scholarly journals Dynamics and variability of neuronal subtype responses during growth, degrowth, and regeneration

2019 ◽  
Author(s):  
Jamie A. Havrilak ◽  
Layla Al-Shaer ◽  
Noor Baban ◽  
Nesli Akinci ◽  
Michael J. Layden
Keyword(s):  
Nervous System ◽  
Body Size ◽  
Caloric Intake ◽  
Body Axis ◽  
Whole Body ◽  
Fluorescent Reporter ◽  
Nerve Net ◽  
Neuronal Subtype ◽  
Neuronal Number

AbstractBackgroundWe are interested in nervous system dynamics in adult and regenerating animals. Preliminary studies suggest that some species alter neuronal number to scale with changes in body size. Similarly, in some species regenerates resulting from wholebody axis regeneration are smaller than their pre-amputated parent, but they maintain the correct proportionality, suggesting that tissue and neuronal scaling also occurs in regenerates. The cell dynamics and responses of neuronal subtypes during nervous system regeneration, scaling, and whole-body axis regeneration are not well understood in any system. The cnidarian sea anemone Nematostella vectensis is capable of wholebody axis regeneration, and its transparent, “simple” body plan and the availability of fluorescent reporter transgenic lines allow neuronal subtypes to be tracked in vivo in adult and regenerating animals. A number of observations suggest this anemone is able to alter its size in responses to changes in feeding. We utilized the NvLWamide-like::mCherry neuronal subtype transgenic reporter line to determine the in vivo response of neuronal subtypes during growth, degrowth, and regeneration.ResultsNematostella alters its size in response to caloric intake, and the nervous system responds by altering neuronal number to scale as the animal changes in size. Neuronal numbers in both the endodermal and ectodermal nerve nets decreased as animals shrunk, increased as they grew, and the changes were reversible. Whole-body axis regeneration resulted in regenerates that were smaller than their pre-amputated size, and the regenerated nerve nets were reduced in neuronal number. Different neuronal subtypes had several distinct responses during regeneration that included consistent, no, and conditional increases in number. Conditional responses were regulated, in part, by the size of the remnant fragment and the position of the amputation site. Regenerates and adults with reduced nerve nets displayed normal behaviors, indicating that the nerve net retains functionality as it scales.ConclusionThese data suggest that the Nematostella nerve net is dynamic, capable of scaling with changes in body size, and that neuronal subtypes display differential regenerative responses, which we propose may be linked to the scale state of the regenerating animals.

scholarly journals Characterization of the dynamics and variability of neuronal subtype responses during growth, degrowth, and regeneration of Nematostella vectensis

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jamie A. Havrilak ◽  
Layla Al-Shaer ◽  
Noor Baban ◽  
Nesli Akinci ◽  
Michael J. Layden
Keyword(s):  
Nervous System ◽  
Body Size ◽  
Body Axis ◽  
Whole Body ◽  
Nematostella Vectensis ◽  
Body Parts ◽  
Fluorescent Reporter ◽  
Nerve Net ◽  
Neuronal Number

