scholarly journals Entrainment of mammalian motile cilia in the brain with hydrodynamic forces

2020 ◽  
Vol 117 (15) ◽  
pp. 8315-8325 ◽  
Author(s):  
Nicola Pellicciotta ◽  
Evelyn Hamilton ◽  
Jurij Kotar ◽  
Marion Faucourt ◽  
Nathalie Delgehyr ◽  
...  
Keyword(s):  
Hydrodynamic Forces ◽  
Coordination Mechanism ◽  
Similar Frequency ◽  
Brain Ventricles ◽  
Flagellar Beat ◽  
Multiciliated Cells ◽  
Hydrodynamic Screening ◽  
Motile Cilia ◽  
External Flows ◽  
The Brain

Motile cilia are widespread across the animal and plant kingdoms, displaying complex collective dynamics central to their physiology. Their coordination mechanism is not generally understood, with previous work mainly focusing on algae and protists. We study here the entrainment of cilia beat in multiciliated cells from brain ventricles. The response to controlled oscillatory external flows shows that flows at a similar frequency to the actively beating cilia can entrain cilia oscillations. We find that the hydrodynamic forces required for this entrainment strongly depend on the number of cilia per cell. Cells with few cilia (up to five) can be entrained at flows comparable to cilia-driven flows, in contrast with what was recently observed in Chlamydomonas. Experimental trends are quantitatively described by a model that accounts for hydrodynamic screening of packed cilia and the chemomechanical energy efficiency of the flagellar beat. Simulations of a minimal model of cilia interacting hydrodynamically show the same trends observed in cilia.

scholarly journals Synchronization of mammalian motile cilia in the brain with hydrodynamic forces

2019 ◽  
Author(s):  
Nicola Pellicciotta ◽  
Evelyn Hamilton ◽  
Jurij Kotar ◽  
Marion Faucourt ◽  
Nathalie Degehyr ◽  
...  
Keyword(s):  
Mechanistic Model ◽  
Hydrodynamic Forces ◽  
Coordination Mechanism ◽  
Mammalian Brain ◽  
Similar Frequency ◽  
Multiciliated Cells ◽  
Motile Cilia ◽  
External Flows ◽  
The Brain

Motile cilia are widespread across the animal and plant kingdoms, displaying complex collective dynamics central to their physiology. Their coordination mechanism is not generally understood, with pre-vious work mainly focusing on algae and protists. We study here the synchronization of cilia beat in multiciliated cells from brain ven-tricles. The response to controlled oscillatory external flows shows that strong flows at a similar frequency to the actively beating cilia can entrain cilia oscillations. We find that the hydrodynamic forces required for this entrainment strongly depend on the number of cilia per cell. Cells with few cilia (up to five) can be entrained at flows comparable to the cilia-driven flows reported in vivo. Simulations of a minimal model of cilia interacting hydrodynamically show the same trends observed in cilia. Our results suggest that hydrody-namic forces between cilia are sufficient to be the mechanism behind the synchronization of mammalian brain cilia dynamics.Significance StatementIt is shown experimentally, and also reproducing key qualitative results in a minimal mechanistic model simulated numerically, that in the motile cilia of the brain hydrodynamic forces of the magnitude that cilia themselves can generate are sufficient to establish the coordination of dynamics which is so crucial phys-iologically. This is the first experiment of its kind on multicilated cells, the key result is the unexpected importance of cilia num-ber per cell, with cells with fewer cilia much more susceptible to external flows. This finding changes the way in which we think about the question of collective cilia beating - it is not correct to simply examine isolated cilia and draw conclusions about the behaviour of cilia assemblies in multiciliated cells.

scholarly journals Transcription factor TAp73 and microRNA-449 complement each other to support multiciliogenesis

2018 ◽  
Author(s):  
Merit Wildung ◽  
Tilman Uli Esser ◽  
Katie Baker Grausam ◽  
Cornelia Wiedwald ◽  
Larisa Volceanov-Hahn ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Choroid Plexus ◽  
Transcriptional Response ◽  
Transcriptional Regulator ◽  
Male And Female ◽  
Brain Ventricles ◽  
Vital Functions ◽  
Multiciliated Cells ◽  
Genomic Regions ◽  
The Brain

