Neurotransmitters involved in generation of electrical stimulation-evoked rhythmic burst activity in the trigeminal nerve of neonatal mice in vitro

In this study, contributions of left–right reciprocal coupling mediated by commissural interneurons in spinal locomotor networks to rhythmogenesis were examined in larval lamprey that had longitudinal midline lesions in the rostral spinal cord [8 → 30% body length (BL), relative distance from the head] or caudal spinal cord (30 → 50% BL). Motor activity was initiated from brain locomotor command systems in whole animals or in vitro brain/spinal cord preparations. After midline lesions in the caudal spinal cord in whole animals and in vitro preparations, left–right alternating burst activity could be initiated in rostral and usually caudal regions of spinal motor networks. In in vitro preparations, blocking synaptic transmission in the rostral cord abolished burst activity in caudal hemi-spinal cords. After midline lesions in the rostral spinal cord in whole animals, left–right alternating muscle burst activity was present in the caudal and sometimes the rostral body. After spinal cord transections at 30% BL, rhythmic burst activity usually was no longer generated by rostral hemi-spinal cords. For in vitro preparations, very slow burst activity was sometimes present in isolated right and left rostral hemi-spinal cords, but the rhythmicity for this activity appeared to originate from the brain, and the parameters of the activity were significantly different from those for normal locomotor activity. In summary, in larval lamprey under these experimental conditions, left and right hemi-spinal cords did not generate rhythmic locomotor activity in response to descending inputs from the brain, suggesting that left–right reciprocal coupling contributes to both phase control and rhythmogenesis.

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LY53857, a 5HT2 Receptor Antagonist, Delays Occlusion and Inhibits Platelet Aggregation in a Rabbit Model of Carotid Artery Occlusion

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646420 ◽

1991 ◽

Vol 66 (03) ◽

pp. 355-360 ◽

Cited By ~ 4

Author(s):

Harve C Wilson ◽

William Coffman ◽

Anne L Killam ◽

Marlene L Cohen

Keyword(s):

Electrical Stimulation ◽

Platelet Aggregation ◽

Carotid Artery ◽

Receptor Antagonist ◽

Artery Occlusion ◽

Carotid Artery Occlusion ◽

Rabbit Platelet ◽

Rabbit Platelets ◽

5Ht2 Receptor

SummaryThe present study was designed to evaluate the effectiveness of the ergoline 5HT2 receptor antagonist, LY53857 in a rabbit model of vascular arterial occlusion. LY53857 (1 and 10 εM) inhibited serotonin amplified platelet aggregation responses to threshold concentrations of ADP in rabbit platelets in vitro. LY53857 (1 εM) not only inhibited the serotonin component of rabbit platelet aggregation, but also inhibited in vitro aggregation induced by ADP (48.7 ± 16.7% inhibition), collagen (76.1 ± 15.9% inhibition) and U46619 (65.2 ± 12.3% inhibition). The effectiveness of this ergoline 5HT2 receptor antagonist in blocking aggregation to ADP, collagen and U46619 may be related to its ability to inhibit a serotonin component of platelet aggregation since rabbit platelets possess high concentrations of serotonin that may be released during aggregation produced by other agents. Based on the effectiveness of LY53857 to inhibit rabbit platelet aggregation, we explored the ability of LY53857 to extend the time to carotid artery occlusion in rabbits following electrical stimulation of the artery. Reproducible carotid artery occlusion was induced in rabbits by moderate stenosis coupled to arterial cross clamping, followed by electrical stimulation. With this procedure, occlusion occurred at 47.0 ± 7 min (n = 30) after initiation of the electrical stimulation. Animals pretreated with LY53857 (50 to 500 εg/kg i.v.) showed a delay in the time to carotid artery occlusion (at 100 εg/kg i.v. occlusion time extended to 164 ± 16 min). Furthermore, ex vivo platelet aggregation from animals treated with LY53857 (300 εg/kg i.v.) resulted in 40.5% inhibition of platelet aggregation in response to the combination of ADP (1 εM) and serotonin (1 εM). These studies document the ability to obtain reproducible arterial occlusion in the rabbit and showed that intravenously administered LY53857 prolonged the time to carotid artery occlusion. Prolongation of carotid artery occlusion time was accompanied by inhibition of serotonin-amplified ADP-induced aggregation in rabbit platelets, an effect observed both in vitro and ex vivo. Thus, the rabbit is a useful model for studying the effectiveness of 5HT2 receptor antagonists in prolonging vascular occlusion induced by insult of the carotid artery.

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Recycled algae-based carbon materials as electroconductive 3D printed skeletal muscle tissue engineering scaffolds

Journal of Materials Science Materials in Medicine ◽

10.1007/s10856-021-06534-6 ◽

2021 ◽

Vol 32 (7) ◽

Author(s):

Selva Bilge ◽

Emre Ergene ◽

Ebru Talak ◽

Seyda Gokyer ◽

Yusuf Osman Donar ◽

...

