scholarly journals Rapid propagation of membrane tension at a presynaptic terminal

2021 ◽  
Author(s):  
Carolina Gomis Perez ◽  
Natasha R Dudzinski ◽  
Mason Rouches ◽  
Benjamin Machta ◽  
David Zenisek ◽  
...  
Keyword(s):  
Chromaffin Cells ◽  
Cell Types ◽  
Synaptic Activity ◽  
Membrane Tension ◽  
Cell Type ◽  
Membrane Flow ◽  
Common View ◽  
The Common ◽  
Adrenal Chromaffin ◽  
Stimulation Of

Many cellular activities, such as cell migration1, cell division, signaling, infection, phagocytosis and exo-endocytosis, generate membrane tension gradients that in turn regulate them. Moreover, membrane flows, which are driven by tension gradients, can limit exo-endocytosis coupling in space and time, as net membrane flow from exocytic to endocytic sites is required to maintain membrane homeostasis. However, there is controversy over how rapidly plasma membrane flows can relax tension gradients; contrary to the common view, recent work showed membrane tension does not equilibrate in several cell types. Here we show membrane tension can propagate rapidly or slowly, spanning orders of magnitude in speed, depending on cell type. In a neuronal terminal specialized for rapid synaptic vesicle turnover and where exo-endocytosis events occur at distinct loci, membrane tension equilibrates within seconds. By contrast, membrane tension does not propagate in neuroendocrine adrenal chromaffin cells secreting catecholamines. Thus, slow membrane flow and tension equilibration may confine exo- and exocytosis to the same loci. Stimulation of exocytosis causes a rapid, global decrease in the synaptic terminal membrane tension, which recovers slowly due to endocytosis. Our results demonstrate membrane tension propagates rapidly at neuronal terminals and varies during synaptic activity, likely contributing to exo-endocytosis coupling.

scholarly journals Common cell type nomenclature for the mammalian brain

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Jeremy A Miller ◽  
Nathan W Gouwens ◽  
Bosiljka Tasic ◽  
Forrest Collman ◽  
Cindy TJ van Velthoven ◽  
...  
Keyword(s):  
Cell Types ◽  
Data Driven ◽  
Mammalian Brain ◽  
Gene Transcript ◽  
Cell Type ◽  
Sequencing Technologies ◽  
Multiple Organs ◽  
Source Data ◽  
The Common ◽  
Common Cell

The advancement of single-cell RNA-sequencing technologies has led to an explosion of cell type definitions across multiple organs and organisms. While standards for data and metadata intake are arising, organization of cell types has largely been left to individual investigators, resulting in widely varying nomenclature and limited alignment between taxonomies. To facilitate cross-dataset comparison, the Allen Institute created the common cell type nomenclature (CCN) for matching and tracking cell types across studies that is qualitatively similar to gene transcript management across different genome builds. The CCN can be readily applied to new or established taxonomies and was applied herein to diverse cell type datasets derived from multiple quantifiable modalities. The CCN facilitates assigning accurate yet flexible cell type names in the mammalian cortex as a step toward community-wide efforts to organize multi-source, data-driven information related to cell type taxonomies from any organism.

scholarly journals Using computer simulations to determine the limitations of dynamic clamp stimuli applied at the soma in mimicking distributed conductance sources

2011 ◽  
Vol 105 (5) ◽  
pp. 2610-2624 ◽  
Author(s):  
Risa J. Lin ◽  
Dieter Jaeger
Keyword(s):  
Computer Simulations ◽  
Dendritic Tree ◽  
Cell Types ◽  
Cerebellar Nuclei ◽  
Realistic Model ◽  
Pattern Generation ◽  
Synaptic Activity ◽  
Dynamic Clamp ◽  
Neuronal Responses ◽  
Cell Type

In previous studies we used the technique of dynamic clamp to study how temporal modulation of inhibitory and excitatory inputs control the frequency and precise timing of spikes in neurons of the deep cerebellar nuclei (DCN). Although this technique is now widely used, it is limited to interpreting conductance inputs as being location independent; i.e., all inputs that are biologically distributed across the dendritic tree are applied to the soma. We used computer simulations of a morphologically realistic model of DCN neurons to compare the effects of purely somatic vs. distributed dendritic inputs in this cell type. We applied the same conductance stimuli used in our published experiments to the model. To simulate variability in neuronal responses to repeated stimuli, we added a somatic white current noise to reproduce subthreshold fluctuations in the membrane potential. We were able to replicate our dynamic clamp results with respect to spike rates and spike precision for different patterns of background synaptic activity. We found only minor differences in the spike pattern generation between focal or distributed input in this cell type even when strong inhibitory or excitatory bursts were applied. However, the location dependence of dynamic clamp stimuli is likely to be different for each cell type examined, and the simulation approach developed in the present study will allow a careful assessment of location dependence in all cell types.

