Asymmetrical Effect of GABA on the Postural Orientation inClione

2000 ◽  
Vol 84 (3) ◽  
pp. 1673-1676 ◽  
Author(s):  
T. G. Deliagina ◽  
G. N. Orlovsky ◽  
A. I. Selverston ◽  
Y. I. Arshavsky
Keyword(s):  
Body Orientation ◽  
In Vitro Experiments ◽  
Marine Mollusk ◽  
Left Group ◽  
Asymmetrical Effect ◽  
Postural Orientation ◽  
Left And Right ◽  
Clione Limacina ◽  
The Right

The marine mollusk Clione limacina, when swimming, normally stabilizes the vertical body orientation by means of the gravitational tail reflexes. Horizontal swimming or swimming along inclined ascending trajectories is observed rarely. Here we report that GABA injection into intact Clione resulted in a change of the stabilized orientation and swimming with a tilt of ∼45° to the left. The analysis of modifications in the postural network underlying this effect was done with in vitro experiments. The CNS was isolated together with the statocysts. Spike discharges in the axons of two groups of motoneurons responsible for the left and right tail flexion, as well as in the axons of CPB3 interneurons mediating signals from the statocyst receptors to the motoneurons, were recorded extracellularly when the preparation was rotated in space. Normally the tail motoneurons of the left and right groups were activated with the contralateral tilt of the preparation. Under the effect of GABA, the gravitational responses in the right group of motoneurons and in the corresponding interneurons were dramatically reduced while the responses in the left group remained unchanged. The most likely site of the inhibitory GABA action is the interneurons mediating signals from the statocysts to the right group of tail motoneurons. The GABA-induced asymmetry of the left and right gravitational tail reflexes, observed in the in vitro experiments, is consistent with a change of the stabilized orientation caused by GABA in the intact Clione.

Dual Sensory-Motor Function for a Molluskan Statocyst Network

2004 ◽  
Vol 91 (1) ◽  
pp. 336-345 ◽  
Author(s):  
R. Levi ◽  
P. Varona ◽  
Y. I. Arshavsky ◽  
M. I. Rabinovich ◽  
A. I. Selverston
Keyword(s):  
Search Behavior ◽  
Motor Program ◽  
Hunting Behavior ◽  
Marine Mollusk ◽  
Receptor Cells ◽  
Motor Nerves ◽  
Clione Limacina ◽  
Biologically Based Model

In mollusks, statocyst receptor cells (SRCs) interact with each other forming a neural network; their activity is determined by both the animal's orientation in the gravitational field and multimodal inputs. These two facts suggest that the function of the statocysts is not limited to sensing the animal's orientation. We studied the role of the statocysts in the organization of search motion during hunting behavior in the marine mollusk, Clione limacina. When hunting, Clione swims along a complex trajectory including numerous twists and turns confined within a definite space. Search-like behavior could be evoked pharmacologically by physostigmine; application of physostigmine to the isolated CNS produced “fictive search behavior” monitored by recordings from wing and tail nerves. Both in behavioral and in vitro experiments, we found that the statocysts are necessary for search behavior. The motor program typical of searching could not be produced after removing the statocysts. Simultaneous recordings from single SRCs and motor nerves showed that there was a correlation between the SRCs activity and search episodes. This correlation occurred even though the preparation was fixed and, therefore the sensory stimulus was constant. The excitation of individual SRCs could in some cases precede the beginning of search episodes. A biologically based model showed that, theoretically, the hunting search motor program could be generated by the statocyst receptor network due to its intrinsic dynamics. The results presented support for the idea that the statocysts are actively involved in the production of the motor program underlying search movements during hunting behavior.

scholarly journals Developmental Brain Asymmetry. The Good and the Bad Sides

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 128
Author(s):  
Monica Laura Cara ◽  
Ioana Streata ◽  
Ana Maria Buga ◽  
Dominic Gabriel Iliescu
Keyword(s):  
Time Window ◽  
Brain Asymmetry ◽  
Brain Lateralization ◽  
Brain Hemispheres ◽  
Left And Right ◽  
Vitro Model ◽  
New Biomarkers ◽  
The Right ◽  
Neuropsychiatric Conditions

Brain asymmetry is a hallmark of the human brain. Recent studies report a certain degree of abnormal asymmetry of brain lateralization between left and right brain hemispheres can be associated with many neuropsychiatric conditions. In this regard, some questions need answers. First, the accelerated brain asymmetry is programmed during the pre-natal period that can be called “accelerated brain decline clock”. Second, can we find the right biomarkers to predict these changes? Moreover, can we establish the dynamics of these changes in order to identify the right time window for proper interventions that can reverse or limit the neurological decline? To find answers to these questions, we performed a systematic online search for the last 10 years in databases using keywords. Conclusion: we need to establish the right in vitro model that meets human conditions as much as possible. New biomarkers are necessary to establish the “good” or the “bad” borders of brain asymmetry at the epigenetic and functional level as early as possible.

