Organization and Hormonal Release of Stereotyped Motor Programs from the CNS of an Insect1

2015 ◽  
pp. 1-15 ◽  
Author(s):  
James W. Truman
Keyword(s):  
Motor Programs ◽  
Hormonal Release

Handwriting in Alzheimer’s Disease

2021 ◽  
pp. 1-9
Author(s):  
Margarete Delazer ◽  
Laura Zamarian ◽  
Atbin Djamshidian
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Course ◽  
Typical Feature ◽  
Healthy Controls ◽  
Spearman Correlation ◽  
Writing Difficulties ◽  
Motor Programs ◽  
Processing Level ◽  
Diagnostic Values

Background: Agraphia is a typical feature in the clinical course of Alzheimer’s disease (AD). Objective: Assess the differences between AD and normal aging as regards kinematographic features of handwriting and elucidate writing deficits in AD. Methods: The study included 23 patients with AD (78.09 years/SD = 7.12; MMSE 21.39/SD = 3.61) and 34 healthy controls (75.56 years/SD = 5.85; MMSE 29.06/SD = 0.78). Both groups performed alphabetical and non-alphabetical writing tasks. The kinematographic assessment included the average number of inversions per stroke (NIV; number of peaks in the velocity profile in a single up or down stroke), percentage of automated segments, frequency (average number of strokes per second), writing pressure, and writing velocity on paper. Results: A total of 14 patients showed overt writing difficulties reflected by omissions or substitutions of letters. AD patients showed less automated movements (as measured by NIV), lower writing velocity, and lower frequency of up-and-down strokes in non-alphabetical as well as in alphabetical writing. In the patient group, Spearman correlation analysis between overt writing performance and NIV was significant. That means patients who had less errors in writing a sentence showed a higher automaticity in handwriting. The correctness of alphabetical writing and some kinematographic measures in writing non-alphabetical material reached excellent diagnostic values in ROC analyses. There was no difference in the application of pressure on the pen between patients and controls. Conclusion: Writing disorders are multi-componential in AD and not strictly limited to one processing level. The slow and poorly automated execution of motor programs is not bound to alphabetical material.

scholarly journals Release of a single neurotransmitter from an identified interneuron coherently affects motor output on multiple time scales

2013 ◽  
Vol 109 (9) ◽  
pp. 2327-2334 ◽  
Author(s):  
Andrew M. Dacks ◽  
Klaudiusz R. Weiss
Keyword(s):  
Time Scales ◽  
Motor Program ◽  
Gaba Release ◽  
Motor Output ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Intrinsic Properties ◽  
Buccal Ganglion ◽  
Motor Programs ◽  
Pattern Characteristic

Neurotransmitters can have diverse effects that occur over multiple time scales often making the consequences of neurotransmission difficult to predict. To explore the consequences of this diversity, we used the buccal ganglion of Aplysia to examine the effects of GABA release by a single interneuron, B40, on the intrinsic properties and motor output of the radula closure neuron B8. B40 induces a picrotoxin-sensitive fast IPSP lasting milliseconds in B8 and a slow EPSP lasting seconds. We found that the excitatory effects of this slow EPSP are also mediated by GABA. Together, these two GABAergic actions structure B8 firing in a pattern characteristic of ingestive programs. Furthermore, we found that repeated B40 stimulation induces a persistent increase in B8 excitability that was occluded in the presence of the GABA B receptor agonist baclofen, suggesting that GABA affects B8 excitability over multiple time scales. The phasing of B8 activity during the feeding motor programs determines the nature of the behavior elicited during that motor program. The persistent increase in B8 excitability induced by B40 biased the activity of B8 during feeding motor programs causing the motor programs to become more ingestive in nature. Thus, a single transmitter released from a single interneuron can have consequences for motor output that are expressed over multiple time scales. Importantly, despite the differences in their signs and temporal characteristics, the three actions of B40 are coherent in that they promote B8 firing patterns that are characteristic of ingestive motor outputs.

