Differential activation of octopaminergic (DUM) neurones via proprioceptors responding to flight muscle contractions in the locust

The synaptic potentials generated in neuromodulatory octopaminergic dorsal unpaired median (DUM) neurones by afferents excited by twitch contractions of a dorso-ventral flight muscle were investigated in the locust. Responses to stimulation of the metathoracic wing elevator muscle 113 were obtained in locusts in which all sensory feedback from the thorax had been removed, except for feedback from the thoracic chordotonal organs, the axons of which enter via the purely sensory nerve 2. Afferents in nerve 2C, which originates from two chordotonal organs, responded reliably to twitch contractions of this flight muscle. Octopaminergic neurones innervating leg muscles (DUM5 neurones) received depolarising inputs and often spiked following stimulation of the muscle. In contrast, those innervating the wing muscles themselves (DUM3 and DUM3,4 neurones) received inhibitory inputs. The responses of DUM3,4,5 neurones, which project mainly to leg muscles, were more complex: most were excited by twitch contractions of M113 but some were inhibited. DUMDL, which innervates the dorsal longitudinal indirect flight muscles, showed no clear response. Direct stimulation of nerve 2C evoked depolarising inputs and spikes in DUM5 neurones and hyperpolarising inputs in DUM3 and DUM3,4 neurones. Our data suggest that sensory feedback from thoracic chordotonal organs, which are known to be activated rhythmically during flight, contributes to the differential activation of efferent DUM neurones observed during flight.

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Myofibril and mitochondria morphogenesis are coordinated by a mechanical feedback mechanism in muscle

Nature Communications ◽

10.1038/s41467-021-22058-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jerome Avellaneda ◽

Clement Rodier ◽

Fabrice Daian ◽

Nicolas Brouilly ◽

Thomas Rival ◽

...

Keyword(s):

Striated Muscle ◽

Flight Muscle ◽

Mitochondrial Dynamics ◽

Feedback Mechanism ◽

Mitochondrial Fusion ◽

Sarcomeric Proteins ◽

Muscle Type ◽

Leg Muscles ◽

Flight Muscles ◽

Mechanical Feedback

AbstractComplex animals build specialised muscles to match specific biomechanical and energetic needs. Hence, composition and architecture of sarcomeres and mitochondria are muscle type specific. However, mechanisms coordinating mitochondria with sarcomere morphogenesis are elusive. Here we use Drosophila muscles to demonstrate that myofibril and mitochondria morphogenesis are intimately linked. In flight muscles, the muscle selector spalt instructs mitochondria to intercalate between myofibrils, which in turn mechanically constrain mitochondria into elongated shapes. Conversely in cross-striated leg muscles, mitochondria networks surround myofibril bundles, contacting myofibrils only with thin extensions. To investigate the mechanism causing these differences, we manipulated mitochondrial dynamics and found that increased mitochondrial fusion during myofibril assembly prevents mitochondrial intercalation in flight muscles. Strikingly, this causes the expression of cross-striated muscle specific sarcomeric proteins. Consequently, flight muscle myofibrils convert towards a partially cross-striated architecture. Together, these data suggest a biomechanical feedback mechanism downstream of spalt synchronizing mitochondria with myofibril morphogenesis.

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The calcium sensitivity of ATP ase activity of myofibrils and actomyosins from insect flight and leg muscles

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1968.0008 ◽

1968 ◽

Vol 169 (1016) ◽

pp. 229-240 ◽

Cited By ~ 18

Keyword(s):

