Morphological Changes Following Ultraviolet Microbeam Irradiation of Parts of Nuclei of Living Cells

1967 ◽  
Vol 32 (4) ◽  
pp. 849 ◽  
Author(s):  
Sensuke Naruse ◽  
Rhuichi Yatani ◽  
Susumu Takeda
Keyword(s):  
Morphological Changes ◽  
Living Cells ◽  
Microbeam Irradiation ◽  
Ultraviolet Microbeam

scholarly journals Design of an imaging probe to monitor real-time redistribution of L-type voltage gated calcium channels in astrocytic glutamate signalling

2020 ◽  
Author(s):  
Mitra Sadat Tabatabaee ◽  
Jeff Kerkovius ◽  
Frederic Menard
Keyword(s):  
Calcium Channels ◽  
Real Time ◽  
Morphological Changes ◽  
Fold Increase ◽  
Living Cells ◽  
Confocal Imaging ◽  
Excitatory Neurotransmitter ◽  
Imaging Probe ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channels

ABSTRACTPurposeIn the brain, astrocytes are non-excitable cells that undergo rapid morphological changes when stimulated by the excitatory neurotransmitter glutamate. We developed a chemical probe to monitor how glutamate affects the density and distribution of astrocytic L-type voltage-gated calcium channels (LTCC).ProceduresThe imaging probe FluoBar1 was created from a barbiturate ligand modified with a fluorescent coumarin moiety. The probe selectivity was examined with colocalization analyses of confocal fluorescence imaging in U118-MG and transfected COS-7 cells. Living cells treated with 50 nM FluoBar1 were imaged in real time to reveal changes in density and distribution of astrocytic LTCCs upon exposure to glutamate.ResultsFluoBar1 was synthesized in ten steps. The selectivity of the probe was demonstrated with immunoblotting and confocal imaging of immunostained cells expressing the CaV1.2 isoform of LTCCs proteins. Applying FluoBar1 to astrocyte model cells U118-MG allowed us to measure a 5-fold increase in fluorescence density of LTCCs upon glutamate exposure.ConclusionsImaging probe FluoBar1 allows the real-time monitoring of LTCCs in living cells, revealing for first time that glutamate causes a rapid increase of LTCC membranar density in astrocyte model cells. FluoBar1 may help tackle previously intractable questions about LTCC dynamics in cellular events.

scholarly journals Methods and applications of label-free cell-based systems

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Joachim Wiest
Keyword(s):  
Environmental Monitoring ◽  
Morphological Changes ◽  
Free Cell ◽  
Living Cells ◽  
Label Free ◽  
Controlled System ◽  
Chip Technology ◽  
Cell Monitoring ◽  
A Cell ◽  
On Chip

Label-free monitoring of living cells is used in various applications such as drug development, toxicology, regenerative medicine or environmental monitoring. The most prominent methods for monitoring the extracellular acidification, oxygen consumption, electrophysiological activity and morphological changes of living cells are described. Furthermore, the intelligent mobile lab (IMOLA) – a computer controlled system integrating cell monitoring and automated cell cultivation – is described as an example of a cell-based system for microphysiometry. Results from experiments in the field of environmental monitoring using algae are presented. An outlook toward the development of an organ-on-chip technology is given.

scholarly journals ULTRAVIOLET MICROBEAM IRRADIATION IN LIVING CELL MEMBRANES

1965 ◽  
Vol 26 (3) ◽  
pp. 959-961
Author(s):  
P. O'B. Montgomery ◽  
James E. Cook ◽  
David Karney
Keyword(s):  
Living Cell ◽  
Cell Membranes ◽  
Microbeam Irradiation ◽  
Ultraviolet Microbeam

The Action of Formaldehyde on Living Cells as Studied by Phase-contrast Microscopy

1951 ◽  
Vol s3-92 (20) ◽  
pp. 403-452
Author(s):  
C. N.C. CRAWFORD ◽  
R. BARER
Keyword(s):  
Phase Contrast ◽  
Morphological Changes ◽  
Cytoplasmic Inclusion ◽  
Living Cells ◽  
Cell Swelling ◽  
Phase Contrast Microscopy ◽  
Chemical Action ◽  
Short Period ◽  
Contrast Microscopy ◽  
Constant Observation