scholarly journals A Novel Neuronal Pathway for Visually Guided Escape in Drosophila melanogaster

2009 ◽  
Vol 102 (2) ◽  
pp. 875-885 ◽  
Author(s):  
Haleh Fotowat ◽  
Amir Fayyazuddin ◽  
Hugo J. Bellen ◽  
Fabrizio Gabbiani
Keyword(s):  
Drosophila Melanogaster ◽  
Activity Pattern ◽  
Escape Response ◽  
Angular Size ◽  
The Novel ◽  
Visually Guided ◽  
Motor Sequence ◽  
Motor Programs ◽  
Sensory Activity ◽  
Descending Interneurons

Drosophila melanogaster exhibits a robust escape response to objects approaching on a collision course. Although a pair of large command interneurons called the giant fibers (GFs) have been postulated to trigger such behaviors, their role has not been directly demonstrated. Here, we show that escape from visual stimuli like those generated by approaching predators does not rely on the activation of the GFs and consists of a more complex and less stereotyped motor sequence than that evoked by the GFs. Instead, the timing of escape is tightly correlated with the activity of previously undescribed descending interneurons that signal a threshold angular size of the approaching object. The activity pattern of these interneurons shares features with those of visual escape circuits of several species, including pigeons, frogs, and locusts, and may therefore have evolved under similar constraints. These results show that visually evoked escapes in Drosophila can rely on at least two descending neuronal pathways: the GFs and the novel pathway we characterize electrophysiologically. These pathways exhibit very different patterns of sensory activity and are associated with two distinct motor programs.

scholarly journals Motor Programs as Indicators of Penalty Direction in Soccer

2020 ◽  
Vol 8 (9) ◽  
pp. 224-233
Author(s):  
Luiz Felipe Pinto Oliveira da Motta ◽  
Ricardo Fontes Macedo ◽  
Elizabeth Cárpio Rivera ◽  
Angela Luciana De-Bortoli ◽  
Robelius De-Bortoli
Keyword(s):  
Behavior Pattern ◽  
Video Camera ◽  
The Body ◽  
Motor Patterns ◽  
Motor Programs ◽  
Front View ◽  
Elbow Angle ◽  
Patterns Of Behavior ◽  
Prior Intention ◽  
Leg Position

Introduction: Many football games are decided on penalties and usually in championship final games. When seeking to anticipate movements, differences in amplitude can harm players because the informational movement appears to be spread "globally" throughout the action and should be coded at several levels. Thus, it would be interesting to analyze the entire period of the kick, since the player begins his run to approach the ball to recognize the motor patterns used in the kick that identify his direction. Objective: The objective of this study is to identify patterns of behavior in penalty kicks that may indicate the direction of their action / kick and in my moment they appear. Methodology: The sample consisted of 21 subjects hitting a penalty kick, 18 males and 3 females with an average age of 22.18 ± 2.44 years and two goalkeepers with college football experience. The tests consisted of a battery of two penalty kicks for each subject in order to score. The kicks were recorded by a video camera with a front view of the goal goal and the back of the batter. The kick phases were divided into the starting leg position; first step leg; angle of the elbow in relation to the body seen from behind; angle of the elbow in relation to the displacement line seen from above; direction of the tip of the supporting foot and position on the goal where the kick was. Each kick was preceded by a start signal. The data were analyzed from the registration of each variable and the position of the goal in which the ball was kicked, considering it in three sectors: left, right and central. Results: The main results indicated that the variable “Leg of the first step” had 81% of the kicks associated with the direction of the goal; 52.4% of second kicks had repeated the pattern of behavior and 84.6% had repeated the pattern of behavior regardless of the goal position. The variable “Elbow angle in relation to the body seen from behind” had 81.8% repeated behavior pattern regardless of the goal position and the variable “Elbow angle in relation to the displacement line seen from above” had 81% association with the sector of the goal in which the ball was kicked; 52.4% of second kicks had repeated the pattern of behavior and 91.7% had repeated the pattern of behavior regardless of the goal position. Conclusions: The main conclusions indicate that it is possible to relate the kick location with the batter's body information; the start of the race seems to indicate that there is a prior intention of movement programs; the decision of where to hit the penalty appears to be made before contact with the ball and more closely to the placement of the support foot and with this relationship, the size of the goal to be defended by the goalkeeper could be reduced, increasing the possibility of defense.