Flight Muscle ◽

Insect Flight ◽

Locusta Migratoria ◽

Calcium Sensitivity ◽

Mechanical Activity ◽

Rabbit Muscle ◽

Leg Muscles ◽

Structural Peculiarities ◽

Flight Muscles ◽

Leg Muscle

Myofibrils and actomyosin suspension were prepared from the fibrillar flight and non-fibrillar leg muscles of the water-bug, Lethocerus maximus , and their ATP ase activity measured in solutions of various ionic strength containing Mg ATP . Leg muscle showed a low ATP ase in the absence of Ca 2+ , and a large increase of ATPase over a narrow range of Ca 2+ concentration. Flight muscle had a greater ATPase in the absence of Ca 2+ but showed a much smaller increase over a wider range of Ca 2+ concentration. A similar difference between flight and leg muscle was found in the honey-bee, Apis mellifera , and the beetle, Oryctes rhinoceros , both of which have fibrillar flight muscles, but was not found in the locust, Locusta migratoria , which has non-fibrillar flight muscle. Tryptic digestion raised the ATP ase in the absence of Ca 2+ , and abolished the Ca 2+ -activation, in both flight and leg-muscle preparations from the water-bug; addition of ‘native tropomyosin5 prepared from rabbit muscle partially reversed the effect. These results are discussed in relation to the structural peculiarities and oscillatory mechanical activity of fibrillar flight muscle.

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Dactyl Sensory Influences on Rock Lobster Locomotion: I. Intrasegmental and Intersegmental leg Reflexes During Standing and Walking

Journal of Experimental Biology ◽

10.1242/jeb.148.1.89 ◽

1990 ◽

Vol 148 (1) ◽

pp. 89-112

Author(s):

U. W. E. MÜLLER ◽

FRANÇOIS CLARAC

Keyword(s):

Sensory Nerve ◽

Forward Direction ◽

Power Stroke ◽

Rock Lobster ◽

Step Cycle ◽

Return Stroke ◽

Leg Muscles ◽

Walking Pattern ◽

Lift Off ◽

Stimulation Of

1. Recordings of activity of the rock lobster dactyl sensory nerve during walking on a driven belt showed that the receptors of this nerve were mainly active during the power stroke when the leg was loaded. This nerve contains in particular the afferent fibres of the funnel canal organ (FCO) which are bimodal sensillae located in the cuticle of the dactylopodite of crustacean walking legs. 2. In the standing animal, brief electrical stimulation of the dactyl nerve had an influence on the proximal leg muscles of the stimulated leg. The promotor and levator muscles were excited and the remotor and depressor muscles were inhibited. 3. The opposite reaction was observed in adjacent ipsilateral legs in response to stimulation of a middle leg: the promotor and levator were inhibited and the remotor and depressor excited. 4. The resulting movement by the stimulated leg was stereotyped and always consisted of a lift-off from the substratum and a slight shift in the forward direction. The response in the adjacent legs was not powerful enough to elicit a movement. 5. In the walking animal the response of a single leg was dependent on the phase at which a stimulus arrived during the step cycle: during a power stroke (PS) this cycle was interrupted and a return stroke (RS) was initiated and continued. A stimulation at the normal switch from PS to RS had little effect, whereas a stimulation at late RS very often delayed the start of the following PS. Opposite reactions were given by the adjacent unstimulated legs: an RS was interrupted and a PS initiated or prolonged by the stimulus. 6. A comparison between ipsilateral walking legs showed the existence of some obvious differences: legs 4 and 5 were able to reset the walking pattern of all the legs, whereas the more anterior leg 3 returned to its old trajectory after stimulation and thus had no influence on the other legs.

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EXPERIMENTS ON THE DIRECT STIMULATION OF THE SECRETION CAPACITY OF ADRENAL CORTEX BY THYROID HORMONES

Acta Endocrinologica ◽

10.1530/acta.0.056s205 ◽

1967 ◽

Vol 56 (1_Suppl) ◽

pp. S205

Author(s):

H. V. Henning ◽

P. M. Reisert

Keyword(s):

Thyroid Hormones ◽

Adrenal Cortex ◽

Direct Stimulation ◽

Stimulation Of

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Muscles

10.1093/oso/9780199674923.003.0020 ◽

2018 ◽

Author(s):

Iain A. Anderson ◽

Benjamin M. O’Brien

Keyword(s):