Abstract Background The ability to regenerate body parts is a feature of metazoan organisms and the focus of intense research aiming to understand its basis. A number of mechanisms involved in regeneration, such as proliferation and tissue remodeling, affect whole tissues; however, little is known on how distinctively different constituent cell types respond to the dynamics of regenerating tissues. Preliminary studies suggest that a number of organisms alter neuronal numbers to scale with changes in body size. In some species with the ability of whole-body axis regeneration, it has additionally been observed that regenerates are smaller than their pre-amputated parent, but maintain the correct morphological proportionality, suggesting that scaling of tissue and neuronal numbers also occurs. However, the cell dynamics and responses of neuronal subtypes during nervous system regeneration, scaling, and whole-body axis regeneration are not well understood in any system. The cnidarian sea anemone Nematostella vectensis is capable of whole-body axis regeneration, with a number of observations suggesting the ability to alter its size in response to changes in feeding. We took advantage of Nematostella’s transparent and “simple” body plan and the NvLWamide-like mCherry fluorescent reporter transgenic line to probe the response of neuron populations to variations in body size in vivo in adult animals during body scaling and regeneration. Results We utilized the previously characterized NvLWamide-like::mCherry transgenic reporter line to determine the in vivo response of neuronal subtypes during growth, degrowth, and regeneration. Nematostella alters its size in response to caloric intake, and the nervous system responds by altering neuronal number to scale as the animal changes in size. Neuronal numbers in both the endodermal and ectodermal nerve nets decreased as animals shrunk, increased as they grew, and these changes were reversible. Whole-body axis regeneration resulted in regenerates that were smaller than their pre-amputated size, and the regenerated nerve nets were reduced in neuronal number. Different neuronal subtypes had distinct responses during regeneration, including consistent, not consistent, and conditional increases in number. Conditional responses were regulated, in part, by the size of the remnant fragment and the position of the amputation site. Regenerates and adults with reduced nerve nets displayed normal behaviors, indicating that the nerve net retains functionality as it scales. Conclusion These data suggest that the Nematostella nerve net is dynamic, capable of scaling with changes in body size, and that neuronal subtypes display differential regenerative responses, which we propose may be linked to the scale state of the regenerating animals.

scholarly journals Whole-body imaging of neural and muscle activity during behavior in Hydra: bidirectional effects of osmolarity on contraction bursts

2019 ◽  
Author(s):  
Wataru Yamamoto ◽  
Rafael Yuste
Keyword(s):  
Nervous System ◽  
Body Size ◽  
Neuronal Activity ◽  
Environmental Conditions ◽  
Muscle Activity ◽  
Muscle Cells ◽  
Major Effect ◽  
Whole Body ◽  
Effect Of Temperature ◽  
Whole Body Imaging

AbstractThe neural code relates the activity of the nervous system to the activity of the muscles to the generation of behavior. To decipher it, it would be ideal to comprehensively measure the activity of the entire nervous system and musculature in a behaving animal. As a step in this direction, we used the cnidarian Hydra vulgaris to explore how physiological and environmental conditions alter the activity of the entire neural and muscle tissue and affect behavior. We used whole-body calcium imaging of neurons and muscle cells and studied the effect of temperature, media osmolarity, nutritional state and body size on body contractions.In mounted Hydra, changes in temperature, nutrition or body size did not have a major effect on neural or muscle activity, or on behavior. But changes in media osmolarity altered body contractions, increasing them in hipo-osmolar media solutions and decreasing them in hyperosmolar media. Similar effects were seen in ectodermal, but not in endodermal muscle. Osmolarity also bidirectionally changed the activity of contraction bursts neurons, but not of rhythmic potential neurons.These findings show osmolarity-dependent changes in neuronal activity, muscle activity, and contractions, consistent with the hypothesis that contraction burst neurons respond to media osmolarity, activating ectodermal muscle to generate contraction bursts. This dedicated circuit could serve as an excretory system to prevent osmotic injury. This work demonstrates the feasibility of studying the entire neuronal and muscle activity of behaving animals.Significance StatementWe imaged whole-body muscle and neuronal activity in Hydra in response to different physiological and environmental conditions. Osmolarity bidirectionally altered Hydra contractile behavior. These changes were accompanied by corresponding changes in the activity of one neuronal circuit and one set of muscles. This work is a step toward comprehensive deciphering of the mechanisms of animal behavior by measuring the activity of all neurons and muscle cells.

scholarly journals The Reissner Fiber is Highly Dynamic in vivo and Controls Morphogenesis of the Spine

2019 ◽  
Author(s):  
Benjamin Troutwine ◽  
Paul Gontarz ◽  
Ryoko Minowa ◽  
Adrian Monstad-Rios ◽  
Mia J. Konjikusic ◽  
...  
Keyword(s):  
Nervous System ◽  
Embryonic Development ◽  
Dynamic Properties ◽  
Central Canal ◽  
The Body ◽  
Body Axis ◽  
List Type ◽  
The Central Nervous System ◽  
Spine Morphogenesis