scholarly journals Thermostabilization and purification of the human dopamine transporter (hDAT) in an inhibitor and allosteric ligand bound conformation

2018 ◽  
Author(s):  
Vikas Navratna ◽  
Dilip K. Tosh ◽  
Kenneth A. Jacobson ◽  
Eric Gouaux
Keyword(s):  
Dopamine Transporter ◽  
Limiting Factor ◽  
Molecular Architecture ◽  
Secondary Active Transport ◽  
Reward Seeking ◽  
Dopamine Reuptake ◽  
Seeking Behavior ◽  
Chemical Messenger ◽  
Hormonal Release ◽  
Detergent Micelles

AbstractThe human dopamine transporter(hDAT) plays a major role in dopamine homeostasis and regulation of neurotransmission by clearing dopamine from the extracellular space using secondary active transport. Dopamine is an essential monoamine chemical messenger that regulates reward seeking behavior, motor control, hormonal release, and emotional response in humans. Psychostimulants such as cocaine primarily target the central binding site of hDAT and lock the transporter in an outward-facing conformation, thereby inhibiting dopamine reuptake. The inhibition of dopamine reuptake leads to accumulation of dopamine in the synapse causing heightened signaling. In addition, hDAT is implicated in various neurological disorders and disease-associated neurodegeneration. Despite its significance, the molecular architecture of hDAT and its various conformational states are poorly understood. Instability of hDAT in detergent micelles has been a limiting factor in its successful biochemical, biophysical, and structural characterization. To overcome this hurdle, first we identified ligands that stabilize hDAT in detergent micelles. Then, we screened ∼200 single residue mutants of hDAT using high-throughput scintillation proximity assay, and identified a thermostable variant(I248Y). Here we report a robust strategy to overexpress and successfully purify a thermostable variant of hDAT in an inhibitor and allosteric ligand bound conformation.

scholarly journals Functional Genetic Screen to Identify Interneurons Governing Behaviorally Distinct Aspects of Drosophila Larval Motor Programs

2016 ◽  
Author(s):  
Matt Q. Clark ◽  
Stephanie J. McCumsey ◽  
Sereno Lopez-Darwin ◽  
Ellie S. Heckscher ◽  
Chris Q. Doe
Keyword(s):  
Motor Neurons ◽  
Animal Behavior ◽  
Motor Program ◽  
Genetic Screen ◽  
Muscle Contractions ◽  
Specific Expression ◽  
Motor Programs ◽  
Secondary Screen ◽  
Forward Locomotion ◽  
Sparse Pattern

AbstractDrosophila larval crawling is an attractive system to study patterned motor output at the level of animal behavior. Larval crawling consists of waves of muscle contractions generating forward or reverse locomotion. In addition, larvae undergo additional behaviors including head casts, turning, and feeding. It is likely that some neurons are used in all these behaviors (e.g. motor neurons), but the identity (or even existence) of neurons dedicated to specific aspects of behavior is unclear. To identify neurons that regulate specific aspects of larval locomotion, we performed a genetic screen to identify neurons that, when activated, could elicit distinct motor programs. We used 165 Janelia CRM-Gal4 lines – chosen for sparse neuronal expression – to express the warmth-inducible neuronal activator TrpA1 and screened for locomotor defects. The primary screen measured forward locomotion velocity, and we identified 63 lines that had locomotion velocities significantly slower than controls following TrpA1 activation (28°C). A secondary screen was performed on these lines, revealing multiple discrete behavioral phenotypes including slow forward locomotion, excessive reverse locomotion, excessive turning, excessive feeding, immobile, rigid paralysis, and delayed paralysis. While many of the Gal4 lines had motor, sensory, or muscle expression that may account for some or all of the phenotype, some lines showed specific expression in a sparse pattern of interneurons. Our results show that distinct motor programs utilize distinct subsets of interneurons, and provide an entry point for characterizing interneurons governing different elements of the larval motor program.

scholarly journals Spastic paresis: impaired spinal reflexes and intact motor programs.