AbstractMotile cilia serve vital functions in development, homeostasis and regeneration. We recently demonstrated that TAp73 is an essential transcriptional regulator of respiratory multiciliogenesis. Here, we show that TAp73 is expressed in multiciliated cells (MCCs) of diverse tissues. Analysis of TAp73 mutant animals revealed that TAp73 regulates Foxj1, Rfx2, Rfx3, axonemal dyneins Dnali1 and Dnai1, plays a pivotal role in the generation of MCCs in male and female reproductive ducts, and contributes to fertility. However, the function of MCCs in the brain appears to be preserved despite the loss of TAp73, and robust activity of cilia-related networks is maintained in the absence of TAp73. Notably, TAp73 loss leads to distinct changes in ciliogenic microRNAs: miR34bc expression is reduced, whereas the miR449 cluster is induced in diverse multiciliated epithelia. Among different MCCs, choroid plexus (CP) epithelial cells in the brain display prominent miR449 expression, whereas brain ventricles exhibit significant increase in miR449 levels along with an increase in the activity of ciliogenic E2F4/MCIDAS circuit in TAp73 mutant animals. Conversely, E2F4 induces robust transcriptional response from miR449 genomic regions. To address whether increased miR449 levels in the brain maintain the multiciliogenesis program in the absence of TAp73, we deleted both TAp73 and miR449 in mice. Although loss of miR449 alone led to a mild ciliary defect in the CP, more pronounced ciliary defects and hydrocephalus were observed in the brain lacking both TAp73 and miR449. In contrast, miR449 loss in other MCCs failed to enhance ciliary defects associated with TAp73 loss. Together, our study shows that, in addition to the airways, TAp73 is essential for generation of MCCs in male and female reproductive ducts, whereas miR449 and TAp73 complement each other to support multiciliogenesis and CP development in the brain.

scholarly journals Computational Modeling of Motile Cilia Generated Cerebral Flow Dynamics in Zebrafish Embryo

2020 ◽  
Author(s):  
Huseyin Enes Salman ◽  
Natalie Jurisch Yaksi ◽  
Huseyin Cagatay Yalcin
Keyword(s):  
Brain Development ◽  
Flow Velocity ◽  
Zebrafish Embryo ◽  
Flow Dynamics ◽  
Csf Flow ◽  
Brain Ventricles ◽  
Ciliary Beating ◽  
Directional Flow ◽  
Motile Cilia ◽  
The Brain

Background: Motile cilia are hair-like microscopic structures, which move the fluids along the epithelial surfaces. Cilia cover a wide range of regions in the nervous system, such as the nasal cavity, spinal cord central canal, and brain ventricles. Motile cilia-driven cerebrospinal fluid (CSF) flow in the brain ventricles has an important role in the brain development. Embryos lacking motile cilia develop neurological defects due to altered CSF flow. Aim: To investigate the effect of motile-cilia motion on the altered CSF flow, and to understand the role of CSF flow in the brain development and physiology. Methods: The dynamics of motile-cilia driven flow is analyzed employing computational fluid dynamics (CFD) modeling. A 2D model is generated using the time-lapse microscopic movies showing movements of a fluorescently labeled motile-cilia in a zebrafish embryo (48-hour post-fertilization). The effects on the generated flow are elucidated by investigating the cilia beating angle, multiple cilia formations, and the phase difference between different ciliary beats. Results: Ciliary beating generated a directional flow in the form of a circulating vortex. The angle of ciliary beating significantly affected the flow velocity. As the angle between the wall and cilia decreases, the flow becomes more efficient by achieving higher velocities. Multiple cilia formations increased the flow velocity but the significance of multiple cilia is not as critical as the beating angle. Interestingly, phase difference between the multiple cilia beats increased the directional flow velocity. Conclusion: Motile-cilia generated flow dynamics are investigated, and it is concluded that out-of-phase multiple ciliary beating is the optimum form of beating in order to generate a directional flow.

scholarly journals Cilia density and flow velocity affect alignment of motile cilia from brain cells

2020 ◽  
Vol 223 (24) ◽  
pp. jeb229310
Author(s):  
Nicola Pellicciotta ◽  
Debasish Das ◽  
Jurij Kotar ◽  
Marion Faucourt ◽  
Nathalie Spassky ◽  
...  
Keyword(s):  
Shear Stress ◽  
Fluid Flow ◽  
Numerical Simulations ◽  
External Flow ◽  
Brain Cells ◽  
Shear Stresses ◽  
Hydrodynamic Screening ◽  
Maturation Stages ◽  
Motile Cilia ◽  
External Flows