SummarySpine morphogenesis requires the integration of multiple musculoskeletal tissues with the nervous system. Cerebrospinal fluid (CSF) physiology is important for development and homeostasis of the central nervous system and its disruption has been linked to scoliosis in zebrafish [1, 2]. Suspended in the CSF is an enigmatic glycoprotein thread called the Reissner fiber, which is secreted from the subcomissural organ (SCO) in the brain and extends caudally through the central canal to where it terminates at the base of the spinal cord. In zebrafish, scospondin null mutants are unable to assemble the Reissner fiber and fail to extend a straight body axis during embryonic development [3]. Here, we describe zebrafish hypomorphic missense alleles, which assemble the Reissner fiber and straighten the body axis during early embryonic development, yet progressively lose the fiber, concomitant with the emergence of body curvature, alterations in neuronal gene expression, and scoliosis in adults. Using an endogenously tagged scospondin-GFP zebrafish knock-in line, we directly visualized Reissner fiber dynamics during the normal development and during the progression of scoliosis, and demonstrate that the Reissner fiber is critical for the morphogenesis of the spine. Our study establishes a framework for future investigations of mechanistic roles of the Reissner fiber including its dynamic properties, molecular interactions, and how these processes are involved in the regulation of spine morphogenesis and scoliosis.HighlightsHypomorphic mutations in zebrafish scospondin result in progressive scoliosisThe disassembly of the Reissner fiber in scospondin hypomorphic mutants results in the strong upregulation of neuronal receptors and synaptic transport componentsAn endogenous fluorescent knock-in allele of scospondin reveals dynamic properties of the Reissner fiber during zebrafish developmentLoss of the Reissner fiber during larval development is a common feature of zebrafish scoliosis models

scholarly journals Diet-induced modulation of mitochondrial activity in rat muscle

2007 ◽  
Vol 293 (5) ◽  
pp. E1169-E1177 ◽  
Author(s):  
Laurent Didier ◽  
Britttany Yerby ◽  
Richard Deacon ◽  
Jiaping Gao
Keyword(s):  
Mitochondrial Dysfunction ◽  
Dietary Intervention ◽  
Caloric Intake ◽  
Atp Synthesis ◽  
Whole Body ◽  
Acid Oxidation ◽  
Mitochondrial Activity ◽  
Chow Diet ◽  
Intramyocellular Lipid

Growing evidence supports the theory that mitochondrial dysfunction is an underlying cause of intramyocellular lipid (IMCL) accumulation and insulin resistance. Here, we hypothesized that high dietary fat (HF) intake could trigger changes in mitochondrial activity such that fatty acid oxidation is impaired in muscle and contributes to an elevation in intramyocellular lipid (IMCL) levels. Muscle mitochondrial activity was determined in vivo through measurement of the F1 F0 ATP synthase flux, the terminal step in the oxidative phosphorylation process. An initial study comparing rats on normal chow diet with rats on an HF diet revealed strong correlations between muscle ATP synthesis rates, IMCL levels and whole body glucose tolerance. Results obtained from two latter studies showed multiphasic responses to dietary intervention. Initially, the ATP synthesis rates decreased as much as 50% within 24 h of raising the fat content in the diet to 60% of the caloric intake. These rates eventually returned to normal values after 2–3 wk on the HF regimen, seemingly to prevent further IMCL accumulation. Only beyond 1 mo on the HF diet did results consistently show ATP synthesis rates to diminish by 30–50% accompanied by steadily augmenting IMCL levels. Interestingly, switching back to a chow diet after 3 wk of HF feeding reversed the initial diet-induced changes. Although the muscle mitochondrial system may initially offer enough compliance to counteract lipid surplus, these in vivo data suggest a vicious long-term cycle among mitochondrial dysfunction, IMCL accumulation, and glucose intolerance in the rat.