1988 ◽  
Vol 51 (4) ◽  
pp. 568-571 ◽  
Author(s):  
W Berger ◽  
G A Horstmann ◽  
V Dietz
Keyword(s):  
Spinal Reflexes ◽  
Motor Programs ◽  
Spastic Paresis

Motor Control of Tail Spine Rotation of the Horseshoe Crab, Limulus Polyphemus

1973 ◽  
Vol 58 (3) ◽  
pp. 599-625
Author(s):  
GERALD E. SILVEY
Keyword(s):  
Firing Pattern ◽  
Horseshoe Crab ◽  
Limulus Polyphemus ◽  
Muscle Fibres ◽  
Single Muscle ◽  
Nerve Fibres ◽  
Clockwise Rotation ◽  
Motor Programs ◽  
A Minor ◽  
Large Neurons

1. Limulus polyphemus (L.), the horseshoe crab, rotates its tail spine in order to right tself and to keep itself balanced. 2. Eight muscles, discrete bundles of muscle fibres, move the tail spine. Fibres of the muscles contract in sequence and thereby pull consecutively on the several tendons of each muscle in order to rotate the tail spine in either a clockwise or counter-clockwise direction. 3. Motoneurones in nerves to different muscles, fibres within a muscle and units in a nerve to a single muscle fire in different sequences during clockwise and counter-clockwise rotation of the tail spine. 4. The firing pattern consists of a major burst of small to large neurons which fire in clusters, and a minor burst of small neurones which appear to fire randomly. Motoneurones in both bursts are excitatory. The major burst develops tension, the minor burst acts during extension of the muscle and presumably impedes relaxation in order to produce stable deflexion and smooth rotation of the tail spine. 5. Muscle fibres respond to motor output with small excitatory junctional potentials of < 5 mV. E.j.p.s sum and show facilitation, and in some cases develop spike-like potentials of 10-20 mV. Both spiking and the greatest increase in tension occur during the clustered firings in major bursts. 6. Muscle fibres have sarcomere lengths of 6·5±0·8 µm and diameters of 10·60 µm. Nerve fibres range from less than 3 to 32 µm in diameter in large nerve branches, which contain between 50 and 100 fibres. 7. These findings indicate that two different motor programs evoke contraction of muscle fibres in opposite sequences. Sequential contraction of fibres within a muscle means that muscle fibres which are activated together, rather than whole muscles, are the functional contractile entities.

Metabolic and endocrine changes in acute and chronic critical illness

2020 ◽  
pp. 3906-3913
Author(s):  
Eva Boonen ◽  
Greet Van den Berghe
Keyword(s):  
Critical Illness ◽  
Anterior Pituitary ◽  
Chronic Phase ◽  
Stressful Event ◽  
Metabolic Alterations ◽  
Exogenous Substrate ◽  
Chronic Critical Illness ◽  
Substrate Deprivation ◽  
Hormonal Release ◽  
Persistent Critical Illness

Critical illness, an extreme form of severe physical stress, is characterized by important endocrine and metabolic changes. The development of critical care medicine has made possible survival from conditions that were previously rapidly fatel, and as a result many patients now enter a prolonged phase of chronic or persistent critical illness. Acute endocrine adaptations are directed towards providing energy and substrates for the vital fight or flight response in the context of exogenous substrate deprivation. Distinct endocrine and metabolic alterations characterize the chronic phase of critical illness, which seems to no longer be solely beneficial and may hamper recovery and rehabilitation. Onset of the stressful event causes an acute activation of pulsatile hormonal release from the anterior pituitary, followed by suppression in the chronic phase of illness, ultimately resolving to normality if recovery occurs.

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