Whole body withdrawal circuit and its involvement in the behavioral hierarchy of the mollusk Clione limacina

1996 ◽  
Vol 75 (2) ◽  
pp. 529-537 ◽  
Author(s):  
T. P. Norekian ◽  
R. A. Satterlie
Keyword(s):  
Feeding Behavior ◽  
Motor Neurons ◽  
Prey Capture ◽  
The Body ◽  
Whole Body ◽  
High Threshold ◽  
Behavioral Repertoire ◽  
Withdrawal Behavior ◽  
Cerebral Neurons ◽  
Clione Limacina

1. The behavioral repertoire of the holoplanktonic pteropod mollusk Clione limacina includes a few well-defined behaviors organized in a priority sequence. Whole body withdrawal takes precedence over slow swimming behavior, whereas feeding behavior is dominant over withdrawal. In this study a group of neurons is described in the pleural ganglia, which controls whole body withdrawal behavior in Clione. Each pleural withdrawal (Pl-W) neuron has a high threshold for spike generation and is capable of inducing whole body withdrawal in a semi-intact preparation: retraction of the body-tail, wings, and head. Each Pl-W neuron projects axons into the main central nerves and innervates all major regions of the body. 2. Stimulation of Pl-W neurons produces inhibitory inputs to swim motor neurons that terminate swimming activity in the preparation. In turn, Pl-W neurons receive inhibitory inputs from the cerebral neurons involved in the control of feeding behavior in Clione, neurons underlying extrusion of specialized prey capture appendages. Thus it appears that specific inhibitory connections between motor centers can explain the dominance of withdrawal behavior over slow swimming and feeding over withdrawal in Clione.

Cerebral serotonergic neurons reciprocally modulate swim and withdrawal neural networks in the mollusk Clione limacina

1996 ◽  
Vol 75 (2) ◽  
pp. 538-546 ◽  
Author(s):  
T. P. Norekian ◽  
R. A. Satterlie
Keyword(s):  
Neural Networks ◽  
Motor Neurons ◽  
Swimming Behavior ◽  
Whole Body ◽  
Inhibitory Effects ◽  
Serotonergic Neurons ◽  
Serotonin Antagonist ◽  
Cerebral Ganglia ◽  
Cerebral Neurons ◽  
Clione Limacina

1. A pair of serotonin-immunoreactive neurons has been identified in the cerebral ganglia of the pteropod mollusk Clione limacina, which produce coordinated, excitatory/inhibitory effects on neurons controlling two incompatible behaviors, swimming and whole body withdrawal. These cells were designated cerebral serotonergic ventral (Cr-SV) neurons. 2. Activation of Cr-SV neurons produces a prominent inhibition of the pleural withdrawal neurons, which have been previously shown to induce whole body withdrawal in Clione. In addition, the cerebral neurons produce weak excitatory inputs to swim motor neurons, pedal serotonergic neurons involved in the peripheral modulation of swimming, and to the serotonergic heart excitor neuron. 3. Inhibitory and excitatory effects appear to be produced by serotonin because they are mimicked by exogenous serotonin and are blocked by the serotonin antagonist mianserin. 4. All serotonergic neurons identified thus far in the CNS of Clione appear to function in a coordinated manner, altering a variety of neural centers all directed toward the activation of swimming behavior.

Pharmacologically induced elements of the hunting and feeding behavior in the pteropod mollusk Clione limacina. I. Effects of GABA

1993 ◽  
Vol 69 (2) ◽  
pp. 512-521 ◽  
Author(s):  
Y. I. Arshavsky ◽  
T. G. Deliagina ◽  
G. N. Gamkrelidze ◽  
G. N. Orlovsky ◽  
Y. V. Panchin ◽  
...  
Keyword(s):  
Feeding Behavior ◽  
Motor Neurons ◽  
Gabab Receptors ◽  
Gamma Aminobutyric Acid ◽  
Rhythmic Movements ◽  
Rhythm Generator ◽  
Buccal Ganglia ◽  
Gabaa Receptor Antagonist ◽  
Feeding Rhythm ◽  
Clione Limacina