Endothelium-dependent relaxation differs in porcine pulmonary arteries from the left and right caudal lobes

2000 ◽  
Vol 88 (3) ◽  
pp. 827-834 ◽  
Author(s):  
Lynelle R. Johnson ◽  
John R. Dodam ◽  
M. Harold Laughlin
Keyword(s):  
Sodium Nitroprusside ◽  
Pulmonary Arteries ◽  
Smooth Muscle Contraction ◽  
Lower Drug ◽  
Left And Right ◽  
The Difference ◽  
The Right ◽  
Oxide Synthase ◽  
Lung Lobes

We hypothesized that pulmonary arteries (PA) from identical branch orders within left and right caudal lung lobes would exhibit similar vasomotor responses. Arterial rings from caudal lung lobes of female swine were examined in vitro. Vascular smooth muscle contraction to KCl and norepinephrine did not differ. Vascular relaxation to endothelium-dependent (bradykinin, acetylcholine, A-23187) and -independent (sodium nitroprusside, zero-calcium Krebs solution) vasodilators was assessed. Right PA exhibited less maximal relaxation to acetylcholine (50%) than did left PA (69%; P< 0.001). Maximal relaxation to sodium nitroprusside did not differ, although right PA had a lower drug concentration resulting in half-maximal relaxation (6.26 × 10−8M) than did left PA (9.57 × 10−8 M; P< 0.05). Nitric oxide synthase inhibition with an arginine analog ( N ω-nitro-l-arginine methyl ester) depressed acetylcholine-induced relaxation but the left vs. right difference persisted. Indomethacin enhanced relaxation to acetylcholine and abolished the difference between left and right. We conclude that endothelium-dependent vasorelaxation is less in porcine right than in left PA because of greater release of one or more constricting prostanoids in arteries from the right caudal lobe.

Biaxial mechanical properties of the pericardium in normal and volume overload dogs

1985 ◽  
Vol 249 (2) ◽  
pp. H222-H230 ◽  
Author(s):  
M. C. Lee ◽  
M. M. LeWinter ◽  
G. Freeman ◽  
R. Shabetai ◽  
Y. C. Fung
Keyword(s):  
Mechanical Properties ◽  
Volume Overload ◽  
Physiological Saline ◽  
Aortocaval Shunt ◽  
Tension Level ◽  
Left And Right ◽  
The Right ◽  
Biaxial Mechanical Properties ◽  
Cardiac Dilatation

The two-dimensional mechanical properties of the pericardium from dogs with a normal or chronically enlarged heart were studied in vitro. A 3.0-cm-square piece of the pericardium overlying the right and/or left ventricle was excised. An approximately 1.0-cm-square target was marked at the center, and its dimension was measured electrooptically. When immersed in physiological saline at 37 degrees C, the specimen was stretched and unloaded sinusoidally in one direction while force in the transverse direction was held constant. The tension-stretch relationship was highly reproducible and was insensitive to strain rate in the range of 0.002-0.1 Hz. Hysteresis was present. The pericardium was mostly anisotropic; however, the direction of maximal compliance varied among dogs. The elastic properties of the pericardium overlying the left and right ventricles were the same in most cases. Substantial stress relaxation was observed; in contrast, insignificant creep developed over 30 min. In five dogs with chronic cardiac dilatation due to an infrarenal aortocaval shunt, the tension-stretch curves were shifted significantly to the right (i.e., greater deformation at the same tension level). However, the pericardial viscoelastic properties and thickness were unchanged. In other words, chronic cardiac dilatation resulted in a more compliant pericardium.

Heterogeneity of action potential durations in isolated mouse left and right atria recorded using voltage-sensitive dye mapping

2004 ◽  
Vol 287 (6) ◽  
pp. H2634-H2643 ◽  
Author(s):  
Anders Nygren ◽  
Alan E. Lomax ◽  
Wayne R. Giles
Keyword(s):  
Action Potential ◽  
Left Atrium ◽  
Right Atrium ◽  
Imaging System ◽  
Mouse Heart ◽  
Muscarinic Agonist ◽  
Voltage Sensitive Dye ◽  
Left And Right ◽  
The Right

