scholarly journals Hypothalamic dopamine neurons control sensorimotor behavior by modulating brainstem premotor nuclei

2020 ◽  
Author(s):  
Joshua P. Barrios ◽  
Wei-Chun Wang ◽  
Roman England ◽  
Erica Reifenberg ◽  
Adam D. Douglass
Keyword(s):  
Sensorimotor Integration ◽  
Motor Behavior ◽  
Third Ventricle ◽  
Dopamine Neurons ◽  
Preoptic Nucleus ◽  
Anatomy And Physiology ◽  
Motor Behaviors ◽  
Hypothalamic Nuclei ◽  
The Brain ◽  
Hypothalamic Dopamine

SummaryDopamine (DA)-producing neurons are critically involved in the production of motor behaviors in multiple circuits that are conserved from basal vertebrates to mammals. While there is increasing evidence that DA neurons in the hypothalamus play a locomotor role, their precise contributions to behavior and the circuit mechanisms by which they are achieved remain unclear. Here we demonstrate that tyrosine hydroxylase 2-expressing (th2+) DA neurons in the zebrafish hypothalamus fire phasic bursts of activity to acutely promote swimming and modulate audiomotor behaviors on fast timescales. Their anatomy and physiology reveal two distinct functional DA modules within the hypothalamus. The first comprises an interconnected set of cerebrospinal fluid-contacting DA nuclei surrounding the third ventricle, which lack distal projections outside of the hypothalamus and influence locomotion through unknown means. The second includes neurons in the preoptic nucleus, which send long-range projections to targets throughout the brain, including the mid- and hindbrain, where they activate premotor circuits involved in swimming and sensorimotor integration. These data suggest a broad regulation of motor behavior by DA neurons within multiple hypothalamic nuclei and elucidate a novel functional mechanism for the preoptic DA neurons in the initiation of movement.

scholarly journals Output Units of Motor Behavior: An Experimental and Modeling Study

2000 ◽  
Vol 12 (1) ◽  
pp. 78-97 ◽  
Author(s):  
E. P. Loeb ◽  
S. F. Giszter ◽  
P. Saltiel and E. Bizzi ◽  
F. A. Mussa-Ivaldi
Keyword(s):  
Motor Control ◽  
Common Property ◽  
Motor Behavior ◽  
Muscle Synergies ◽  
Force Output ◽  
Time Dynamics ◽  
Motor Behaviors ◽  
Distinct Property ◽  
Small Set ◽  
The Brain

Cognitive approaches to motor control typically concern sequences of discrete actions without taking into account the stunning complexity of the geometry and dynamics of the muscles. This begs the question: Does the brain convert the intricate, continuous-time dynamics of the muscles into simpler discrete units of actions, and if so, how? One way for the brain to form discrete units of behavior from muscles is through the synergistic co-activation of muscles. While this possibility has long been known, the composition of potential muscle synergies has remained elusive. In this paper, we have focused on a method that allowed us to examine and compare the limb stabilization properties of all possible muscle combinations. We found that a small set (as few as 23 out of 65,536) of all possible combinations of 16 limb muscles are robust with respect to activation noise: these muscle combinations could stabilize the limb at predictable, restricted portions of the workspace in spite of broad variations in the force output of their component muscles. The locations at which the robust synergies stabilize the limb are not uniformly distributed throughout the leg's workspace, but rather, they cluster at four workspace areas. The simulated robust synergies are similar to the actual synergies we have previously found to be generated by activation of the spinal cord. Thus, we have developed a new analytical method that enabled us to select a few muscle synergies with interesting properties out of the set of possible muscle combinations. Beyond this, the identification of robustness as a common property of the synergies in simple motor behaviors will open the way to the study of dynamic stability, which is an important and distinct property of the vertebrate motor-control system.

Lack of Adaptation to Random Conflicting Force Fields of Variable Magnitude

2007 ◽  
Vol 97 (1) ◽  
pp. 738-745 ◽  
Author(s):  
Rahul Gupta ◽  
James Ashe
Keyword(s):  
Motor Behavior ◽  
Force Fields ◽  
Human Subjects ◽  
Large Body ◽  
Internal Models ◽  
Limited Capacity ◽  
Contextual Cues ◽  
Motor Behaviors ◽  
Extended Practice ◽  
The Brain

The concept of internal models has been used to explain how the brain learns and stores a variety of motor behaviors. A large body of work has shown that conflicting internal models could not be learned simultaneously; this suggests either a limited capacity or the unstable nature of short-term motor memories. However, it has been recently shown that multiple conflicting internal models of motor behavior could be acquired simultaneously if associated with appropriate contextual cues and random presentations. We re-examined this issue in a more complex environment in which the magnitude of the conflicting fields could vary randomly. Human subjects failed to show any evidence of learning the force fields themselves or the magnitude of the forces experienced, even with extended practice. Subjects did adapt to the applied perturbation when the field strength was kept constant but still did not form internal models. Our results show that neither random presentation nor specific contextual cues are sufficient for learning conflicting internal models when the magnitude of the forces is also unpredictable. The data suggest that multiple conflicting internal models cannot be learned in all environments, and provide support for the unstable nature or limited capacity of motor memories.

