Morphology and Histology of the Central Nervous System and Neurosecretory Cells in Melampus bidentatus Say (Gastropoda: Pulmonata)

1977 ◽  
Vol 96 (3) ◽  
pp. 295 ◽  
Author(s):  
Christopher H. Price
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neurosecretory Cells ◽  
The Central Nervous System ◽  
Melampus Bidentatus

The anatomy of neurosecretory neurones in the pond snail Lymnaea stagnalis (L)

1976 ◽  
Vol 274 (931) ◽  
pp. 169-202 ◽  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Lymnaea Stagnalis ◽  
Cell Types ◽  
Dark Field ◽  
Neurosecretory Cells ◽  
Pond Snail ◽  
Green Cell ◽  
The Central Nervous System ◽  
Dark Green

The anatomy of three neurosecretory cell types in the central nervous system (c.n.s.) of the gastropod mollusc Lymnaea stagnalis (L.) - the Dark Green Cells, Yellow Cells and Yellow-green Cells - has been studied by using bright and dark field illumination of material stained for neurosecretion by the Alcian Blue-Alcian Yellow technique. The neuronal geometry of single and groups of neurosecretory cells of the various types has been reconstructed from serial sections, and the likely destination of most of their processes has been determined. Dark Green Cells are monopolar, occur exclusively within the central nervous system (c.n.s.), have few or no branches terminating in neuropile, and send axons to the surface of the pleuro-parietal and pleuro-cerebral connectives. The majority of Dark Green Cell axons however (80- 85%), project down nerves which innervate ventral and anterior parts of the head-foot, the neck and the mantle. Dark Green Cell axons can be found in small nerves throughout these areas, and may terminate in a fine plexus of axons on the surfaces of the nerves. Since previous experimental work has shown that the Dark Green Cells are involved in osmotic or ionic regulation, these results suggest that the target organ of the Dark Green Cells may be the skin. Yellow Cells occur both within and outside the c.n.s. They are usually monopolar, but can be bipolar. They have several axons which normally arise separately from a single pole of the cell body, or close to it. One or more processes leave the cell proximal to the point where separate axons arise, and may run unbranched for some distance through neuropile before terminating in fine branches and blobs of various sizes. These branches may release hormone inside the c.n.s. Yellow-green Cells are mono-, bi- or multi-polar, and like the Yellow Cells are found both within and outside the c.n.s. Some Yellow-green Cells, though not all, have projections which terminate in neuropile in fine branches and blobs. Yellowgreen Cell bodies which occur in nerves can project back along the nerve into the c.n.s. The axons of Yellow Cells and Yellow-green Cells project to release sites in various ways. Some project into the connective tissue sheath of the c.n.s., which serves as a neurohaemal organ, either directly through the surface of a ganglion, or from the pleuro-cerebral or pleuro-parietal connectives. Other axons leave the c.n.s. via nerves leaving the left and right parietal and visceral ganglia; projections into the intestinal, anal, and internal right parietal nerves being most numerous. Axons which may be from either, or both Yellow Cells and Yellow-green Cells, can be found along the entire unbranched lengths of these nerves, and in subsequent branches which innervate organs lying in the anterior turn of the shell. All of these organs are closely associated with the lung cavity. The pattern of release of hormone which this arrangement implies may have been adopted to ensure a rapid distribution of hormone throughout the circulation following release, or to increase the concentration of hormone in blood flowing through target organs such as the kidney, lung walls or the heart.

scholarly journals The Obesity-Linked Gene Nudt3 Drosophila Homolog Aps Is Associated With Insulin Signaling

2015 ◽  
Vol 29 (9) ◽  
pp. 1303-1319 ◽  
Author(s):  
Michael J. Williams ◽  
Anders Eriksson ◽  
Muksheed Shaik ◽  
Sarah Voisin ◽  
Olga Yamskova ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Insulin Signaling ◽  
Association Studies ◽  
Neurosecretory Cells ◽  
Genome Wide Association Studies ◽  
Nudix Hydrolase ◽  
The Central Nervous System ◽  
Carbohydrate Levels ◽  
Median Neurosecretory Cells

Abstract Several genome-wide association studies have linked the Nudix hydrolase family member nucleoside diphosphate-linked moiety X motif 3 (NUDT3) to obesity. However, the manner of NUDT3 involvement in obesity is unknown, and NUDT3 expression, regulation, and signaling in the central nervous system has not been studied. We performed an extensive expression analysis in mice, as well as knocked down the Drosophila NUDT3 homolog Aps in the nervous system, to determine its effect on metabolism. Detailed in situ hybridization studies in the mouse brain revealed abundant Nudt3 mRNA and protein expression throughout the brain, including reward- and feeding-related regions of the hypothalamus and amygdala, whereas Nudt3 mRNA expression was significantly up-regulated in the hypothalamus and brainstem of food-deprived mice. Knocking down Aps in the Drosophila central nervous system, or a subset of median neurosecretory cells, known as the insulin-producing cells (IPCs), induces hyperinsulinemia-like phenotypes, including a decrease in circulating trehalose levels as well as significantly decreasing all carbohydrate levels under starvation conditions. Moreover, lowering Aps IPC expression leads to a decreased ability to recruit these lipids during starvation. Also, loss of neuronal Aps expression caused a starvation susceptibility phenotype while inducing hyperphagia. Finally, the loss of IPC Aps lowered the expression of Akh, Ilp6, and Ilp3, genes known to be inhibited by insulin signaling. These results point toward a role for this gene in the regulation of insulin signaling, which could explain the robust association with obesity in humans.

scholarly journals Neurosecretory Cells of the Central Nervous System of the Crab, Paratelphusa hydrodromous

1956 ◽  
Vol s3-97 (37) ◽  
pp. 75-82
Author(s):  
R. PARAMESWARAN
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Phase Contrast ◽  
Neutral Red ◽  
Neurosecretory Cells ◽  
Thoracic Ganglion ◽  
Contrast Microscope ◽  
The Central Nervous System ◽  
Secretory Products ◽  
The Brain

Three types of neurosecretory cells, designated A, B, and C, occur in the central nervous system of Paratelphusa hydrodromous. They are distinguishable by their sizes, the nature of their nuclei, and the secretory products in the cytoplasm. Their distribution and neurosecretory activity are recorded in this paper. All the three types occur in the thoracic ganglion, while the brain and tritocerebral connective ganglia contain only the A and B types. Examined alive under the phase-contrast microscope, the conspicuous A-cells reveal the presence of numerous tiny granules and dark spheroids in the cytoplasm. These spheroids are stainable by neutral red. In Golgi preparations the spheroid walls become black. These are sudanophil and probably represent lipochondria. The spheroids contain phospholipid and vitamin C. The granules of the cytoplasm probably represent the mitochondria. The brain and thoracic ganglia contain within them a rich network of delicate capillaries which surround individual neurosecretory cells as well as groups of cells. The secretory products are possibly discharged directly into the blood.

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