An imaging system for di-4-ANEPPS (4-[β-[2-(di- n-butylamino)-6-naphthylvinyl]pyridinium]) voltage-sensitive dye recordings has been adapted for recording from an in vitro mouse heart preparation that consists of both atria in isolation. This approach has been used to study inter- and intra-atrial activation and conduction and to monitor action potential durations (APDs) in the left and right atrium. The findings from this study confirm some of our previous findings in isolated mouse atrial myocytes and demonstrate that many electrophysiological properties of mouse atria closely resemble those of larger mammals. Specifically, we made the following observations: 1) Activation in mouse atria originates in the sinoatrial node and spreads into the right atrium and, after a delay, into the left atrium. 2) APD in the left atrium is shorter than in the right atrium. 3) Sites in the posterior walls have longer APDs than sites in the atrial appendages. 4) Superfusion of this preparation with 4-aminopyridine and tetraethylammonium resulted in increases in APD, consistent with their inhibitory effects on the K+ currents known to be expressed in mouse atria. 5) The muscarinic agonist carbachol shortened APD in all areas of the preparation, except the left atrial appendage, in which carbachol had no statistically significant effect on APD. These results validate a new approach for monitoring activation, conduction, and repolarization in mouse atria and demonstrate that the physiological and pharmacological properties of mouse atria are sufficiently similar to those of larger animals to warrant further studies using this preparation.

Participation of an Unpaired Motor Neurone in the Bilaterally Organized Oesophageal Rhythm in the Lobsters Jasus Lalandii and Palinurus Vulgaris

1981 ◽  
Vol 90 (1) ◽  
pp. 205-230
Author(s):  
M. MOULINS ◽  
F. NAGY
Keyword(s):  
Cell Body ◽  
Motor Neurone ◽  
The Other ◽  
Rock Lobster ◽  
Tonic Activation ◽  
Left And Right ◽  
Motor Rhythm ◽  
Pass Through ◽  
The Right

1. The main oesophageal motor neurone (OD1) of the rock lobster is an unpaired bifurcating nerve cell. The cell body is located in the oesophageal ganglion and the left and right axonal branches pass through the left and right commissural ganglia to innervate all the oesophageal dilator muscles. 2. Three types of potentials are recorded in the cell body in vitro; each type is associated with an extracellular spike recorded from the nerves connecting the ganglia. 3. Comparison between the three types of potentials (and the extracellular spikes) and collision experiments shows that all three are spikes. 4. Spontaneous collisions can sometimes occur and it is concluded that one spike is generated in the oesophageal ganglion (somatofugal a-spike) while the other two are generated in the left commissural ganglion (somatopetal c-spike) or the right commissural ganglion (somatopetal c-spike). 5. Each spike initiating zone is synaptically driven. 6. The commissural zones fire short phasic bursts; each burst is composed of only one type of spike (b- or c-). The oesophageal (a-) zone gives a tonic discharge interrupted when the other zones are firing. Finally, combined firing of the spike initiating zones can generate three different patterns of discharge. 7. OD1 participates in the oesophageal motor rhythm produced by two oscillators (one in each commissural ganglion) which fire alternated series of bursts. 8. It is concluded that the three axonal spike initiating zones enable the motor neurone (1) to follow the oesophageal motor rhythm at any time regardless of which oscillator is in operation and (2) to co-ordinate phasic and tonic activation of the oesophageal dilator muscles.

Neurofilaments and Paired Helical Filaments

1985 ◽  
Vol 43 ◽  
pp. 740-743
Author(s):  
J. Metuzals
Keyword(s):  
Animal Model ◽  
Posttranslational Modifications ◽  
Posttranslational Modification ◽  
Giant Axon ◽  
Paired Helical Filaments ◽  
Squid Giant Axon ◽  
In Vitro Experiments ◽  
Thin Sections ◽  
Structural Relationships

It has been demonstrated that the neurofibrillary tangles in biopsies of Alzheimer patients, composed of typical paired helical filaments (PHF), consist also of typical neurofilaments (NF) and 15nm wide filaments. Close structural relationships, and even continuity between NF and PHF, have been observed. In this paper, such relationships are investigated from the standpoint that the PHF are formed through posttranslational modifications of NF. To investigate the validity of the posttranslational modification hypothesis of PHF formation, we have identified in thin sections from frontal lobe biopsies of Alzheimer patients all existing conformations of NF and PHF and ordered these conformations in a hypothetical sequence. However, only experiments with animal model preparations will prove or disprove the validity of the interpretations of static structural observations made on patients. For this purpose, the results of in vitro experiments with the squid giant axon preparations are compared with those obtained from human patients. This approach is essential in discovering etiological factors of Alzheimer's disease and its early diagnosis.