Effects of central sodium on epithelial sodium channels in rat brain

2010 ◽  
Vol 299 (1) ◽  
pp. R222-R233 ◽  
Author(s):  
Hong-Wei Wang ◽  
Md Shahrier Amin ◽  
Esraa El-Shahat ◽  
Bing S. Huang ◽  
Balwant S. Tuana ◽  
...  
Keyword(s):  
Choroid Plexus ◽  
Supraoptic Nucleus ◽  
Third Ventricle ◽  
Brain Regions ◽  
Neural Precursor Cells ◽  
Epithelial Sodium Channels ◽  
Artificial Cerebrospinal Fluid ◽  
Hypothalamic Nuclei ◽  
Hypothalamic Tissue ◽  
The Brain

We evaluated the effects of intracerebroventricular (icv) infusion of Na+-rich artificial cerebrospinal fluid (aCSF), with or without the mineralocorticoid receptor (MR) blocker spironolactone, on epithelial Na+ channel (ENaC) subunits and regulators, such as MR, serum/glucocorticoid-inducible kinase 1, neural precursor cells expressed developmentally downregulated 4-like gene, 11β-hydroxylase, and aldosterone synthase, in brain regions of Wistar rats. The effects of icv infusion of the amiloride analog benzamil on brain tissue and CSF Na+ concentration ([Na+]) were also assessed. In the choroid plexus and ependyma of the anteroventral third ventricle, ENaC subunits are present in apical and basal membranes. Na+-rich aCSF increased β-ENaC mRNA and immunoreactivity in the choroid plexus and increased α- and β-ENaC immunoreactivities in the ependyma. Na+-rich aCSF increased α- and β-ENaC-gold-labeled particles in the microvilli of the choroid plexus and in basolateral membranes of the ependyma. Spironolactone only prevented the increase in β-ENaC immunoreactivity in the choroid plexus and ependyma. In the supraoptic nucleus, paraventricular nucleus, and subfornical organ, Na+-rich aCSF did not affect mRNA expression levels of the studied genes. Benzamil significantly increased CSF [Na+] in the control, but not Na+-rich, aCSF group. In contrast, benzamil prevented the increase in hypothalamic tissue [Na+] by Na+-rich aCSF. These results suggest that CSF Na+ upregulates ENaC expression in the brain epithelia, but not in the neurons of hypothalamic nuclei. ENaC in the choroid plexus and ependyma appear to contribute to regulation of Na+ homeostasis in the brain.

scholarly journals Active neural coordination of motor behaviors with internal states

2021 ◽  
Author(s):  
Yisi S. Zhang ◽  
Daniel Y. Takahashi ◽  
Ahmed El Hady ◽  
Diana A. Liao ◽  
Asif A. Ghazanfar
Keyword(s):  
Motor Behavior ◽  
Cardiac Activity ◽  
Motor Behaviors ◽  
Spontaneous Movements ◽  
Causal Ordering ◽  
Heart Rate Fluctuations ◽  
Internal States ◽  
Network States ◽  
Medial Section ◽  
The Brain

AbstractThe brain continuously coordinates skeletomuscular movements with internal physiological states like arousal, but how is this coordination achieved? One possibility is that brain simply reacts to changes in external and/or internal signals. Another possibility is that it is actively coordinating both external and internal activities. We used functional ultrasound imaging to capture a large medial section of the brain, including multiple cortical and subcortical areas, in marmoset monkeys while monitoring their spontaneous movements and cardiac activity. By analyzing the causal ordering of these different time-series, we found that information flowing from the brain to movements and heart rate fluctuations were significantly greater than in the opposite direction. The brain areas involved in this external versus internal coordination were spatially distinct but also extensively interconnected. Temporally, the brain alternated between network states for this regulation. These findings suggest that the brain’s dynamics actively and efficiently coordinate motor behavior with internal physiology.

scholarly journals Movement errors during skilled motor performance engage distinct prediction error mechanisms

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Ella Gabitov ◽  
Ovidiu Lungu ◽  
Geneviève Albouy ◽  
Julien Doyon
Keyword(s):  
Prediction Error ◽  
Motor Behavior ◽  
Prediction Errors ◽  
Unexpected Events ◽  
Sensorimotor Network ◽  
Motor Behaviors ◽  
Neural Computations ◽  
Adaptive Processes ◽  
Reward Valuation ◽  
The Brain

