT
Un texto completo, excelentemente ilustrado sobre el tema: Organización general, estructura y origen del sistema nervioso. El sistema nervioso central y sus envolturas:cráneo y raquis. Médula espinal. Tronco encefálico. Cerebelo. Desarrollo del cerebro. Diencéfalo. Hemisferios cerebrales. Corteza cerebral. Circulación encefálica. Topografía craneoencefálica. El sistema nervioso periferico. Organización anatomo-funcional del sistema nervioso