1. The pteropod mollusk Clione limacina is a predator, feeding on the small pteropod mollusk Limacina helicina. Injection of gamma-aminobutyric acid (GABA) into the hemocoel of the intact Clione evoked some essential elements of the hunting and feeding behavior, i.e., protracting the tentacles, opening the mouth, and triggering the rhythmic movements of the buccal mass. This pattern resembled that evoked by presentation of the prey: Clione grasped the Limacina by its tentacles, extracted the prey's body from the shell and then swallowed it. 2. In electrophysiological experiments, several targets of GABA action have been found: 1) direct application of GABA to isolated cerebral motor neurons projecting to the protractor muscles of tentacles resulted in their excitation; 2) GABA activated the feeding rhythm generator located in the buccal ganglia; 3) GABA exerted excitatory or inhibitory effects on the receptor cells of statocysts, the effects being mediated by the efferent input to these cells; 4) GABA suppressed the defense reaction, which is an inhibition of the locomotor activity and of tentacle motor neurons, arising in response to stimulation of the head afferents; and 5) GABA potentiated an excitatory action of the serotoninergic metacerebral cells on the feeding rhythm generator. 3. Effects of GABA on the tentacle motor neurons and the feeding rhythm generator are pharmacologically distinguishable. The action of GABA on the feeding rhythm generator was mimicked by baclofen (which activates the GABAB receptors in mammalian neurons) and was not sensitive to bicuculline (the GABAA receptor antagonist in mammals). On the other hand, bicuculline competitively inhibited the GABA-induced excitation of the tentacle motor neurons. 4. GABAergic neurons have been located in the cerebral, pedal, and buccal ganglia by means of immunohistochemical methods.

scholarly journals Serotonergic modulation of swimming speed in the pteropod mollusc Clione limacina. III. Cerebral neurons.

1995 ◽  
Vol 198 (4) ◽  
pp. 917-930 ◽  
Author(s):  
R A Satterlie ◽  
T P Norekian
Keyword(s):  
Motor Neurons ◽  
Time Course ◽  
Neuron Activity ◽  
Target Cells ◽  
Cellular Mechanisms ◽  
Cycle Frequency ◽  
Course Of Action ◽  
Cell Groups ◽  
Cerebral Neurons ◽  
Clione Limacina

Swim acceleration in Clione limacina can occur via central inputs to pattern generator interneurons and motor neurons and through peripheral inputs to the swim musculature. In the previous paper, peripheral modulation of the swim muscles was shown to increase wing contractility. In the present paper, central inputs are described that trigger an increase in swim frequency and an increase in motor neuron activity. In dissected preparations, spontaneous acceleration from slow to fast swimming included an increase in the cycle frequency, a baseline depolarization in the swim interneurons and an increase in the intensity of motoneuron firing. Similar effects could be elicited by bath application of 10(-5) mol l-1 serotonin. Two clusters of cerebral serotonin-immunoreactive interneurons were found to produce acceleration of swimming accompanied by changes in neuronal activity. Posterior cluster neurons triggered an increase in swim frequency, depolarization of the swim interneurons, an increase in general excitor motoneuron activity and activation of type 12 interneurons and pedal peripheral modulatory neurons. Cells from the anterior cerebral cluster also increased swim frequency, increased activity in the swim motoneurons and activated type 12 interneurons, pedal peripheral modulatory neurons and the heart excitor neuron. The time course of action of the anterior cluster neurons did not greatly outlast the duration of spike activity, while that of the posterior cluster neurons typically outlasted burst duration. It appears that the two discrete clusters of serotonin-immunoreactive neurons have similar, but not identical, effects on swim neurons, raising the possibility that the two serotonergic cell groups modulate the same target cells through different cellular mechanisms.

Coordinated Excitatory Effect of GABAergic Interneurons on Three Feeding Motor Programs in the Mollusk Clione limacina

2005 ◽  
Vol 93 (1) ◽  
pp. 305-315 ◽  
Author(s):  
Tigran P. Norekian ◽  
Aleksey Y. Malyshev
Keyword(s):  
Neural Networks ◽  
Feeding Behavior ◽  
Prey Capture ◽  
Order System ◽  
Dependent Manner ◽  
Rhythmic Movements ◽  
Excitatory Effect ◽  
Double Labeling ◽  
The Neural Networks ◽  
Clione Limacina