ABSTRACTIn many organs, thousands of microscopic ‘motile cilia’ beat in a coordinated fashion generating fluid flow. Physiologically, these flows are important in both development and homeostasis of ciliated tissues. Combining experiments and simulations, we studied how cilia from brain tissue align their beating direction. We subjected cilia to a broad range of shear stresses, similar to the fluid flow that cilia themselves generate, in a microfluidic setup. In contrast to previous studies, we found that cilia from mouse ependyma respond and align to these physiological shear stress at all maturation stages. Cilia align more easily earlier in maturation, and we correlated this property with the increase in multiciliated cell density during maturation. Our numerical simulations show that cilia in densely packed clusters are hydrodynamically screened from the external flow, in agreement with our experimental observation. Cilia carpets create a hydrodynamic screening that reduces the susceptibility of individual cilia to external flows.

scholarly journals The regulatory roles of motile cilia in CSF circulation and hydrocephalus

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Vijay Kumar ◽  
Zobia Umair ◽  
Shiv Kumar ◽  
Ravi Shankar Goutam ◽  
Soochul Park ◽  
...  
Keyword(s):  
Brain Development ◽  
Main Body ◽  
Csf Circulation ◽  
Multiciliated Cells ◽  
Abnormal Accumulation ◽  
Motile Cilia ◽  
The Brain ◽  
Severe Hydrocephalus ◽  
Ependymal Lining

Abstract Background Cerebrospinal fluid (CSF) is an ultra-filtrated colorless brain fluid that circulates within brain spaces like the ventricular cavities, subarachnoid space, and the spine. Its continuous flow serves many primary functions, including nourishment, brain protection, and waste removal. Main body The abnormal accumulation of CSF in brain cavities triggers severe hydrocephalus. Accumulating evidence had indicated that synchronized beats of motile cilia (cilia from multiciliated cells or the ependymal lining in brain ventricles) provide forceful pressure to generate and restrain CSF flow and maintain overall CSF circulation within brain spaces. In humans, the disorders caused by defective primary and/or motile cilia are generally referred to as ciliopathies. The key role of CSF circulation in brain development and its functioning has not been fully elucidated. Conclusions In this review, we briefly discuss the underlying role of motile cilia in CSF circulation and hydrocephalus. We have reviewed cilia and ciliated cells in the brain and the existing evidence for the regulatory role of functional cilia in CSF circulation in the brain. We further discuss the findings obtained for defective cilia and their potential involvement in hydrocephalus. Furthermore, this review will reinforce the idea of motile cilia as master regulators of CSF movements, brain development, and neuronal diseases.

scholarly journals Alcohol consumption impairs the ependymal cilia motility in the brain ventricles

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Alzahra J. Al Omran ◽  
Hannah C. Saternos ◽  
Yusuf S. Althobaiti ◽  
Alexander Wisner ◽  
Youssef Sari ◽  
...  
Keyword(s):  
Alcohol Consumption ◽  
Brain Ventricles ◽  
Ependymal Cilia ◽  
The Brain

Shape differences of the brain ventricles in Alzheimer's disease

NeuroImage ◽  
2006 ◽  
Vol 32 (3) ◽  
pp. 1060-1069 ◽  
Author(s):  
Luca Ferrarini ◽  
Walter M. Palm ◽  
Hans Olofsen ◽  
Mark A. van Buchem ◽  
Johan H.C. Reiber ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Brain Ventricles ◽  
The Brain

History, Anatomy, Histology, and Embryology of the Ventricles and Physiology of the Cerebrospinal Fluid

2021 ◽  
Author(s):  
Pinar Kuru Bektaşoğlu ◽  
Bora Gürer
Keyword(s):  
Cerebrospinal Fluid ◽  
Fluid Secretion ◽  
Colorless Liquid ◽  
Brain Ventricles ◽  
Arachnoid Granulations ◽  
Choroid Plexuses ◽  
Subarachnoid Spaces ◽  
The Mean ◽  
The Brain ◽  
Cerebrospinal Fluid Secretion

Cerebrospinal fluid is an essential, clear, and colorless liquid for the homeostasis of the brain and neuronal functioning. It circulates in the brain ventricles, the cranial and spinal subarachnoid spaces. The mean cerebrospinal fluid volume is 150 ml, with 125 ml in subarachnoid spaces and 25 ml in the ventricles. Cerebrospinal fluid is mainly secreted by the choroid plexuses. Cerebrospinal fluid secretion in adults ranges between 400 and 600 ml per day and it is renewed about four or five times a day. Cerebrospinal fluid is mainly reabsorbed from arachnoid granulations. Any disruption in this well-regulated system from overproduction to decreased absorption or obstruction could lead to hydrocephalus.

Sign in / Sign up

Export Citation Format

Share Document