The morphological changes occurring when living cells are fixed in neutralized formaldehyde have been studied in detail with phase-contrast microscopy. The cells used were (i) salamander spermatogonia obtained from the teased testis, and (2) ssnail amoebocytes growing in tissue culture. The cells were mounted on a slide beneath a coverslip ringed with paraffin wax. Various strengths of formaldehyde made up in saline or distilled water were then introduced while the cells were kept under constant observation by phase-contrast microscopy. The morphological changes during the fixation process were observed for periods of at least 24 hours and the results recorded photographically. The main changes observed with aqueous formaldehyde were: A. Cell swelling or shrinkage. In general (e.g. with 5 per cent, formaldehyde) the cell tended to undergo (1) an initial short period of shrinkage, (2) a period of re-expansion followed by swelling, (3) a period of secondary shrinkage. The initial shrinkage appeared less in the amoebocytes than in the spermatogonia, but otherwise their volume changes were fairly similar. If the strength of formaldehyde was below 5 per cent, the initial shrinkage was very slight and subsequent swelling great. With 1 per cent, formaldehyde, sudden collapse of the cell followed swelling. With formalde-hyde concentrations above 10 per cent, the initial shrinkage was greater and was followed by little or no swelling. B. Formation of ‘bubbles’ from the cells. Clear bubble-like structures often emerged from the spermatogonia during fixation. They were most frequently formed in 5 per cent, formaldehyde. Increasing the strength of the formaldehyde decreased both the number and size of the ‘bubbles’. It is suggested that they may represent an escape of substance through a damaged cell boundary. Similar bubble-like swellings formed in the amoebocytes, but they usually seemed to remain within the cell processes. C. Nuclear changes. Changes in the size of the nucleus ran approximately parallel with those of the cell, but tended to be somewhat less and with different time relation-ships. With swelling the nucleoplasm became more homogeneous and with gross swelling the heterochromatic bodies disappeared. After prolonged fixation, when the nucleus may have undergone secondary shrinkage, pre-existing nuclear opacities became denser and new opacities sometimes appeared in previously homogeneous regions. Bubbles sometimes emerged from the nucleus. D. Changes in cytoplasmic structure. In general with prolonged fixation a fine granularity or reticular opacities formed in previously homogeneous cytoplasm. Clear vacuoles also appeared in the cytoplasm after fixation in the more concentrated solutions. The cytoplasmic inclusion bodies were usually well preserved and their appearance little altered. With formaldehyde made up in saline as opposed to water the initial shrinkage was increased and the subsequent swelling reduced. This effect was most pronounced with dilute formaldehyde. The addition of saline seemed to have little influence on changes in nuclear and cytoplasmic texture, and bubbling, though less in degree, still occurred. The significance of these observations is discussed in the light of modern views on the physico-chemical action of formaldehyde.

A Theory of the Behavior of Paramecium Aurelia and Behavioral Effects of Feeding, Fission, and Ultraviolet Microbeam Irradiation

Behaviour ◽  
1960 ◽  
Vol 15 (1-2) ◽  
pp. 82-122 ◽  
Author(s):  
Donald D. Jensen
Keyword(s):  
Particulate Matter ◽  
Culture Fluid ◽  
Suture Line ◽  
Pacemaker Activity ◽  
Microbeam Irradiation ◽  
Ultraviolet Microbeam ◽  
Research Problems ◽  
The Subject ◽  
Food Bacteria ◽  
Ciliary Beat

AbstractParamecium aurelia is the subject of a theory of behavior composed of postulates describing the presence, action, and interaction of three pacemakers: a posterior pacemaker which produces ciliary beat backward along the kineties; a buccal pacemaker which produces ciliary beat toward the suture line and the buccal overture in the vestibulum ; and an anterior pacemaker which produces ciliary beat away from the suture line and the buccal overture in the vestibulum and forward along the kineties elsewhere. Commonly observed behaviors of paramecia are derived from the theory and six experiments relevant to the theory are described. In three experiments, the culture medium in which paramecia were observed was varied. Presence of bacteria and non-nutritive particulate matter decreased swimming scores and increased swimming turn rates. In one of these experiments prior as well as immediate presence of bacteria in culture fluid varied. Prior availability of food bacteria increased swimming scores and contact turn rates. These results are consistent with the theory if it is assumed that immediate presence of particulate matter increases buccal pacemaker activity and that prior availability of food bacteria increases posterior pacemaker activity. In another experiment animals were observed during and following binary fission. During fission swimming scores decreased, and following fission the proters had lower swimming scores and contact turn rates than opisthes. These results are consistent with the theory if it is assumed that periods in which all ciliary beat is absent occur in parent animals during fission, and in proters following fission. Such periods were observed in dividing animals. Opisthes had higher swimming turn rates following fission than prior to it; this result is consistent with the theory if it is assumed that newly organized buccal pacemakers are unusually active. In two other experiments, the anterior tips, buccal cavities, and posterior tips of paramecia were subjected to ultraviolet microbeam irradiation. Irradiated animals moved more during and immediately following irradiation than they moved prior to irradiation or than control animals did. Posteriorly irradiated animals moved forward, anteriorly irradiated animals moved backward. Irradiation also influenced behavior during a subsequent two-minute observation period. Anteriorly irradiated animals had higher swimming scores, lower contact turn rates, and a greater tendency to swim backward. Animals irradiated in the buccal cavity had lower swimming turn rates and higher swimming turn durations; posteriorly irradiated animals had lower swimming scores, contact turn rates, and swimming turn rates. These results are consistent with the theory if pacemakers near irradiated areas are temporarily activated by irradiation and are hyposensitive and hyperreactive following irradiation. A number of research problems were suggested.

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