Sensory Feedback ◽

Artificial Muscles ◽

Combustion Engines ◽

Electric Motors ◽

Home Appliances ◽

Leg Muscles ◽

Mechanical Devices ◽

Control Surfaces

Mechanical devices that include home appliances, automobiles, and airplanes are typically driven by electric motors or combustion engines through gearboxes and other linkages. Airplane wings, for example, have hinged control surfaces such as ailerons. Now imagine a wing that has no hinged control surfaces or linkages but that instead bends or warps to assume an appropriate shape, like the wing of a bird. Such a device could be enabled using an electro-active polymer technology based on electronic artificial muscles. Artificial muscles act directly on a structure, like our leg muscles that are attached by tendon to our bones and that through phased contraction enable us to walk. Sensory feedback from our muscles enables proprioceptive control. So, for artificial muscles to be used appropriately we need to pay attention not only to mechanisms for muscle actuation but also to how we can incorporate self-sensing feedback for the control of position.

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The Role of BMP Signaling in Osteoclast Regulation

Journal of Developmental Biology ◽

10.3390/jdb9030024 ◽

2021 ◽

Vol 9 (3) ◽

pp. 24

Author(s):

Brian Heubel ◽

Anja Nohe

Keyword(s):

Bone Formation ◽

Bone Morphogenetic Proteins ◽

Bone Diseases ◽

Bmp Signaling ◽

Bone Homeostasis ◽

Direct Stimulation ◽

Federal Drug Administration ◽

Bmp Pathway ◽

Stimulation Of

The osteogenic effects of Bone Morphogenetic Proteins (BMPs) were delineated in 1965 when Urist et al. showed that BMPs could induce ectopic bone formation. In subsequent decades, the effects of BMPs on bone formation and maintenance were established. BMPs induce proliferation in osteoprogenitor cells and increase mineralization activity in osteoblasts. The role of BMPs in bone homeostasis and repair led to the approval of BMP2 by the Federal Drug Administration (FDA) for anterior lumbar interbody fusion (ALIF) to increase the bone formation in the treated area. However, the use of BMP2 for treatment of degenerative bone diseases such as osteoporosis is still uncertain as patients treated with BMP2 results in the stimulation of not only osteoblast mineralization, but also osteoclast absorption, leading to early bone graft subsidence. The increase in absorption activity is the result of direct stimulation of osteoclasts by BMP2 working synergistically with the RANK signaling pathway. The dual effect of BMPs on bone resorption and mineralization highlights the essential role of BMP-signaling in bone homeostasis, making it a putative therapeutic target for diseases like osteoporosis. Before the BMP pathway can be utilized in the treatment of osteoporosis a better understanding of how BMP-signaling regulates osteoclasts must be established.

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KATP channel blockers control glucagon secretion by distinct mechanisms: a direct stimulation of α-cells involving a [Ca2+]c rise and an indirect inhibition mediated by somatostatin

Molecular Metabolism ◽

10.1016/j.molmet.2021.101268 ◽

2021 ◽

pp. 101268

Author(s):

Bilal Singh ◽

Firas Khattab ◽

Heeyoung Chae ◽

Lieven Desmet ◽

Pedro L. Herrera ◽

...

Keyword(s):

Katp Channel ◽

Glucagon Secretion ◽

Channel Blockers ◽

Direct Stimulation ◽

Stimulation Of

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Electrical stimulation of retinal neurons in epiretinal and subretinal configuration using a multicapacitor array

Journal of Neurophysiology ◽

10.1152/jn.00909.2011 ◽

2012 ◽

Vol 107 (10) ◽

pp. 2742-2755 ◽

Cited By ~ 79

Author(s):

Max Eickenscheidt ◽

Martin Jenkner ◽

Roland Thewes ◽

Peter Fromherz ◽

Günther Zeck

Keyword(s):