AbstractThe brain detects deviations from intended behaviors by estimating the mismatch between predicted and actual outcomes. Axiomatic to these computations are salience and valence prediction error signals, which alert the brain to the occurrence and value of unexpected events. Despite the theoretical assertion of these prediction error signals, it is unknown whether and how brain mechanisms underlying their computations support error processing during skilled motor behavior. Here we demonstrate, with functional magnetic resonance imaging, that internal detection, i.e., without externally-provided feedback, of self-generated movement errors evokes instantaneous activity increases within the salience network and delayed lingering decreases within the nucleus accumbens – a key structure in the reward valuation pathway. A widespread suppression within the sensorimotor network was also observed. Our findings suggest that neural computations of salience and valence prediction errors during skilled motor behaviors operate on different time-scales and, therefore, may contribute differentially to immediate and longer-term adaptive processes.

scholarly journals Unilateral Botulinum Neurotoxin-A Injection into the Striatum of C57BL/6 Mice Leads to a Different Motor Behavior Compared with Rats

Toxins ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 295 ◽  
Author(s):  
Veronica Antipova ◽  
Andreas Wree ◽  
Carsten Holzmann ◽  
Teresa Mann ◽  
Nicola Palomero-Gallagher ◽  
...  
Keyword(s):  
Botulinum Neurotoxin ◽  
Sensorimotor Integration ◽  
Motor Behavior ◽  
Morphological Changes ◽  
Botulinum Neurotoxin A ◽  
Motor Behaviors ◽  
The Right ◽  
Rats And Mice ◽  
Forelimb Preference ◽  
Intrastriatal Injection

Different morphological changes in the caudate-putamen (CPu) of naïve rats and mice were observed after intrastriatal botulinum neurotoxin-A (BoNT-A) injection. For this purpose we here studied various motor behaviors in mice (n = 46) longitudinally up to 9 months after intrastriatal BoNT-A administration as previously reported for rats, and compared both outcomes. Apomorphine- and amphetamine-induced rotational behavior, spontaneous motor behavior, as well as lateralized neglect were studied in mice after the injection of single doses of BoNT-A into the right CPu, comparing them with sham-injected animals. Unilateral intrastriatal injection of BoNT-A in mice induced significantly increased contralateral apomorphine-induced rotations for 1 to 3 months, as well as significantly increased contralateral amphetamine-induced rotations 1 to 9 months after injection. In rats (n = 28), unilateral BoNT-A injection also induced significantly increased contralateral apomorphine-induced rotations 3 months after injection, but did not provoke amphetamine-induced rotations at all. Lateralized sensorimotor integration, forelimb preference, and forelimb stepping were significantly impaired on the left side. The differences in motor behaviors between rats and mice may be caused by different BoNT-A effects on cholinergic and catecholaminergic fibers in rat and mouse striata, interspecies differences in striatal receptor densities, and different connectomes of the basal ganglia.

Experimental Third Ventriculostomy Performed Using Endovascular Surgical Techniques and Their Adaptation to Percutaneous Intradural Neuronavigation: Proof of Concept Cadaver Study

Neurosurgery ◽  
2003 ◽  
Vol 53 (2) ◽  
pp. 387-392 ◽  
Author(s):  
Michael B. Horowitz ◽  
Kamal Ramzipoor ◽  
Ajit Nair ◽  
Susan Miller ◽  
George Rappard ◽  
...  
Keyword(s):  
Third Ventricle ◽  
Surgical Techniques ◽  
Cadaver Study ◽  
Brain Parenchyma ◽  
Third Ventriculostomy ◽  
General Anesthetic ◽  
The Third ◽  
Noncommunicating Hydrocephalus ◽  
Pass Through ◽  
The Brain

Abstract OBJECTIVE Endoscopic third ventriculostomy has developed into a therapeutic alternative to shunting for the management of carefully selected patients with primarily noncommunicating hydrocephalus. This procedure, however, requires a general anesthetic and necessitates violation of the brain parenchyma and manipulation near vital neural structures to access the floor of the third ventricle. Using two cadavers and off-the-shelf angiographic catheters, we sought to determine whether it was possible to navigate a catheter, angioplasty balloon, and stent percutaneously through the subarachnoid space from the thecal sac into the third ventricle so as to perform a third ventriculostomy from below. METHODS Using biplane angiography and off-the-shelf angiographic catheters along with angioplasty balloons and stents, we were able to pass a stent coaxially from the thecal sac to and across the floor of the third ventricle so as to achieve a third ventriculostomy from below. RESULTS Coaxial catheter techniques allowed for the percutaneous insertion of a stent across the floor of the third ventricle. Ventriculostomy was confirmed by injecting contrast medium into the lateral ventricle and seeing it pass through the stent and into the chiasmatic cistern. CONCLUSION We describe the performance of third ventriculostomies in two cadavers by use of the new concept of percutaneous intradural neuronavigation. This procedure may obviate the need for general anesthetic and minimize the potential for brain and vascular injury, especially if ultimately combined with magnetic resonance fluoroscopy.

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