Keyword(s):

Skeletal Muscle ◽

Tissue Engineering ◽

Electrical Stimulation ◽

Muscle Tissue ◽

Carbonaceous Material ◽

Hydrothermal Carbonization ◽

Skeletal Muscle Tissue ◽

Myotube Formation ◽

3D Printed

AbstractSkeletal muscle is an electrically and mechanically active tissue that contains highly oriented, densely packed myofibrils. The tissue has self-regeneration capacity upon injury, which is limited in the cases of volumetric muscle loss. Several regenerative therapies have been developed in order to enhance this capacity, as well as to structurally and mechanically support the defect site during regeneration. Among them, biomimetic approaches that recapitulate the native microenvironment of the tissue in terms of parallel-aligned structure and biophysical signals were shown to be effective. In this study, we have developed 3D printed aligned and electrically active scaffolds in which the electrical conductivity was provided by carbonaceous material (CM) derived from algae-based biomass. The synthesis of this conductive and functional CM consisted of eco-friendly synthesis procedure such as pre-carbonization and multi-walled carbon nanotube (MWCNT) catalysis. CM obtained from biomass via hydrothermal carbonization (CM-03) and its ash form (CM-03K) were doped within poly(ɛ-caprolactone) (PCL) matrix and 3D printed to form scaffolds with aligned fibers for structural biomimicry. Scaffolds were seeded with C2C12 mouse myoblasts and subjected to electrical stimulation during the in vitro culture. Enhanced myotube formation was observed in electroactive groups compared to their non-conductive counterparts and it was observed that myotube formation and myotube maturity were significantly increased for CM-03 group after electrical stimulation. The results have therefore showed that the CM obtained from macroalgae biomass is a promising novel source for the production of the electrically conductive scaffolds for skeletal muscle tissue engineering.

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Bioengineered in vitro skeletal muscles as new tools for muscular dystrophies preclinical studies

Journal of Tissue Engineering ◽

10.1177/2041731420981339 ◽

2021 ◽

Vol 12 ◽

pp. 204173142098133

Author(s):

Juan M. Fernández-Costa ◽

Xiomara Fernández-Garibay ◽

Ferran Velasco-Mallorquí ◽

Javier Ramón-Azcón

Keyword(s):

Skeletal Muscle ◽

Tissue Engineering ◽

Electrical Stimulation ◽

Skeletal Muscles ◽

Screening Tools ◽

Muscular Dystrophies ◽

Preclinical Studies ◽

Technological Advances ◽

Topographical Cues

Muscular dystrophies are a group of highly disabling disorders that share degenerative muscle weakness and wasting as common symptoms. To date, there is not an effective cure for these diseases. In the last years, bioengineered tissues have emerged as powerful tools for preclinical studies. In this review, we summarize the recent technological advances in skeletal muscle tissue engineering. We identify several ground-breaking techniques to fabricate in vitro bioartificial muscles. Accumulating evidence shows that scaffold-based tissue engineering provides topographical cues that enhance the viability and maturation of skeletal muscle. Functional bioartificial muscles have been developed using human myoblasts. These tissues accurately responded to electrical and biological stimulation. Moreover, advanced drug screening tools can be fabricated integrating these tissues in electrical stimulation platforms. However, more work introducing patient-derived cells and integrating these tissues in microdevices is needed to promote the clinical translation of bioengineered skeletal muscle as preclinical tools for muscular dystrophies.

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Establishment of a New Device for Electrical Stimulation of Non-Degenerative Cartilage Cells In Vitro

International Journal of Molecular Sciences ◽

10.3390/ijms22010394 ◽

2021 ◽

Vol 22 (1) ◽

pp. 394

Author(s):

Simone Krueger ◽

Alexander Riess ◽

Anika Jonitz-Heincke ◽

Alina Weizel ◽

Anika Seyfarth ◽

...

Keyword(s):

Electrical Stimulation ◽

Electric Fields ◽

Cartilage Tissue ◽

Type I ◽

Dependent Manner ◽

New Device ◽

Alternating Electric Fields ◽

Cartilage Cells ◽

Stimulation Of

In cell-based therapies for cartilage lesions, the main problem is still the formation of fibrous cartilage, caused by underlying de-differentiation processes ex vivo. Biophysical stimulation is a promising approach to optimize cell-based procedures and to adapt them more closely to physiological conditions. The occurrence of mechano-electrical transduction phenomena within cartilage tissue is physiological and based on streaming and diffusion potentials. The application of exogenous electric fields can be used to mimic endogenous fields and, thus, support the differentiation of chondrocytes in vitro. For this purpose, we have developed a new device for electrical stimulation of chondrocytes, which operates on the basis of capacitive coupling of alternating electric fields. The reusable and sterilizable stimulation device allows the simultaneous use of 12 cavities with independently applicable fields using only one main supply. The first parameter settings for the stimulation of human non-degenerative chondrocytes, seeded on collagen type I elastin-based scaffolds, were derived from numerical electric field simulations. Our first results suggest that applied alternating electric fields induce chondrogenic re-differentiation at the gene and especially at the protein level of human de-differentiated chondrocytes in a frequency-dependent manner. In future studies, further parameter optimizations will be performed to improve the differentiation capacity of human cartilage cells.

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