scholarly journals Essential Role of Pten in Body Size Determination and Pancreatic β-Cell Homeostasis In Vivo

2006 ◽  
Vol 26 (12) ◽  
pp. 4511-4518 ◽  
Author(s):  
Kinh-Tung T. Nguyen ◽  
Panteha Tajmir ◽  
Chia Hung Lin ◽  
Nicole Liadis ◽  
Xu-Dong Zhu ◽  
...  
Keyword(s):  
Body Size ◽  
Cell Function ◽  
Regulatory Elements ◽  
Negative Regulator ◽  
Whole Body ◽  
Β Cells ◽  
Β Cell ◽  
Critical Determinant ◽  
Insulin Promoter

ABSTRACT PTEN (phosphatase with tensin homology) is a potent negative regulator of phosphoinositide 3-kinase (PI3K)/Akt signaling, an evolutionarily conserved pathway that signals downstream of growth factors, including insulin and insulin-like growth factor 1. In lower organisms, this pathway participates in fuel metabolism and body size regulation and insulin-like proteins are produced primarily by neuronal structures, whereas in mammals, the major source of insulin is the pancreatic β cells. Recently, rodent insulin transcription was also shown in the brain, particularly the hypothalamus. The specific regulatory elements of the PI3K pathway in these insulin-expressing tissues that contribute to growth and metabolism in higher organisms are unknown. Here, we report PTEN as a critical determinant of body size and glucose metabolism when targeting is driven by the rat insulin promoter in mice. The partial deletion of PTEN in the hypothalamus resulted in significant whole-body growth restriction and increased insulin sensitivity. Efficient PTEN deletion in β cells led to increased islet mass without compromise of β-cell function. Parallel enhancement in PI3K signaling was found in PTEN-deficient hypothalamus and β cells. Together, we have shown that PTEN in insulin-transcribing cells may play an integrative role in regulating growth and metabolism in vivo.

Monitoring stem cell migration in the nervous system by in vivo magnetic resonance imaging

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S692-S692
Author(s):  
Mathias Hoehn ◽  
Uwe Himmelreich ◽  
Ralph Weber ◽  
Pedro Ramos-Cabrer ◽  
Susanne Wegener ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Nervous System ◽  
Stem Cell ◽  
Cell Migration ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Stem Cell Migration

Neuropharmacological Profile and Chemical Analysis of Moroccan Ormenis mixta L.

2018 ◽  
Vol 16 (S1) ◽  
pp. S55-S64
Author(s):  
G. Hajjaj ◽  
A. Bahlouli ◽  
M. Tajani ◽  
K. Alaoui ◽  
Y. Cherrah ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Weight ◽  
Traditional Medicine ◽  
Behavioral Tests ◽  
Phytochemical Screening ◽  
Activity Profile ◽  
Acute Toxicity Study ◽  
Pharmacological Studies

Ormenis mixta L. is traditionally used for central nervous system (CNS)-related diseases. Its anti-stress properties have received attention in Moroccan traditional medicine and aromatherapy. However, no pharmacological studies have yet been undertaken on this plant in Morocco. The present study provides a preliminary phytochemical screening and psychopharmacological profile of the essential oil and aqueous extract from Ormenis mixta L. by using behavioral tests in vivo, at graded doses. The result of this research shows that Ormenis mixta L. was safe up to 2 g/kg b.w. (body weight) in the acute toxicity study, possesses potential psychostimulant effect, and has antianxiety and antidepressant-like activity. This activity profile of Ormenis mixta L. was similar to the typical psychostimulant, caffeine. The exact mechanism of action underlying this stimulant-like effect should be clarified with further detailed studies. These results explained the extensive use of Ormenis mixta L. as a traditional medicine in Morocco.

Sign in / Sign up

Export Citation Format

Share Document