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

Enhanced Increases in Cytosolic Ca2+ in ADP-Stimulated Platelets from Patients with Delta-Storage Pool Deficiency – A Possible Indicator of Interactions between Granule-Bound ADP and the Membrane ADP Receptor

1997 ◽  
Vol 77 (02) ◽  
pp. 376-382 ◽  
Author(s):  
Bruce Lages ◽  
Harvey J Weiss
Keyword(s):  
Platelet Rich Plasma ◽  
Limited Range ◽  
Dense Granule ◽  
Receptor Desensitization ◽  
Fura 2 ◽  
Storage Pool ◽  
Low Levels ◽  
The Right

SummaryThe possible involvement of secreted platelet substances in agonist- induced [Ca2+]i increases was investigated by comparing these increases in aspirin-treated, fura-2-loaded normal platelets and platelets from patients with storage pool deficiencies (SPD). In the presence and absence of extracellular calcium, the [Ca2+]i response induced by 10 µM ADP, but not those induced by 0.1 unit/ml thrombin, 3.3 µM U46619, or 20 µM serotonin, was significantly greater in SPD platelets than in normal platelets, and was increased to the greatest extent in SPD patients with Hermansky-Pudlak syndrome (HPS), in whom the dense granule deficiencies are the most severe. Pre-incubation of SPD-HPS and normal platelets with 0.005-5 µM ADP produced a dose-dependent inhibition of the [Ca2+]i response induced by 10 µ M ADP, but did not alter the [Ca2+]i increases induced by thrombin or U46619. Within a limited range of ADP concentrations, the dose-inhibition curve of the [Ca2+]i response to 10 µM ADP was significantly shifted to the right in SPD-HPS platelets, indicating that pre-incubation with greater amounts of ADP were required to achieve the same extent of inhibition as in normal platelets. These results are consistent with a hypothesis that the smaller ADP-induced [Ca2+]i increases seen in normal platelets may result from prior interactions of dense granule ADP, released via leakage or low levels of activation, with membrane ADP receptors, causing receptor desensitization. Addition of apyrase to platelet-rich plasma prior to fura-2 loading increased the ADP-induced [Ca2+]i response in both normal and SPD-HPS platelets, suggesting that some release of ADP derived from both dense granule and non-granular sources occurs during in vitro fura-2 loading and platelet washing procedures. However, this [Ca2+]i response was also greater in SPD-HPS platelets when blood was collected with minimal manipulation directly into anticoagulant containing apyrase, raising the possibility that release of dense granule ADP resulting in receptor desensitization may also occur in vivo. Thus, in addition to enhancing platelet activation, dense granule ADP could also act to limit the ADP-mediated reactivity of platelets exposed in vivo to low levels of stimulation.

Comparison of the efficiency of the indexes of Pont and Korkhause with Kernott technique in patients with narrowing of maxilla

2020 ◽  
Vol 20 (3) ◽  
pp. 199-203
Author(s):  
O. I. Admakin ◽  
I. A. Solop ◽  
A. D. Oksentyuk
Keyword(s):  
Dental Treatment ◽  
Standard Analysis ◽  
Clinical Hospital ◽  
Control Models ◽  
Diagnostic Models ◽  
Left And Right ◽  
The Asymmetry ◽  
The Right ◽  
The University ◽  
Medical University

Relevance. The narrowing of the maxilla is one of the most common pathologies in orthodontics. Recent studies show that the narrowing is always asymmetric which is connected to the rotation of the maxilla. To choose the treatment correctly one need a calculation that reveals the asymmetry, which is impossible with using standard indexes.Purpose – to compare efficiency of indexes of Pont and Korkhause with the Kernott's method in patients with narrowing of the maxilla.Materials and methods. The study involved 35 children aged from 8 to 12 years old undergoing dental treatment in the University Children's Clinical Hospital of the First Moscow State Medical University with no comorbidities. For every patient a gypsum model was prepared and after that to carry out the biometrical calculation. In this study two indexes were used: Pont's index and Korkhause's; using this standard analysis the narrowing of the maxilla was revealed. After using Pont's Index and Korkhaus analysis all the models were calculated by the method of Kernott with Kernott's dynamic pentagon.Results. As a result of the analysis of the control diagnostic models a narrowing of the maxilla in 69% of cases (n = 24) was revealed in all cases, the deviation of the size of the dentition was asymmetric. Thus, 65% of the surveyed models showed a narrowing on the right. This narrowing was of a different severity and averaged 15 control models.Conclusions. This shows that for the biometrics of diagnostic models it is necessary to use methods that allow to estimate the width of the dentition rows on the left and on the right separately. To correct the asymmetric narrowing of the dentition, it is preferable to use non-classical expanding devices that act equally on the left and right sides separetly.

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