Coordination between different motor centers is essential for the orderly production of all complex behaviors. Understanding the mechanisms of such coordination during feeding behavior in the carnivorous mollusk Clione limacina is the main goal of the current study. A bilaterally symmetrical interneuron identified in the cerebral ganglia and designated Cr-BM neuron produced coordinated activation of neural networks controlling three main feeding structures: prey capture appendages called buccal cones, chitinous hooks used for prey extraction from the shell, and the toothed radula. The Cr-BM neuron produced strong excitatory inputs to motoneurons controlling buccal cone protraction. It also induced a prominent activation of the neural networks controlling radula and hook rhythmic movements. In addition to the overall activation, Cr-BM neuron synaptic inputs to individual motoneurons coordinated their activity in a phase-dependent manner. The Cr-BM neuron produced depolarizing inputs to the radula protractor and hook retractor motoneurons, which are active in one phase, and hyperpolarizing inputs to the radula retractor and hook protractor motoneurons, which are active in the opposite phase. The Cr-BM neuron used GABA as its neurotransmitter. It was found to be GABA-immunoreactive in the double-labeling experiments. Exogenous GABA mimicked the effects produced by Cr-BM neuron on the postsynaptic neurons. The GABA antagonists bicuculline and picrotoxin blocked Cr-BM neuron-induced PSPs. The prominent coordinating effect produced by the Cr-BM neuron on the neural networks controlling three major elements of the feeding behavior in Clione suggests that this interneuron is an important part of the higher-order system for the feeding behavior.

A Simple and Inexpensive Clinical Whole Body Counter

1976 ◽  
Vol 15 (05) ◽  
pp. 248-253
Author(s):  
A. K. Basu ◽  
S. K. Guha ◽  
B. N. Tandon ◽  
M. M. Gupta ◽  
M. ML. Rehani
Keyword(s):  
The Body ◽  
Whole Body ◽  
Vitro Assay ◽  
Body Counter ◽  
Optimum Parameters ◽  
Whole Body Counter ◽  
Single Detector ◽  
Background Index ◽  
Iodide Crystal

SummaryThe conventional radioisotope scanner has been used as a whole body counter. The background index of the system is 10.9 counts per minute per ml of sodium iodide crystal. The sensitivity and derived sensitivity parameters have been evaluated and found to be suitable for clinical studies. The optimum parameters for a single detector at two positions above the lying subject have been obtained. It has been found that for the case of 131I measurement it is possible to assay a source located at any point in the body with coefficient of variation less than 5%. To add to the versatility, a fixed geometry for in-vitro counting of large samples has been obtained. The retention values obtained by the whole body counter have been found to correlate with those obtained by in-vitro assay of urine and stool after intravenous administration of 51Cr-albumin.

Visualization of Invasion into the Body and Internal Diffusion of Nanoparticles

2008 ◽  
Vol 396-398 ◽  
pp. 569-572
Author(s):  
Fumio Watari ◽  
Shigeaki Abe ◽  
I.D. Rosca ◽  
Atsuro Yokoyama ◽  
Motohiro Uo ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Fluorescent Microscopy ◽  
The Body ◽  
Internal Diffusion ◽  
Whole Body ◽  
X Ray ◽  
Body Level ◽  
Organ Level ◽  
Level 2 ◽  
Internal Body

Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.

scholarly journals Making the choice between bioelectrical impedance measures for body hydration status assessment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dmitry M. Davydov ◽  
Andrey Boev ◽  
Stas Gorbunov
Keyword(s):  
Body Schema ◽  
Bioelectrical Impedance ◽  
Information Criterion ◽  
The Body ◽  
Whole Body ◽  
Hydration Status ◽  
Status Assessment ◽  
Best Fitting ◽  
Body Compartments ◽  
Fitting In

AbstractSituational or persistent body fluid deficit (i.e., de- or hypo-hydration) is considered a significant health risk factor. Bioimpedance analysis (BIA) has been suggested as an alternative to less reliable subjective and biochemical indicators of hydration status. The present study aimed to compare various BIA models in the prediction of direct measures of body compartments associated with hydration/osmolality. Fish (n = 20) was selected as a biological model for physicochemically measuring proximate body compartments associated with hydration such as water, dissolved proteins, and non-osseous minerals as the references or criterion points. Whole-body and segmental/local impedance measures were used to investigate a pool of BIA models, which were compared by Akaike Information Criterion in their ability to accurately predict the body components. Statistical models showed that ‘volumetric-based’ BIA measures obtained in parallel, such as distance2/Rp, could be the best approach in predicting percent of body moisture, proteins, and minerals in the whole-body schema. However, serially-obtained BIA measures, such as the ratio of the reactance to resistance and the resistance adjusted for distance between electrodes, were the best fitting in predicting the compartments in the segmental schema. Validity of these results should be confirmed on humans before implementation in practice.

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