Parametric Finite Element Analysis of Physical Stimuli Resulting From Mechanical Stimulation of Tissue Engineered Cartilage

2008 ◽  
Author(s):  
Omotunde M. Babalola ◽  
Lawrence J. Bonassar
Keyword(s):  
Finite Element Analysis ◽  
Cell Types ◽  
Cartilage Tissue ◽  
Low Density ◽  
Cell Type ◽  
Element Analysis ◽  
Physical Stimuli ◽  
Parametric Finite Element Analysis ◽  
Engineered Cartilage ◽  
Stimulation Of

The avascular nature of cartilage results in its limited inability to repair itself upon injury. As a result numerous approaches are being investigated as potential therapies for repair, including tissue engineering strategies. In addition, due to the low density of chondrocytes and the characteristic de-differentiation of the cells when expanded in monolayer [1], other cell types are being investigated as a source for cartilage repair as well. Mesenchymal stem cells (MSCs), which have been shown to differentiate into cells of several lineages including chondrocytes, osteoblasts and adipocytes [2], are being explored as a potential cell type for the regeneration of articular cartilage tissue [3,4].

scholarly journals Histological and histochemical characterization of the secretory cells of Choeradoplana iheringi Graff, 1899 (Platyhelminthes: Tricladida: Terricola)

2004 ◽  
Vol 64 (3a) ◽  
pp. 511-522 ◽  
Author(s):  
S. A. de Souza ◽  
A. M. Leal-Zanchet
Keyword(s):  
Secretory Cell ◽  
Basic Protein ◽  
Cell Types ◽  
Secretory Cells ◽  
Mucous Secretion ◽  
Cell Type ◽  
The Common ◽  
First Time ◽  
Histochemical Characterization

The present study aims at providing a detailed description of the histology, as well as the first histochemical characterization, of the secretory cells of the epidermis, pharynx, and copulatory organs of Choeradoplana iheringi, in order to give further support to studies on the physiology of these organs. The secretory cells are distinguished on the basis of secretion morphology and its staining properties, using trichrome methods and histochemical reactions. Four cell types open through the epidermis of Ch. iheringi, three of them secreting basic protein and a fourth containing glycosaminoglycan mucins. The epidermal lining cells store glycogen. In the pharynx, four secretory cell types were distinguished. Two types produce glycoprotein, a third type secretes basic protein, and another one produces glycosaminoglycan mucins. In the male copulatory organs, the prostatic vesicle receives four secretory cell types containing basic protein, except for one type which produces glycoprotein. The two secretory cell types opening into the male atrium secrete, respectively, glycoprotein, and glycosaminoglycan mucins. In the female copulatory organs, the female atrium and its proximal diverticulum, the vagina, receive two types of secretory cells producing, respectively, basic protein and glycosaminoglycan mucins. Another secretory cell type constitutes the so-called shell glands which open into the common glandular duct, secreting basic protein. The lining cells of the male and female atria produce a mucous secretion containing glycosaminoglycans. In addition, the lining epithelium of the female atrium presents an apical secretion of a proteic nature. The occurrence of a kind of spermatophore is reported for the first time for a species of Choeradoplana. This structure is located in the male or female atria in different specimens, and characterized by erythrophil, xanthophil, and/or mixed secretions associated with sperm.

scholarly journals Histaminic stimulation of catecholamine release and calcium influx in cultured bovine adrenal chromaffin cells

1989 ◽  
Vol 49 ◽  
pp. 186
Author(s):  
Yasuko Ishimura ◽  
Atsushi Nakanishi ◽  
Masanori Yoshizumi ◽  
Yoshihiro Murakumo ◽  
Kyoji Morita ◽  
...  
Keyword(s):  
Chromaffin Cells ◽  
Calcium Influx ◽  
Catecholamine Release ◽  
Adrenal Chromaffin Cells ◽  
Adrenal Chromaffin ◽  
Stimulation Of

A comparison of bradykinin, angiotensin II and muscarinic stimulation of cultured bovine adrenal chromaffin cells

1989 ◽  
Vol 9 (2) ◽  
pp. 243-252 ◽  
Author(s):  
A. J. O'Sullivan ◽  
R. D. Burgoyne
Keyword(s):  
Angiotensin Ii ◽  
Chromaffin Cells ◽  
Calcium Concentration ◽  
Calcium Entry ◽  
Free Calcium ◽  
Adrenal Chromaffin Cells ◽  
Free Calcium Concentration ◽  
Adrenal Chromaffin ◽  
External Calcium ◽  
Stimulation Of

Bradykinin, angiotensin II and a mascarnic agonist, acetyl-B-methacholine (methacholine) were all found to elict catecholamine release from cultured bovine adrenal chromaffin cells. Bradykinin was the most potent of these secretagogues and methacholine the weakest, with angiotenin II intermediate in efficacy. All three secretagogues were much less effective than nicotinic stimulation. The three secretagogues all produced a rise in cytoplasmic free calcium concentration ([Ca2+]i), measured with the fluorescent indicator fura2, which was partially independent of external calcium. In the case of bradykinin the full rise in ([Ca2+]i) may involve a component of calcium entry in addition to release of calcium from an internal store. Secretion was also found to be partially independent of external calcium. The different efficacies of the three secretagogues in elicting secretion were correlated with the rise in ([Ca2+]i) produced. The differeing efficacies of the three secretagogues may be due to the extent of release of calcium from an intracellular store which itself is less effective in eliciting secretion than a rise in [Ca2+]i following calcium entry due to nicotine. Bradykinin also stimulates calcium entry, and this may increase the efficacy of the initial rise in [Ca2+]i. Treatment with pertussis toxin resulted in an enhancement of secretion in response to all of the secretagogues.

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