Functional Recoveries of Giant Interneurons in the Early Period after Unilateral Cercal Ablation in the Cricket Gryllus bimaculatus

2008 ◽  
Vol 25 (9) ◽  
pp. 931-936 ◽  
Author(s):  
Masamichi Kanou ◽  
Hiroyuki Kuroishi
Keyword(s):  
Early Period ◽  
Gryllus Bimaculatus ◽  
Giant Interneurons

scholarly journals Voltage-activated currents in identified giant interneurons isolated from adult crickets gryllus bimaculatus

1998 ◽  
Vol 201 (17) ◽  
pp. 2529-2541 ◽  
Author(s):  
P Kloppenburg ◽  
M Hörner
Keyword(s):  
Action Potentials ◽  
Gryllus Bimaculatus ◽  
Selective Labeling ◽  
Electrophysiological Properties ◽  
Giant Interneurons ◽  
Whole Cell Patch Clamp ◽  
Unequivocal Identification ◽  
Ionic Mechanisms ◽  
K Currents

The electrophysiological properties of cultured giant interneurons isolated from the terminal ganglion of adult crickets (Gryllus bimaculatus) were investigated using whole-cell patch-clamp techniques. To allow for unequivocal identification of these interneurons in cell culture, a protocol for fast and selective labeling of their cell bodies was established. Prior to cell dissociation, the giant interneurons were backfilled through their axons in situ with a fluorescent dye (dextran tetramethylrhodamine). In primary cell cultures, the cell bodies of giant interneurons were identified among a population of co-cultured neurons by their red fluorescence. Action potentials were recorded from the cell bodies of the cultured interneurons suggesting that several types of voltage-activated ion channels exist in these cells. Using voltage-clamp recording techniques, four voltage-activated currents were isolated and characterized. The giant interneurons express at least two distinct K+ currents: a transient current that is blocked by 4-aminopyridine (4x10(-3 )mol l-1) and a sustained current that is partially blocked by tetraethylammonium (3x10(-2 )mol l-1) and quinidine (2x10(-4 )mol l-1). In addition, a transient Na+ current sensitive to 10(-7 )mol l-1 tetrodotoxin and a Ca2+ current blocked by 5x10(-4 )mol l-1 CdCl2 have been characterized. This study represents the first step in an attempt to analyze the cellular and ionic mechanisms underlying plasticity in the well-characterized and behaviorally important giant interneuron pathway in insects.

Neuron-glia relationship during the early postembryonic development of the nervous system in some oligochaetes

1978 ◽  
Vol 36 (2) ◽  
pp. 600-601
Author(s):  
Wiktor Djaczenko ◽  
Carmen Calenda Cimmino
Keyword(s):  
Nervous System ◽  
Glial Cells ◽  
Early Period ◽  
Postembryonic Development ◽  
Ruthenium Red ◽  
The Body ◽  
Tubifex Tubifex ◽  
Growth Stages ◽  
Cell Processes ◽  
Cytoplasmic Processes

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

Image quality vs data obtainment in biological electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 42-43
Author(s):  
J. E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Beam ◽  
Image Quality ◽  
High Speed ◽  
Early Period ◽  
Early Years ◽  
Fluorescent Screen ◽  
Embedding Medium

In the early years of biological electron microscopy, scientists had their hands full attempting to describe the cellular microcosm that was suddenly before them on the fluorescent screen. Mitochondria, Golgi, endoplasmic reticulum, and other myriad organelles were being examined, micrographed, and documented in the literature. A major problem of that early period was the development of methods to cut sections thin enough to study under the electron beam. A microtome designed in 1943 moved the specimen toward a rotary “Cyclone” knife revolving at 12,500 RPM, or 1000 times as fast as an ordinary microtome. It was claimed that no embedding medium was necessary or that soft embedding media could be used. Collecting the sections thus cut sounded a little precarious: “The 0.1 micron sections cut with the high speed knife fly out at a tangent and are dispersed in the air. They may be collected... on... screens held near the knife“.

Direct Assessment of Effective Renal Plasma Flow from Renoscintigraphy with a Gamma Camera and an On-Line Computer

1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma
Keyword(s):  
Count Rate ◽  
Renal Plasma Flow ◽  
Early Period ◽  
Least Square Method ◽  
Least Square ◽  
Uptake Coefficient ◽  
Positive Linear Correlation ◽  
On Line ◽  
Best Fit ◽  
Plasma Activity

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the peak in the renoscintigraphic curve divided by the integral of the count-rate curve over the "blood"-ROI. A procedure for normalization of both curves against each other was also developed. The total kidney clearance of the hippurate was determined from the function of plasma activity concentration vs. time after a single injection; the determinations were made at 5, 10, 15, 20, 30, 45, 60, 75 and 90 min after intravenous administration of 131I-o-hippurate and the best-fit curve was obtained by means of the least-square method. When the UC was related to the absolute value of the clearance a positive linear correlation was found (r = 0.922, ρ > 0.99). Using this regression equation the clearance could be estimated in reverse from the uptake coefficient calculated solely on the basis of the renoscintigraphic curves without blood sampling. The errors of the estimate are compatible with the requirement of a fast appraisal of renal function for purposes of clinical diagknosis.

Strontium 87m Scanning of Pelvic Bones

1968 ◽  
Vol 07 (01) ◽  
pp. 28-36 ◽  
Author(s):  
Władysław Jasiński ◽  
Janina Malinowska ◽  
Henryk Mackiewicz ◽  
Henryk Siwicki ◽  
Krystyna Lukawska
Keyword(s):  
Body Weight ◽  
Differential Diagnosis ◽  
Early Diagnosis ◽  
Femoral Neck ◽  
Early Period ◽  
Early Recurrence ◽  
Physical Activities ◽  
External Irradiation ◽  
Pelvic Bones ◽  
Strontium 87M

SummaryThe purpose of this investigation was to study the accumulation of 87mSr in the proximal parts of the femoral bones of patients treated previously by external irradiation due to cancer of the uterine cervix. It was assumed that this method may be used in the future for the early diagnosis of postirradiation changes of bone (osteoradionecrosis).The incidence of postirradiation changes of the femoral neck among 5735 patients treated between 1950 and 1961 at the Department of Gynaecology of the Institute, was 0.8%. In the early period of postirradiation changes the patients complain only of pain and limitation of physical activities. If radiological and gynaecological findings were negative, the differential diagnosis between early recurrence and early osteoradionecrosis became impossible.49 selected patients were scanned after intravenous injection of 10—115 μCi of 87mSr per kg of body weight (0.5 up to 6.0 mCi). Illustrative cases of normal pelvic bones as well as postirradiation changes are presented and discussed. The authors conclude that the findings justify further systematic studies on the morphology of accumulation of 87mSr in the bones.

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