Electrical Stimulation ◽

Ganglion Cells ◽

Ex Vivo ◽

Biophysical Model ◽

Retinal Neurons ◽

Direct Stimulation ◽

Tungsten Electrode ◽

Partial Restoration ◽

Low Amplitude ◽

Stimulation Of

Electrical stimulation of retinal neurons offers the possibility of partial restoration of visual function. Challenges in neuroprosthetic applications are the long-term stability of the metal-based devices and the physiological activation of retinal circuitry. In this study, we demonstrate electrical stimulation of different classes of retinal neurons with a multicapacitor array. The array—insulated by an inert oxide—allows for safe stimulation with monophasic anodal or cathodal current pulses of low amplitude. Ex vivo rabbit retinas were interfaced in either epiretinal or subretinal configuration to the multicapacitor array. The evoked activity was recorded from ganglion cells that respond to light increments by an extracellular tungsten electrode. First, a monophasic epiretinal cathodal or a subretinal anodal current pulse evokes a complex burst of action potentials in ganglion cells. The first action potential occurs within 1 ms and is attributed to direct stimulation. Within the next milliseconds additional spikes are evoked through bipolar cell or photoreceptor depolarization, as confirmed by pharmacological blockers. Second, monophasic epiretinal anodal or subretinal cathodal currents elicit spikes in ganglion cells by hyperpolarization of photoreceptor terminals. These stimuli mimic the photoreceptor response to light increments. Third, the stimulation symmetry between current polarities (anodal/cathodal) and retina-array configuration (epi/sub) is confirmed in an experiment in which stimuli presented at different positions reveal the center-surround organization of the ganglion cell. A simple biophysical model that relies on voltage changes of cell terminals in the transretinal electric field above the stimulation capacitor explains our results. This study provides a comprehensive guide for efficient stimulation of different retinal neuronal classes with low-amplitude capacitive currents.

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Characterization of components of Z-bands in the fibrillar flight muscle of Drosophila melanogaster.

The Journal of Cell Biology ◽

10.1083/jcb.109.5.2157 ◽

1989 ◽

Vol 109 (5) ◽

pp. 2157-2167 ◽

Cited By ~ 78

Author(s):

J D Saide ◽

S Chin-Bow ◽

J Hogan-Sheldon ◽

L Busquets-Turner ◽

J O Vigoreaux ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Monoclonal Antibodies ◽

Flight Muscle ◽

Cross Reactivity ◽

Antigenic Determinants ◽

Immunogold Staining ◽

Thick Filaments ◽

The Matrix ◽

Flight Muscles

Twelve monoclonal antibodies have been raised against proteins in preparations of Z-disks isolated from Drosophila melanogaster flight muscle. The monoclonal antibodies that recognized Z-band components were identified by immunofluorescence microscopy of flight muscle myofibrils. These antibodies have identified three Z-disk antigens on immunoblots of myofibrillar proteins. Monoclonal antibodies alpha:1-4 recognize a 90-100-kD protein which we identify as alpha-actinin on the basis of cross-reactivity with antibodies raised against honeybee and vertebrate alpha-actinins. Monoclonal antibodies P:1-4 bind to the high molecular mass protein, projectin, a component of connecting filaments that link the ends of thick filaments to the Z-band in insect asynchronous flight muscles. The anti-projectin antibodies also stain synchronous muscle, but, surprisingly, the epitopes here are within the A-bands, not between the A- and Z-bands, as in flight muscle. Monoclonal antibodies Z(210):1-4 recognize a 210-kD protein that has not been previously shown to be a Z-band structural component. A fourth antigen, resolved as a doublet (approximately 400/600 kD) on immunoblots of Drosophila fibrillar proteins, is detected by a cross reacting antibody, Z(400):2, raised against a protein in isolated honeybee Z-disks. On Lowicryl sections of asynchronous flight muscle, indirect immunogold staining has localized alpha-actinin and the 210-kD protein throughout the matrix of the Z-band, projectin between the Z- and A-bands, and the 400/600-kD components at the I-band/Z-band junction. Drosophila alpha-actinin, projectin, and the 400/600-kD components share some antigenic determinants with corresponding honeybee proteins, but no honeybee protein interacts with any of the Z(210) antibodies.

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